Fix rotated jpeg image save

This resolves Bug 1444

4 files changed, 2244 insertions, 8 deletions

diff --git a/digikam/libs/jpegutils/jpegint.h b/digikam/libs/jpegutils/jpegint.h
index 27546f36..bf01aa3e 100644
--- a/digikam/libs/jpegutils/jpegint.h
+++ b/digikam/libs/jpegutils/jpegint.h
@@ -1,3 +1,421 @@
+#if JPEG_LIB_VERSION >= 80
+
+/*
+ * jpegint.h
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * Modified 1997-2009 by Guido Vollbeding.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides common declarations for the various JPEG modules.
+ * These declarations are considered internal to the JPEG library; most
+ * applications using the library shouldn't need to include this file.
+ */
+
+
+/* Ensuring definition INT32 */
+#ifndef INT32
+#define INT32	TQ_INT32
+#endif
+
+/* Declarations for both compression & decompression */
+
+typedef enum {			/* Operating modes for buffer controllers */
+	JBUF_PASS_THRU,		/* Plain stripwise operation */
+	/* Remaining modes require a full-image buffer to have been created */
+	JBUF_SAVE_SOURCE,	/* Run source subobject only, save output */
+	JBUF_CRANK_DEST,	/* Run dest subobject only, using saved data */
+	JBUF_SAVE_AND_PASS	/* Run both subobjects, save output */
+} J_BUF_MODE;
+
+/* Values of global_state field (jdapi.c has some dependencies on ordering!) */
+#define CSTATE_START	100	/* after create_compress */
+#define CSTATE_SCANNING	101	/* start_compress done, write_scanlines OK */
+#define CSTATE_RAW_OK	102	/* start_compress done, write_raw_data OK */
+#define CSTATE_WRCOEFS	103	/* jpeg_write_coefficients done */
+#define DSTATE_START	200	/* after create_decompress */
+#define DSTATE_INHEADER	201	/* reading header markers, no SOS yet */
+#define DSTATE_READY	202	/* found SOS, ready for start_decompress */
+#define DSTATE_PRELOAD	203	/* reading multiscan file in start_decompress*/
+#define DSTATE_PRESCAN	204	/* performing dummy pass for 2-pass quant */
+#define DSTATE_SCANNING	205	/* start_decompress done, read_scanlines OK */
+#define DSTATE_RAW_OK	206	/* start_decompress done, read_raw_data OK */
+#define DSTATE_BUFIMAGE	207	/* expecting jpeg_start_output */
+#define DSTATE_BUFPOST	208	/* looking for SOS/EOI in jpeg_finish_output */
+#define DSTATE_RDCOEFS	209	/* reading file in jpeg_read_coefficients */
+#define DSTATE_STOPPING	210	/* looking for EOI in jpeg_finish_decompress */
+
+
+/* Declarations for compression modules */
+
+/* Master control module */
+struct jpeg_comp_master {
+  JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo));
+  JMETHOD(void, pass_startup, (j_compress_ptr cinfo));
+  JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
+
+  /* State variables made visible to other modules */
+  boolean call_pass_startup;	/* True if pass_startup must be called */
+  boolean is_last_pass;		/* True during last pass */
+};
+
+/* Main buffer control (downsampled-data buffer) */
+struct jpeg_c_main_controller {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(void, process_data, (j_compress_ptr cinfo,
+			       JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
+			       JDIMENSION in_rows_avail));
+};
+
+/* Compression preprocessing (downsampling input buffer control) */
+struct jpeg_c_prep_controller {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(void, pre_process_data, (j_compress_ptr cinfo,
+				   JSAMPARRAY input_buf,
+				   JDIMENSION *in_row_ctr,
+				   JDIMENSION in_rows_avail,
+				   JSAMPIMAGE output_buf,
+				   JDIMENSION *out_row_group_ctr,
+				   JDIMENSION out_row_groups_avail));
+};
+
+/* Coefficient buffer control */
+struct jpeg_c_coef_controller {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(boolean, compress_data, (j_compress_ptr cinfo,
+				   JSAMPIMAGE input_buf));
+};
+
+/* Colorspace conversion */
+struct jpeg_color_converter {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo));
+  JMETHOD(void, color_convert, (j_compress_ptr cinfo,
+				JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+				JDIMENSION output_row, int num_rows));
+};
+
+/* Downsampling */
+struct jpeg_downsampler {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo));
+  JMETHOD(void, downsample, (j_compress_ptr cinfo,
+			     JSAMPIMAGE input_buf, JDIMENSION in_row_index,
+			     JSAMPIMAGE output_buf,
+			     JDIMENSION out_row_group_index));
+
+  boolean need_context_rows;	/* TRUE if need rows above & below */
+};
+
+/* Forward DCT (also controls coefficient quantization) */
+typedef JMETHOD(void, forward_DCT_ptr,
+		(j_compress_ptr cinfo, jpeg_component_info * compptr,
+		 JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
+		 JDIMENSION start_row, JDIMENSION start_col,
+		 JDIMENSION num_blocks));
+
+struct jpeg_forward_dct {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo));
+  /* It is useful to allow each component to have a separate FDCT method. */
+  forward_DCT_ptr forward_DCT[MAX_COMPONENTS];
+};
+
+/* Entropy encoding */
+struct jpeg_entropy_encoder {
+  JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics));
+  JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKROW *MCU_data));
+  JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
+};
+
+/* Marker writing */
+struct jpeg_marker_writer {
+  JMETHOD(void, write_file_header, (j_compress_ptr cinfo));
+  JMETHOD(void, write_frame_header, (j_compress_ptr cinfo));
+  JMETHOD(void, write_scan_header, (j_compress_ptr cinfo));
+  JMETHOD(void, write_file_trailer, (j_compress_ptr cinfo));
+  JMETHOD(void, write_tables_only, (j_compress_ptr cinfo));
+  /* These routines are exported to allow insertion of extra markers */
+  /* Probably only COM and APPn markers should be written this way */
+  JMETHOD(void, write_marker_header, (j_compress_ptr cinfo, int marker,
+				      unsigned int datalen));
+  JMETHOD(void, write_marker_byte, (j_compress_ptr cinfo, int val));
+};
+
+
+/* Declarations for decompression modules */
+
+/* Master control module */
+struct jpeg_decomp_master {
+  JMETHOD(void, prepare_for_output_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, finish_output_pass, (j_decompress_ptr cinfo));
+
+  /* State variables made visible to other modules */
+  boolean is_dummy_pass;	/* True during 1st pass for 2-pass quant */
+};
+
+/* Input control module */
+struct jpeg_input_controller {
+  JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
+  JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
+  JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));
+
+  /* State variables made visible to other modules */
+  boolean has_multiple_scans;	/* True if file has multiple scans */
+  boolean eoi_reached;		/* True when EOI has been consumed */
+};
+
+/* Main buffer control (downsampled-data buffer) */
+struct jpeg_d_main_controller {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(void, process_data, (j_decompress_ptr cinfo,
+			       JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+			       JDIMENSION out_rows_avail));
+};
+
+/* Coefficient buffer control */
+struct jpeg_d_coef_controller {
+  JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
+  JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
+  JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
+  JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
+				 JSAMPIMAGE output_buf));
+  /* Pointer to array of coefficient virtual arrays, or NULL if none */
+  jvirt_barray_ptr *coef_arrays;
+};
+
+/* Decompression postprocessing (color quantization buffer control) */
+struct jpeg_d_post_controller {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
+  JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
+				    JSAMPIMAGE input_buf,
+				    JDIMENSION *in_row_group_ctr,
+				    JDIMENSION in_row_groups_avail,
+				    JSAMPARRAY output_buf,
+				    JDIMENSION *out_row_ctr,
+				    JDIMENSION out_rows_avail));
+};
+
+/* Marker reading & parsing */
+struct jpeg_marker_reader {
+  JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
+  /* Read markers until SOS or EOI.
+   * Returns same codes as are defined for jpeg_consume_input:
+   * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
+   */
+  JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
+  /* Read a restart marker --- exported for use by entropy decoder only */
+  jpeg_marker_parser_method read_restart_marker;
+
+  /* State of marker reader --- nominally internal, but applications
+   * supplying COM or APPn handlers might like to know the state.
+   */
+  boolean saw_SOI;		/* found SOI? */
+  boolean saw_SOF;		/* found SOF? */
+  int next_restart_num;		/* next restart number expected (0-7) */
+  unsigned int discarded_bytes;	/* # of bytes skipped looking for a marker */
+};
+
+/* Entropy decoding */
+struct jpeg_entropy_decoder {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
+  JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo,
+				JBLOCKROW *MCU_data));
+};
+
+/* Inverse DCT (also performs dequantization) */
+typedef JMETHOD(void, inverse_DCT_method_ptr,
+		(j_decompress_ptr cinfo, jpeg_component_info * compptr,
+		 JCOEFPTR coef_block,
+		 JSAMPARRAY output_buf, JDIMENSION output_col));
+
+struct jpeg_inverse_dct {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
+  /* It is useful to allow each component to have a separate IDCT method. */
+  inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
+};
+
+/* Upsampling (note that upsampler must also call color converter) */
+struct jpeg_upsampler {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, upsample, (j_decompress_ptr cinfo,
+			   JSAMPIMAGE input_buf,
+			   JDIMENSION *in_row_group_ctr,
+			   JDIMENSION in_row_groups_avail,
+			   JSAMPARRAY output_buf,
+			   JDIMENSION *out_row_ctr,
+			   JDIMENSION out_rows_avail));
+
+  boolean need_context_rows;	/* TRUE if need rows above & below */
+};
+
+/* Colorspace conversion */
+struct jpeg_color_deconverter {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
+				JSAMPIMAGE input_buf, JDIMENSION input_row,
+				JSAMPARRAY output_buf, int num_rows));
+};
+
+/* Color quantization or color precision reduction */
+struct jpeg_color_quantizer {
+  JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
+  JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
+				 JSAMPARRAY input_buf, JSAMPARRAY output_buf,
+				 int num_rows));
+  JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
+  JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
+};
+
+
+/* Miscellaneous useful macros */
+
+#undef MAX
+#define MAX(a,b)	((a) > (b) ? (a) : (b))
+#undef MIN
+#define MIN(a,b)	((a) < (b) ? (a) : (b))
+
+
+/* We assume that right shift corresponds to signed division by 2 with
+ * rounding towards minus infinity.  This is correct for typical "arithmetic
+ * shift" instructions that shift in copies of the sign bit.  But some
+ * C compilers implement >> with an unsigned shift.  For these machines you
+ * must define RIGHT_SHIFT_IS_UNSIGNED.
+ * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
+ * It is only applied with constant shift counts.  SHIFT_TEMPS must be
+ * included in the variables of any routine using RIGHT_SHIFT.
+ */
+
+#ifdef RIGHT_SHIFT_IS_UNSIGNED
+#define SHIFT_TEMPS	INT32 shift_temp;
+#define RIGHT_SHIFT(x,shft)  \
+	((shift_temp = (x)) < 0 ? \
+	 (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
+	 (shift_temp >> (shft)))
+#else
+#define SHIFT_TEMPS
+#define RIGHT_SHIFT(x,shft)	((x) >> (shft))
+#endif
+
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jinit_compress_master	jICompress
+#define jinit_c_master_control	jICMaster
+#define jinit_c_main_controller	jICMainC
+#define jinit_c_prep_controller	jICPrepC
+#define jinit_c_coef_controller	jICCoefC
+#define jinit_color_converter	jICColor
+#define jinit_downsampler	jIDownsampler
+#define jinit_forward_dct	jIFDCT
+#define jinit_huff_encoder	jIHEncoder
+#define jinit_arith_encoder	jIAEncoder
+#define jinit_marker_writer	jIMWriter
+#define jinit_master_decompress	jIDMaster
+#define jinit_d_main_controller	jIDMainC
+#define jinit_d_coef_controller	jIDCoefC
+#define jinit_d_post_controller	jIDPostC
+#define jinit_input_controller	jIInCtlr
+#define jinit_marker_reader	jIMReader
+#define jinit_huff_decoder	jIHDecoder
+#define jinit_arith_decoder	jIADecoder
+#define jinit_inverse_dct	jIIDCT
+#define jinit_upsampler		jIUpsampler
+#define jinit_color_deconverter	jIDColor
+#define jinit_1pass_quantizer	jI1Quant
+#define jinit_2pass_quantizer	jI2Quant
+#define jinit_merged_upsampler	jIMUpsampler
+#define jinit_memory_mgr	jIMemMgr
+#define jdiv_round_up		jDivRound
+#define jround_up		jRound
+#define jcopy_sample_rows	jCopySamples
+#define jcopy_block_row		jCopyBlocks
+#define jzero_far		jZeroFar
+#define jpeg_zigzag_order	jZIGTable
+#define jpeg_natural_order	jZAGTable
+#define jpeg_natural_order7	jZAGTable7
+#define jpeg_natural_order6	jZAGTable6
+#define jpeg_natural_order5	jZAGTable5
+#define jpeg_natural_order4	jZAGTable4
+#define jpeg_natural_order3	jZAGTable3
+#define jpeg_natural_order2	jZAGTable2
+#define jpeg_aritab		jAriTab
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+
+/* Compression module initialization routines */
+EXTERN(void) jinit_compress_master JPP((j_compress_ptr cinfo));
+EXTERN(void) jinit_c_master_control JPP((j_compress_ptr cinfo,
+					 boolean transcode_only));
+EXTERN(void) jinit_c_main_controller JPP((j_compress_ptr cinfo,
+					  boolean need_full_buffer));
+EXTERN(void) jinit_c_prep_controller JPP((j_compress_ptr cinfo,
+					  boolean need_full_buffer));
+EXTERN(void) jinit_c_coef_controller JPP((j_compress_ptr cinfo,
+					  boolean need_full_buffer));
+EXTERN(void) jinit_color_converter JPP((j_compress_ptr cinfo));
+EXTERN(void) jinit_downsampler JPP((j_compress_ptr cinfo));
+EXTERN(void) jinit_forward_dct JPP((j_compress_ptr cinfo));
+EXTERN(void) jinit_huff_encoder JPP((j_compress_ptr cinfo));
+EXTERN(void) jinit_arith_encoder JPP((j_compress_ptr cinfo));
+EXTERN(void) jinit_marker_writer JPP((j_compress_ptr cinfo));
+/* Decompression module initialization routines */
+EXTERN(void) jinit_master_decompress JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_d_main_controller JPP((j_decompress_ptr cinfo,
+					  boolean need_full_buffer));
+EXTERN(void) jinit_d_coef_controller JPP((j_decompress_ptr cinfo,
+					  boolean need_full_buffer));
+EXTERN(void) jinit_d_post_controller JPP((j_decompress_ptr cinfo,
+					  boolean need_full_buffer));
+EXTERN(void) jinit_input_controller JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_marker_reader JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_huff_decoder JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_arith_decoder JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_inverse_dct JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_upsampler JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_color_deconverter JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
+EXTERN(void) jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
+/* Memory manager initialization */
+EXTERN(void) jinit_memory_mgr JPP((j_common_ptr cinfo));
+
+/* Utility routines in jutils.c */
+EXTERN(long) jdiv_round_up JPP((long a, long b));
+EXTERN(long) jround_up JPP((long a, long b));
+EXTERN(void) jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
+				    JSAMPARRAY output_array, int dest_row,
+				    int num_rows, JDIMENSION num_cols));
+EXTERN(void) jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
+				  JDIMENSION num_blocks));
+EXTERN(void) jzero_far JPP((void FAR * target, size_t bytestozero));
+/* Constant tables in jutils.c */
+#if 0				/* This table is not actually needed in v6a */
+extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
+#endif
+extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
+extern const int jpeg_natural_order7[]; /* zz to natural order for 7x7 block */
+extern const int jpeg_natural_order6[]; /* zz to natural order for 6x6 block */
+extern const int jpeg_natural_order5[]; /* zz to natural order for 5x5 block */
+extern const int jpeg_natural_order4[]; /* zz to natural order for 4x4 block */
+extern const int jpeg_natural_order3[]; /* zz to natural order for 3x3 block */
+extern const int jpeg_natural_order2[]; /* zz to natural order for 2x2 block */
+
+/* Arithmetic coding probability estimation tables in jaricom.c */
+extern const INT32 jpeg_aritab[];
+
+/* Suppress undefined-structure complaints if necessary. */
+
+#ifdef INCOMPLETE_TYPES_BROKEN
+#ifndef AM_MEMORY_MANAGER	/* only jmemmgr.c defines these */
+struct jvirt_sarray_control { long dummy; };
+struct jvirt_barray_control { long dummy; };
+#endif
+#endif /* INCOMPLETE_TYPES_BROKEN */
+
+
+#else // JPEG_LIB_VERSION >= 80
+
 /*
  *
  * Copyright (C) 1991-1997, Thomas G. Lane. <tgl@netcom.com>
@@ -389,3 +807,5 @@ struct jvirt_sarray_control { long dummy; };
 struct jvirt_barray_control { long dummy; };
 #endif
 #endif /* INCOMPLETE_TYPES_BROKEN */
+
+#endif // JPEG_LIB_VERSION >= 80
diff --git a/digikam/libs/jpegutils/jpegutils.cpp b/digikam/libs/jpegutils/jpegutils.cpp
index b83825f8..44a89c4e 100644
--- a/digikam/libs/jpegutils/jpegutils.cpp
+++ b/digikam/libs/jpegutils/jpegutils.cpp
@@ -267,6 +267,7 @@ bool exifRotate(const TQString& file, const TQString& documentName)
         
         JCOPY_OPTION copyoption = JCOPYOPT_ALL;
         jpeg_transform_info transformoption;
+        memset(&transformoption, 0, sizeof(jpeg_transform_info));
     
         transformoption.force_grayscale = false;
         transformoption.trim            = false;
diff --git a/digikam/libs/jpegutils/transupp.cpp b/digikam/libs/jpegutils/transupp.cpp
index 1b586424..43fe36c4 100644
--- a/digikam/libs/jpegutils/transupp.cpp
+++ b/digikam/libs/jpegutils/transupp.cpp
@@ -1,7 +1,22 @@
+/* Although this file really shouldn't have access to the library internals,
+ * it's helpful to let it call jround_up() and jcopy_block_row().
+ */
+#define JPEG_INTERNALS
+
+// LibJPEG includes.
+
+extern "C"
+{
+#include "jinclude.h"
+#include "jpeglib.h"
+}
+
+#if JPEG_LIB_VERSION >= 80
+
 /*
  * transupp.c
  *
- * Copyright (C) 1997, Thomas G. Lane. <tgl@netcom.com>
+ * Copyright (C) 1997-2009, Thomas G. Lane, Guido Vollbeding.
  * This file is part of the Independent JPEG Group's software.
  * For conditions of distribution and use, see the accompanying README file.
  *
@@ -12,19 +27,1589 @@
  * interfaces.
  */
 
-/* Although this file really shouldn't have access to the library internals,
- * it's helpful to let it call jround_up() and jcopy_block_row().
+#include "transupp.h"         /* My own external interface */
+#include <ctype.h>            /* to declare isdigit() */
+
+namespace Digikam
+{
+
+#if TRANSFORMS_SUPPORTED
+
+/*
+ * Lossless image transformation routines.  These routines work on DCT
+ * coefficient arrays and thus do not require any lossy decompression
+ * or recompression of the image.
+ * Thanks to Guido Vollbeding for the initial design and code of this feature,
+ * and to Ben Jackson for introducing the cropping feature.
+ *
+ * Horizontal flipping is done in-place, using a single top-to-bottom
+ * pass through the virtual source array.  It will thus be much the
+ * fastest option for images larger than main memory.
+ *
+ * The other routines require a set of destination virtual arrays, so they
+ * need twice as much memory as jpegtran normally does.  The destination
+ * arrays are always written in normal scan order (top to bottom) because
+ * the virtual array manager expects this.  The source arrays will be scanned
+ * in the corresponding order, which means multiple passes through the source
+ * arrays for most of the transforms.  That could result in much thrashing
+ * if the image is larger than main memory.
+ *
+ * If cropping or trimming is involved, the destination arrays may be smaller
+ * than the source arrays.  Note it is not possible to do horizontal flip
+ * in-place when a nonzero Y crop offset is specified, since we'd have to move
+ * data from one block row to another but the virtual array manager doesn't
+ * guarantee we can touch more than one row at a time.  So in that case,
+ * we have to use a separate destination array.
+ *
+ * Some notes about the operating environment of the individual transform
+ * routines:
+ * 1. Both the source and destination virtual arrays are allocated from the
+ *    source JPEG object, and therefore should be manipulated by calling the
+ *    source's memory manager.
+ * 2. The destination's component count should be used.  It may be smaller
+ *    than the source's when forcing to grayscale.
+ * 3. Likewise the destination's sampling factors should be used.  When
+ *    forcing to grayscale the destination's sampling factors will be all 1,
+ *    and we may as well take that as the effective iMCU size.
+ * 4. When "trim" is in effect, the destination's dimensions will be the
+ *    trimmed values but the source's will be untrimmed.
+ * 5. When "crop" is in effect, the destination's dimensions will be the
+ *    cropped values but the source's will be uncropped.  Each transform
+ *    routine is responsible for picking up source data starting at the
+ *    correct X and Y offset for the crop region.  (The X and Y offsets
+ *    passed to the transform routines are measured in iMCU blocks of the
+ *    destination.)
+ * 6. All the routines assume that the source and destination buffers are
+ *    padded out to a full iMCU boundary.  This is true, although for the
+ *    source buffer it is an undocumented property of jdcoefct.c.
  */
-#define JPEG_INTERNALS
 
-// LibJPEG includes.
 
-extern "C"
+LOCAL(void)
+do_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+       JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+       jvirt_barray_ptr *src_coef_arrays,
+       jvirt_barray_ptr *dst_coef_arrays)
+/* Crop.  This is only used when no rotate/flip is requested with the crop. */
 {
-#include "jinclude.h"
-#include "jpeglib.h"
+  JDIMENSION dst_blk_y, x_crop_blocks, y_crop_blocks;
+  int ci, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  jpeg_component_info *compptr;
+
+  /* We simply have to copy the right amount of data (the destination's
+   * image size) starting at the given X and Y offsets in the source.
+   */
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+       dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      src_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+       dst_blk_y + y_crop_blocks,
+       (JDIMENSION) compptr->v_samp_factor, FALSE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
+                  dst_buffer[offset_y],
+                  compptr->width_in_blocks);
+      }
+    }
+  }
 }
 
+
+LOCAL(void)
+do_flip_h_no_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+               JDIMENSION x_crop_offset,
+               jvirt_barray_ptr *src_coef_arrays)
+/* Horizontal flip; done in-place, so no separate dest array is required.
+ * NB: this only works when y_crop_offset is zero.
+ */
+{
+  JDIMENSION MCU_cols, comp_width, blk_x, blk_y, x_crop_blocks;
+  int ci, k, offset_y;
+  JBLOCKARRAY buffer;
+  JCOEFPTR ptr1, ptr2;
+  JCOEF temp1, temp2;
+  jpeg_component_info *compptr;
+
+  /* Horizontal mirroring of DCT blocks is accomplished by swapping
+   * pairs of blocks in-place.  Within a DCT block, we perform horizontal
+   * mirroring by changing the signs of odd-numbered columns.
+   * Partial iMCUs at the right edge are left untouched.
+   */
+  MCU_cols = srcinfo->output_width /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    comp_width = MCU_cols * compptr->h_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    for (blk_y = 0; blk_y < compptr->height_in_blocks;
+       blk_y += compptr->v_samp_factor) {
+      buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      /* Do the mirroring */
+      for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
+        ptr1 = buffer[offset_y][blk_x];
+        ptr2 = buffer[offset_y][comp_width - blk_x - 1];
+        /* this unrolled loop doesn't need to know which row it's on... */
+        for (k = 0; k < DCTSIZE2; k += 2) {
+          temp1 = *ptr1;      /* swap even column */
+          temp2 = *ptr2;
+          *ptr1++ = temp2;
+          *ptr2++ = temp1;
+          temp1 = *ptr1;      /* swap odd column with sign change */
+          temp2 = *ptr2;
+          *ptr1++ = -temp2;
+          *ptr2++ = -temp1;
+        }
+      }
+      if (x_crop_blocks > 0) {
+        /* Now left-justify the portion of the data to be kept.
+         * We can't use a single jcopy_block_row() call because that routine
+         * depends on memcpy(), whose behavior is unspecified for overlapping
+         * source and destination areas.  Sigh.
+         */
+        for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
+          jcopy_block_row(buffer[offset_y] + blk_x + x_crop_blocks,
+                      buffer[offset_y] + blk_x,
+                      (JDIMENSION) 1);
+        }
+      }
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+         JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+         jvirt_barray_ptr *src_coef_arrays,
+         jvirt_barray_ptr *dst_coef_arrays)
+/* Horizontal flip in general cropping case */
+{
+  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
+  int ci, k, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  JBLOCKROW src_row_ptr, dst_row_ptr;
+  JCOEFPTR src_ptr, dst_ptr;
+  jpeg_component_info *compptr;
+
+  /* Here we must output into a separate array because we can't touch
+   * different rows of a single virtual array simultaneously.  Otherwise,
+   * this is essentially the same as the routine above.
+   */
+  MCU_cols = srcinfo->output_width /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    comp_width = MCU_cols * compptr->h_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+       dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      src_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+       dst_blk_y + y_crop_blocks,
+       (JDIMENSION) compptr->v_samp_factor, FALSE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      dst_row_ptr = dst_buffer[offset_y];
+      src_row_ptr = src_buffer[offset_y];
+      for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
+        if (x_crop_blocks + dst_blk_x < comp_width) {
+          /* Do the mirrorable blocks */
+          dst_ptr = dst_row_ptr[dst_blk_x];
+          src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
+          /* this unrolled loop doesn't need to know which row it's on... */
+          for (k = 0; k < DCTSIZE2; k += 2) {
+            *dst_ptr++ = *src_ptr++;       /* copy even column */
+            *dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
+          }
+        } else {
+          /* Copy last partial block(s) verbatim */
+          jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
+                      dst_row_ptr + dst_blk_x,
+                      (JDIMENSION) 1);
+        }
+      }
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+         JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+         jvirt_barray_ptr *src_coef_arrays,
+         jvirt_barray_ptr *dst_coef_arrays)
+/* Vertical flip */
+{
+  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
+  int ci, i, j, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  JBLOCKROW src_row_ptr, dst_row_ptr;
+  JCOEFPTR src_ptr, dst_ptr;
+  jpeg_component_info *compptr;
+
+  /* We output into a separate array because we can't touch different
+   * rows of the source virtual array simultaneously.  Otherwise, this
+   * is a pretty straightforward analog of horizontal flip.
+   * Within a DCT block, vertical mirroring is done by changing the signs
+   * of odd-numbered rows.
+   * Partial iMCUs at the bottom edge are copied verbatim.
+   */
+  MCU_rows = srcinfo->output_height /
+    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
+
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    comp_height = MCU_rows * compptr->v_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+       dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      if (y_crop_blocks + dst_blk_y < comp_height) {
+      /* Row is within the mirrorable area. */
+      src_buffer = (*srcinfo->mem->access_virt_barray)
+        ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+         comp_height - y_crop_blocks - dst_blk_y -
+         (JDIMENSION) compptr->v_samp_factor,
+         (JDIMENSION) compptr->v_samp_factor, FALSE);
+      } else {
+      /* Bottom-edge blocks will be copied verbatim. */
+      src_buffer = (*srcinfo->mem->access_virt_barray)
+        ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+         dst_blk_y + y_crop_blocks,
+         (JDIMENSION) compptr->v_samp_factor, FALSE);
+      }
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      if (y_crop_blocks + dst_blk_y < comp_height) {
+        /* Row is within the mirrorable area. */
+        dst_row_ptr = dst_buffer[offset_y];
+        src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
+        src_row_ptr += x_crop_blocks;
+        for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+             dst_blk_x++) {
+          dst_ptr = dst_row_ptr[dst_blk_x];
+          src_ptr = src_row_ptr[dst_blk_x];
+          for (i = 0; i < DCTSIZE; i += 2) {
+            /* copy even row */
+            for (j = 0; j < DCTSIZE; j++)
+            *dst_ptr++ = *src_ptr++;
+            /* copy odd row with sign change */
+            for (j = 0; j < DCTSIZE; j++)
+            *dst_ptr++ = - *src_ptr++;
+          }
+        }
+      } else {
+        /* Just copy row verbatim. */
+        jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
+                    dst_buffer[offset_y],
+                    compptr->width_in_blocks);
+      }
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+            JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+            jvirt_barray_ptr *src_coef_arrays,
+            jvirt_barray_ptr *dst_coef_arrays)
+/* Transpose source into destination */
+{
+  JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;
+  int ci, i, j, offset_x, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  JCOEFPTR src_ptr, dst_ptr;
+  jpeg_component_info *compptr;
+
+  /* Transposing pixels within a block just requires transposing the
+   * DCT coefficients.
+   * Partial iMCUs at the edges require no special treatment; we simply
+   * process all the available DCT blocks for every component.
+   */
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+       dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+           dst_blk_x += compptr->h_samp_factor) {
+        src_buffer = (*srcinfo->mem->access_virt_barray)
+          ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+           dst_blk_x + x_crop_blocks,
+           (JDIMENSION) compptr->h_samp_factor, FALSE);
+        for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+          dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+          src_ptr = src_buffer[offset_x][dst_blk_y + offset_y + y_crop_blocks];
+          for (i = 0; i < DCTSIZE; i++)
+            for (j = 0; j < DCTSIZE; j++)
+            dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+        }
+      }
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+         JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+         jvirt_barray_ptr *src_coef_arrays,
+         jvirt_barray_ptr *dst_coef_arrays)
+/* 90 degree rotation is equivalent to
+ *   1. Transposing the image;
+ *   2. Horizontal mirroring.
+ * These two steps are merged into a single processing routine.
+ */
+{
+  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
+  int ci, i, j, offset_x, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  JCOEFPTR src_ptr, dst_ptr;
+  jpeg_component_info *compptr;
+
+  /* Because of the horizontal mirror step, we can't process partial iMCUs
+   * at the (output) right edge properly.  They just get transposed and
+   * not mirrored.
+   */
+  MCU_cols = srcinfo->output_height /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    comp_width = MCU_cols * compptr->h_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+       dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+           dst_blk_x += compptr->h_samp_factor) {
+        if (x_crop_blocks + dst_blk_x < comp_width) {
+          /* Block is within the mirrorable area. */
+          src_buffer = (*srcinfo->mem->access_virt_barray)
+            ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+             comp_width - x_crop_blocks - dst_blk_x -
+             (JDIMENSION) compptr->h_samp_factor,
+             (JDIMENSION) compptr->h_samp_factor, FALSE);
+        } else {
+          /* Edge blocks are transposed but not mirrored. */
+          src_buffer = (*srcinfo->mem->access_virt_barray)
+            ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+             dst_blk_x + x_crop_blocks,
+             (JDIMENSION) compptr->h_samp_factor, FALSE);
+        }
+        for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+          dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+          if (x_crop_blocks + dst_blk_x < comp_width) {
+            /* Block is within the mirrorable area. */
+            src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
+            [dst_blk_y + offset_y + y_crop_blocks];
+            for (i = 0; i < DCTSIZE; i++) {
+            for (j = 0; j < DCTSIZE; j++)
+              dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+            i++;
+            for (j = 0; j < DCTSIZE; j++)
+              dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+            }
+          } else {
+            /* Edge blocks are transposed but not mirrored. */
+            src_ptr = src_buffer[offset_x]
+            [dst_blk_y + offset_y + y_crop_blocks];
+            for (i = 0; i < DCTSIZE; i++)
+            for (j = 0; j < DCTSIZE; j++)
+              dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+          }
+        }
+      }
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+          JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+          jvirt_barray_ptr *src_coef_arrays,
+          jvirt_barray_ptr *dst_coef_arrays)
+/* 270 degree rotation is equivalent to
+ *   1. Horizontal mirroring;
+ *   2. Transposing the image.
+ * These two steps are merged into a single processing routine.
+ */
+{
+  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
+  int ci, i, j, offset_x, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  JCOEFPTR src_ptr, dst_ptr;
+  jpeg_component_info *compptr;
+
+  /* Because of the horizontal mirror step, we can't process partial iMCUs
+   * at the (output) bottom edge properly.  They just get transposed and
+   * not mirrored.
+   */
+  MCU_rows = srcinfo->output_width /
+    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
+
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    comp_height = MCU_rows * compptr->v_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+       dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+           dst_blk_x += compptr->h_samp_factor) {
+        src_buffer = (*srcinfo->mem->access_virt_barray)
+          ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+           dst_blk_x + x_crop_blocks,
+           (JDIMENSION) compptr->h_samp_factor, FALSE);
+        for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+          dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+          if (y_crop_blocks + dst_blk_y < comp_height) {
+            /* Block is within the mirrorable area. */
+            src_ptr = src_buffer[offset_x]
+            [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
+            for (i = 0; i < DCTSIZE; i++) {
+            for (j = 0; j < DCTSIZE; j++) {
+              dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+              j++;
+              dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+            }
+            }
+          } else {
+            /* Edge blocks are transposed but not mirrored. */
+            src_ptr = src_buffer[offset_x]
+            [dst_blk_y + offset_y + y_crop_blocks];
+            for (i = 0; i < DCTSIZE; i++)
+            for (j = 0; j < DCTSIZE; j++)
+              dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+          }
+        }
+      }
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+          JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+          jvirt_barray_ptr *src_coef_arrays,
+          jvirt_barray_ptr *dst_coef_arrays)
+/* 180 degree rotation is equivalent to
+ *   1. Vertical mirroring;
+ *   2. Horizontal mirroring.
+ * These two steps are merged into a single processing routine.
+ */
+{
+  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
+  int ci, i, j, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  JBLOCKROW src_row_ptr, dst_row_ptr;
+  JCOEFPTR src_ptr, dst_ptr;
+  jpeg_component_info *compptr;
+
+  MCU_cols = srcinfo->output_width /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+  MCU_rows = srcinfo->output_height /
+    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
+
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    comp_width = MCU_cols * compptr->h_samp_factor;
+    comp_height = MCU_rows * compptr->v_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+       dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      if (y_crop_blocks + dst_blk_y < comp_height) {
+      /* Row is within the vertically mirrorable area. */
+      src_buffer = (*srcinfo->mem->access_virt_barray)
+        ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+         comp_height - y_crop_blocks - dst_blk_y -
+         (JDIMENSION) compptr->v_samp_factor,
+         (JDIMENSION) compptr->v_samp_factor, FALSE);
+      } else {
+      /* Bottom-edge rows are only mirrored horizontally. */
+      src_buffer = (*srcinfo->mem->access_virt_barray)
+        ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+         dst_blk_y + y_crop_blocks,
+         (JDIMENSION) compptr->v_samp_factor, FALSE);
+      }
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      dst_row_ptr = dst_buffer[offset_y];
+      if (y_crop_blocks + dst_blk_y < comp_height) {
+        /* Row is within the mirrorable area. */
+        src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
+        for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
+          dst_ptr = dst_row_ptr[dst_blk_x];
+          if (x_crop_blocks + dst_blk_x < comp_width) {
+            /* Process the blocks that can be mirrored both ways. */
+            src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
+            for (i = 0; i < DCTSIZE; i += 2) {
+            /* For even row, negate every odd column. */
+            for (j = 0; j < DCTSIZE; j += 2) {
+              *dst_ptr++ = *src_ptr++;
+              *dst_ptr++ = - *src_ptr++;
+            }
+            /* For odd row, negate every even column. */
+            for (j = 0; j < DCTSIZE; j += 2) {
+              *dst_ptr++ = - *src_ptr++;
+              *dst_ptr++ = *src_ptr++;
+            }
+            }
+          } else {
+            /* Any remaining right-edge blocks are only mirrored vertically. */
+            src_ptr = src_row_ptr[x_crop_blocks + dst_blk_x];
+            for (i = 0; i < DCTSIZE; i += 2) {
+            for (j = 0; j < DCTSIZE; j++)
+              *dst_ptr++ = *src_ptr++;
+            for (j = 0; j < DCTSIZE; j++)
+              *dst_ptr++ = - *src_ptr++;
+            }
+          }
+        }
+      } else {
+        /* Remaining rows are just mirrored horizontally. */
+        src_row_ptr = src_buffer[offset_y];
+        for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
+          if (x_crop_blocks + dst_blk_x < comp_width) {
+            /* Process the blocks that can be mirrored. */
+            dst_ptr = dst_row_ptr[dst_blk_x];
+            src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
+            for (i = 0; i < DCTSIZE2; i += 2) {
+            *dst_ptr++ = *src_ptr++;
+            *dst_ptr++ = - *src_ptr++;
+            }
+          } else {
+            /* Any remaining right-edge blocks are only copied. */
+            jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
+                        dst_row_ptr + dst_blk_x,
+                        (JDIMENSION) 1);
+          }
+        }
+      }
+      }
+    }
+  }
+}
+
+
+LOCAL(void)
+do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+             JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+             jvirt_barray_ptr *src_coef_arrays,
+             jvirt_barray_ptr *dst_coef_arrays)
+/* Transverse transpose is equivalent to
+ *   1. 180 degree rotation;
+ *   2. Transposition;
+ * or
+ *   1. Horizontal mirroring;
+ *   2. Transposition;
+ *   3. Horizontal mirroring.
+ * These steps are merged into a single processing routine.
+ */
+{
+  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
+  JDIMENSION x_crop_blocks, y_crop_blocks;
+  int ci, i, j, offset_x, offset_y;
+  JBLOCKARRAY src_buffer, dst_buffer;
+  JCOEFPTR src_ptr, dst_ptr;
+  jpeg_component_info *compptr;
+
+  MCU_cols = srcinfo->output_height /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+  MCU_rows = srcinfo->output_width /
+    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
+
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    comp_width = MCU_cols * compptr->h_samp_factor;
+    comp_height = MCU_rows * compptr->v_samp_factor;
+    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
+    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
+    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+       dst_blk_y += compptr->v_samp_factor) {
+      dst_buffer = (*srcinfo->mem->access_virt_barray)
+      ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+      for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+           dst_blk_x += compptr->h_samp_factor) {
+        if (x_crop_blocks + dst_blk_x < comp_width) {
+          /* Block is within the mirrorable area. */
+          src_buffer = (*srcinfo->mem->access_virt_barray)
+            ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+             comp_width - x_crop_blocks - dst_blk_x -
+             (JDIMENSION) compptr->h_samp_factor,
+             (JDIMENSION) compptr->h_samp_factor, FALSE);
+        } else {
+          src_buffer = (*srcinfo->mem->access_virt_barray)
+            ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+             dst_blk_x + x_crop_blocks,
+             (JDIMENSION) compptr->h_samp_factor, FALSE);
+        }
+        for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+          dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+          if (y_crop_blocks + dst_blk_y < comp_height) {
+            if (x_crop_blocks + dst_blk_x < comp_width) {
+            /* Block is within the mirrorable area. */
+            src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
+              [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
+            for (i = 0; i < DCTSIZE; i++) {
+              for (j = 0; j < DCTSIZE; j++) {
+                dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+                j++;
+                dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+              }
+              i++;
+              for (j = 0; j < DCTSIZE; j++) {
+                dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+                j++;
+                dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+              }
+            }
+            } else {
+            /* Right-edge blocks are mirrored in y only */
+            src_ptr = src_buffer[offset_x]
+              [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
+            for (i = 0; i < DCTSIZE; i++) {
+              for (j = 0; j < DCTSIZE; j++) {
+                dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+                j++;
+                dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+              }
+            }
+            }
+          } else {
+            if (x_crop_blocks + dst_blk_x < comp_width) {
+            /* Bottom-edge blocks are mirrored in x only */
+            src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
+              [dst_blk_y + offset_y + y_crop_blocks];
+            for (i = 0; i < DCTSIZE; i++) {
+              for (j = 0; j < DCTSIZE; j++)
+                dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+              i++;
+              for (j = 0; j < DCTSIZE; j++)
+                dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+            }
+            } else {
+            /* At lower right corner, just transpose, no mirroring */
+            src_ptr = src_buffer[offset_x]
+              [dst_blk_y + offset_y + y_crop_blocks];
+            for (i = 0; i < DCTSIZE; i++)
+              for (j = 0; j < DCTSIZE; j++)
+                dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+            }
+          }
+        }
+      }
+      }
+    }
+  }
+}
+
+
+/* Parse an unsigned integer: subroutine for jtransform_parse_crop_spec.
+ * Returns TRUE if valid integer found, FALSE if not.
+ * *strptr is advanced over the digit string, and *result is set to its value.
+ */
+
+LOCAL(boolean)
+jt_read_integer (const char ** strptr, JDIMENSION * result)
+{
+  const char * ptr = *strptr;
+  JDIMENSION val = 0;
+
+  for (; isdigit(*ptr); ptr++) {
+    val = val * 10 + (JDIMENSION) (*ptr - '0');
+  }
+  *result = val;
+  if (ptr == *strptr)
+    return FALSE;       /* oops, no digits */
+  *strptr = ptr;
+  return TRUE;
+}
+
+
+/* Parse a crop specification (written in X11 geometry style).
+ * The routine returns TRUE if the spec string is valid, FALSE if not.
+ *
+ * The crop spec string should have the format
+ *    <width>x<height>{+-}<xoffset>{+-}<yoffset>
+ * where width, height, xoffset, and yoffset are unsigned integers.
+ * Each of the elements can be omitted to indicate a default value.
+ * (A weakness of this style is that it is not possible to omit xoffset
+ * while specifying yoffset, since they look alike.)
+ *
+ * This code is loosely based on XParseGeometry from the X11 distribution.
+ */
+
+GLOBAL(boolean)
+jtransform_parse_crop_spec (jpeg_transform_info *info, const char *spec)
+{
+  info->crop = FALSE;
+  info->crop_width_set = JCROP_UNSET;
+  info->crop_height_set = JCROP_UNSET;
+  info->crop_xoffset_set = JCROP_UNSET;
+  info->crop_yoffset_set = JCROP_UNSET;
+
+  if (isdigit(*spec)) {
+    /* fetch width */
+    if (! jt_read_integer(&spec, &info->crop_width))
+      return FALSE;
+    info->crop_width_set = JCROP_POS;
+  }
+  if (*spec == 'x' || *spec == 'X') {     
+    /* fetch height */
+    spec++;
+    if (! jt_read_integer(&spec, &info->crop_height))
+      return FALSE;
+    info->crop_height_set = JCROP_POS;
+  }
+  if (*spec == '+' || *spec == '-') {
+    /* fetch xoffset */
+    info->crop_xoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
+    spec++;
+    if (! jt_read_integer(&spec, &info->crop_xoffset))
+      return FALSE;
+  }
+  if (*spec == '+' || *spec == '-') {
+    /* fetch yoffset */
+    info->crop_yoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
+    spec++;
+    if (! jt_read_integer(&spec, &info->crop_yoffset))
+      return FALSE;
+  }
+  /* We had better have gotten to the end of the string. */
+  if (*spec != '\0')
+    return FALSE;
+  info->crop = TRUE;
+  return TRUE;
+}
+
+
+/* Trim off any partial iMCUs on the indicated destination edge */
+
+LOCAL(void)
+trim_right_edge (jpeg_transform_info *info, JDIMENSION full_width)
+{
+  JDIMENSION MCU_cols;
+
+  MCU_cols = info->output_width / info->iMCU_sample_width;
+  if (MCU_cols > 0 && info->x_crop_offset + MCU_cols ==
+      full_width / info->iMCU_sample_width)
+    info->output_width = MCU_cols * info->iMCU_sample_width;
+}
+
+LOCAL(void)
+trim_bottom_edge (jpeg_transform_info *info, JDIMENSION full_height)
+{
+  JDIMENSION MCU_rows;
+
+  MCU_rows = info->output_height / info->iMCU_sample_height;
+  if (MCU_rows > 0 && info->y_crop_offset + MCU_rows ==
+      full_height / info->iMCU_sample_height)
+    info->output_height = MCU_rows * info->iMCU_sample_height;
+}
+
+
+/* Request any required workspace.
+ *
+ * This routine figures out the size that the output image will be
+ * (which implies that all the transform parameters must be set before
+ * it is called).
+ *
+ * We allocate the workspace virtual arrays from the source decompression
+ * object, so that all the arrays (both the original data and the workspace)
+ * will be taken into account while making memory management decisions.
+ * Hence, this routine must be called after jpeg_read_header (which reads
+ * the image dimensions) and before jpeg_read_coefficients (which realizes
+ * the source's virtual arrays).
+ *
+ * This function returns FALSE right away if -perfect is given
+ * and transformation is not perfect.  Otherwise returns TRUE.
+ */
+
+GLOBAL(boolean)
+jtransform_request_workspace (j_decompress_ptr srcinfo,
+                        jpeg_transform_info *info)
+{
+  jvirt_barray_ptr *coef_arrays;
+  boolean need_workspace, transpose_it;
+  jpeg_component_info *compptr;
+  JDIMENSION xoffset, yoffset;
+  JDIMENSION width_in_iMCUs, height_in_iMCUs;
+  JDIMENSION width_in_blocks, height_in_blocks;
+  int ci, h_samp_factor, v_samp_factor;
+
+  /* Determine number of components in output image */
+  if (info->force_grayscale &&
+      srcinfo->jpeg_color_space == JCS_YCbCr &&
+      srcinfo->num_components == 3)
+    /* We'll only process the first component */
+    info->num_components = 1;
+  else
+    /* Process all the components */
+    info->num_components = srcinfo->num_components;
+
+  /* Compute output image dimensions and related values. */
+  jpeg_core_output_dimensions(srcinfo);
+
+  /* Return right away if -perfect is given and transformation is not perfect.
+   */
+  if (info->perfect) {
+    if (info->num_components == 1) {
+      if (!jtransform_perfect_transform(srcinfo->output_width,
+        srcinfo->output_height,
+        srcinfo->min_DCT_h_scaled_size,
+        srcinfo->min_DCT_v_scaled_size,
+        info->transform))
+      return FALSE;
+    } else {
+      if (!jtransform_perfect_transform(srcinfo->output_width,
+        srcinfo->output_height,
+        srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size,
+        srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size,
+        info->transform))
+      return FALSE;
+    }
+  }
+
+  /* If there is only one output component, force the iMCU size to be 1;
+   * else use the source iMCU size.  (This allows us to do the right thing
+   * when reducing color to grayscale, and also provides a handy way of
+   * cleaning up "funny" grayscale images whose sampling factors are not 1x1.)
+   */
+  switch (info->transform) {
+  case JXFORM_TRANSPOSE:
+  case JXFORM_TRANSVERSE:
+  case JXFORM_ROT_90:
+  case JXFORM_ROT_270:
+    info->output_width = srcinfo->output_height;
+    info->output_height = srcinfo->output_width;
+    if (info->num_components == 1) {
+      info->iMCU_sample_width = srcinfo->min_DCT_v_scaled_size;
+      info->iMCU_sample_height = srcinfo->min_DCT_h_scaled_size;
+    } else {
+      info->iMCU_sample_width =
+      srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;
+      info->iMCU_sample_height =
+      srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;
+    }
+    break;
+  default:
+    info->output_width = srcinfo->output_width;
+    info->output_height = srcinfo->output_height;
+    if (info->num_components == 1) {
+      info->iMCU_sample_width = srcinfo->min_DCT_h_scaled_size;
+      info->iMCU_sample_height = srcinfo->min_DCT_v_scaled_size;
+    } else {
+      info->iMCU_sample_width =
+      srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;
+      info->iMCU_sample_height =
+      srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;
+    }
+    break;
+  }
+
+  /* If cropping has been requested, compute the crop area's position and
+   * dimensions, ensuring that its upper left corner falls at an iMCU boundary.
+   */
+  if (info->crop) {
+    /* Insert default values for unset crop parameters */
+    if (info->crop_xoffset_set == JCROP_UNSET)
+      info->crop_xoffset = 0; /* default to +0 */
+    if (info->crop_yoffset_set == JCROP_UNSET)
+      info->crop_yoffset = 0; /* default to +0 */
+    if (info->crop_xoffset >= info->output_width ||
+      info->crop_yoffset >= info->output_height)
+      ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+    if (info->crop_width_set == JCROP_UNSET)
+      info->crop_width = info->output_width - info->crop_xoffset;
+    if (info->crop_height_set == JCROP_UNSET)
+      info->crop_height = info->output_height - info->crop_yoffset;
+    /* Ensure parameters are valid */
+    if (info->crop_width <= 0 || info->crop_width > info->output_width ||
+      info->crop_height <= 0 || info->crop_height > info->output_height ||
+      info->crop_xoffset > info->output_width - info->crop_width ||
+      info->crop_yoffset > info->output_height - info->crop_height)
+      ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+    /* Convert negative crop offsets into regular offsets */
+    if (info->crop_xoffset_set == JCROP_NEG)
+      xoffset = info->output_width - info->crop_width - info->crop_xoffset;
+    else
+      xoffset = info->crop_xoffset;
+    if (info->crop_yoffset_set == JCROP_NEG)
+      yoffset = info->output_height - info->crop_height - info->crop_yoffset;
+    else
+      yoffset = info->crop_yoffset;
+    /* Now adjust so that upper left corner falls at an iMCU boundary */
+    info->output_width =
+      info->crop_width + (xoffset % info->iMCU_sample_width);
+    info->output_height =
+      info->crop_height + (yoffset % info->iMCU_sample_height);
+    /* Save x/y offsets measured in iMCUs */
+    info->x_crop_offset = xoffset / info->iMCU_sample_width;
+    info->y_crop_offset = yoffset / info->iMCU_sample_height;
+  } else {
+    info->x_crop_offset = 0;
+    info->y_crop_offset = 0;
+  }
+
+  /* Figure out whether we need workspace arrays,
+   * and if so whether they are transposed relative to the source.
+   */
+  need_workspace = FALSE;
+  transpose_it = FALSE;
+  switch (info->transform) {
+  case JXFORM_NONE:
+    if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
+      need_workspace = TRUE;
+    /* No workspace needed if neither cropping nor transforming */
+    break;
+  case JXFORM_FLIP_H:
+    if (info->trim)
+      trim_right_edge(info, srcinfo->output_width);
+    if (info->y_crop_offset != 0)
+      need_workspace = TRUE;
+    /* do_flip_h_no_crop doesn't need a workspace array */
+    break;
+  case JXFORM_FLIP_V:
+    if (info->trim)
+      trim_bottom_edge(info, srcinfo->output_height);
+    /* Need workspace arrays having same dimensions as source image. */
+    need_workspace = TRUE;
+    break;
+  case JXFORM_TRANSPOSE:
+    /* transpose does NOT have to trim anything */
+    /* Need workspace arrays having transposed dimensions. */
+    need_workspace = TRUE;
+    transpose_it = TRUE;
+    break;
+  case JXFORM_TRANSVERSE:
+    if (info->trim) {
+      trim_right_edge(info, srcinfo->output_height);
+      trim_bottom_edge(info, srcinfo->output_width);
+    }
+    /* Need workspace arrays having transposed dimensions. */
+    need_workspace = TRUE;
+    transpose_it = TRUE;
+    break;
+  case JXFORM_ROT_90:
+    if (info->trim)
+      trim_right_edge(info, srcinfo->output_height);
+    /* Need workspace arrays having transposed dimensions. */
+    need_workspace = TRUE;
+    transpose_it = TRUE;
+    break;
+  case JXFORM_ROT_180:
+    if (info->trim) {
+      trim_right_edge(info, srcinfo->output_width);
+      trim_bottom_edge(info, srcinfo->output_height);
+    }
+    /* Need workspace arrays having same dimensions as source image. */
+    need_workspace = TRUE;
+    break;
+  case JXFORM_ROT_270:
+    if (info->trim)
+      trim_bottom_edge(info, srcinfo->output_width);
+    /* Need workspace arrays having transposed dimensions. */
+    need_workspace = TRUE;
+    transpose_it = TRUE;
+    break;
+  }
+
+  /* Allocate workspace if needed.
+   * Note that we allocate arrays padded out to the next iMCU boundary,
+   * so that transform routines need not worry about missing edge blocks.
+   */
+  if (need_workspace) {
+    coef_arrays = (jvirt_barray_ptr *)
+      (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
+            SIZEOF(jvirt_barray_ptr) * info->num_components);
+    width_in_iMCUs = (JDIMENSION)
+      jdiv_round_up((long) info->output_width,
+                (long) info->iMCU_sample_width);
+    height_in_iMCUs = (JDIMENSION)
+      jdiv_round_up((long) info->output_height,
+                (long) info->iMCU_sample_height);
+    for (ci = 0; ci < info->num_components; ci++) {
+      compptr = srcinfo->comp_info + ci;
+      if (info->num_components == 1) {
+      /* we're going to force samp factors to 1x1 in this case */
+      h_samp_factor = v_samp_factor = 1;
+      } else if (transpose_it) {
+      h_samp_factor = compptr->v_samp_factor;
+      v_samp_factor = compptr->h_samp_factor;
+      } else {
+      h_samp_factor = compptr->h_samp_factor;
+      v_samp_factor = compptr->v_samp_factor;
+      }
+      width_in_blocks = width_in_iMCUs * h_samp_factor;
+      height_in_blocks = height_in_iMCUs * v_samp_factor;
+      coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
+      ((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
+       width_in_blocks, height_in_blocks, (JDIMENSION) v_samp_factor);
+    }
+    info->workspace_coef_arrays = coef_arrays;
+  } else
+    info->workspace_coef_arrays = NULL;
+
+  return TRUE;
+}
+
+
+/* Transpose destination image parameters */
+
+LOCAL(void)
+transpose_critical_parameters (j_compress_ptr dstinfo)
+{
+  int tblno, i, j, ci, itemp;
+  jpeg_component_info *compptr;
+  JQUANT_TBL *qtblptr;
+  JDIMENSION jtemp;
+  UINT16 qtemp;
+
+  /* Transpose image dimensions */
+  jtemp = dstinfo->image_width;
+  dstinfo->image_width = dstinfo->image_height;
+  dstinfo->image_height = jtemp;
+  itemp = dstinfo->min_DCT_h_scaled_size;
+  dstinfo->min_DCT_h_scaled_size = dstinfo->min_DCT_v_scaled_size;
+  dstinfo->min_DCT_v_scaled_size = itemp;
+
+  /* Transpose sampling factors */
+  for (ci = 0; ci < dstinfo->num_components; ci++) {
+    compptr = dstinfo->comp_info + ci;
+    itemp = compptr->h_samp_factor;
+    compptr->h_samp_factor = compptr->v_samp_factor;
+    compptr->v_samp_factor = itemp;
+  }
+
+  /* Transpose quantization tables */
+  for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
+    qtblptr = dstinfo->quant_tbl_ptrs[tblno];
+    if (qtblptr != NULL) {
+      for (i = 0; i < DCTSIZE; i++) {
+      for (j = 0; j < i; j++) {
+        qtemp = qtblptr->quantval[i*DCTSIZE+j];
+        qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];
+        qtblptr->quantval[j*DCTSIZE+i] = qtemp;
+      }
+      }
+    }
+  }
+}
+
+
+/* Adjust Exif image parameters.
+ *
+ * We try to adjust the Tags ExifImageWidth and ExifImageHeight if possible.
+ */
+
+LOCAL(void)
+adjust_exif_parameters (JOCTET FAR * data, unsigned int length,
+                  JDIMENSION new_width, JDIMENSION new_height)
+{
+  boolean is_motorola; /* Flag for byte order */
+  unsigned int number_of_tags, tagnum;
+  unsigned int firstoffset, offset;
+  JDIMENSION new_value;
+
+  if (length < 12) return; /* Length of an IFD entry */
+
+  /* Discover byte order */
+  if (GETJOCTET(data[0]) == 0x49 && GETJOCTET(data[1]) == 0x49)
+    is_motorola = FALSE;
+  else if (GETJOCTET(data[0]) == 0x4D && GETJOCTET(data[1]) == 0x4D)
+    is_motorola = TRUE;
+  else
+    return;
+
+  /* Check Tag Mark */
+  if (is_motorola) {
+    if (GETJOCTET(data[2]) != 0) return;
+    if (GETJOCTET(data[3]) != 0x2A) return;
+  } else {
+    if (GETJOCTET(data[3]) != 0) return;
+    if (GETJOCTET(data[2]) != 0x2A) return;
+  }
+
+  /* Get first IFD offset (offset to IFD0) */
+  if (is_motorola) {
+    if (GETJOCTET(data[4]) != 0) return;
+    if (GETJOCTET(data[5]) != 0) return;
+    firstoffset = GETJOCTET(data[6]);
+    firstoffset <<= 8;
+    firstoffset += GETJOCTET(data[7]);
+  } else {
+    if (GETJOCTET(data[7]) != 0) return;
+    if (GETJOCTET(data[6]) != 0) return;
+    firstoffset = GETJOCTET(data[5]);
+    firstoffset <<= 8;
+    firstoffset += GETJOCTET(data[4]);
+  }
+  if (firstoffset > length - 2) return; /* check end of data segment */
+
+  /* Get the number of directory entries contained in this IFD */
+  if (is_motorola) {
+    number_of_tags = GETJOCTET(data[firstoffset]);
+    number_of_tags <<= 8;
+    number_of_tags += GETJOCTET(data[firstoffset+1]);
+  } else {
+    number_of_tags = GETJOCTET(data[firstoffset+1]);
+    number_of_tags <<= 8;
+    number_of_tags += GETJOCTET(data[firstoffset]);
+  }
+  if (number_of_tags == 0) return;
+  firstoffset += 2;
+
+  /* Search for ExifSubIFD offset Tag in IFD0 */
+  for (;;) {
+    if (firstoffset > length - 12) return; /* check end of data segment */
+    /* Get Tag number */
+    if (is_motorola) {
+      tagnum = GETJOCTET(data[firstoffset]);
+      tagnum <<= 8;
+      tagnum += GETJOCTET(data[firstoffset+1]);
+    } else {
+      tagnum = GETJOCTET(data[firstoffset+1]);
+      tagnum <<= 8;
+      tagnum += GETJOCTET(data[firstoffset]);
+    }
+    if (tagnum == 0x8769) break; /* found ExifSubIFD offset Tag */
+    if (--number_of_tags == 0) return;
+    firstoffset += 12;
+  }
+
+  /* Get the ExifSubIFD offset */
+  if (is_motorola) {
+    if (GETJOCTET(data[firstoffset+8]) != 0) return;
+    if (GETJOCTET(data[firstoffset+9]) != 0) return;
+    offset = GETJOCTET(data[firstoffset+10]);
+    offset <<= 8;
+    offset += GETJOCTET(data[firstoffset+11]);
+  } else {
+    if (GETJOCTET(data[firstoffset+11]) != 0) return;
+    if (GETJOCTET(data[firstoffset+10]) != 0) return;
+    offset = GETJOCTET(data[firstoffset+9]);
+    offset <<= 8;
+    offset += GETJOCTET(data[firstoffset+8]);
+  }
+  if (offset > length - 2) return; /* check end of data segment */
+
+  /* Get the number of directory entries contained in this SubIFD */
+  if (is_motorola) {
+    number_of_tags = GETJOCTET(data[offset]);
+    number_of_tags <<= 8;
+    number_of_tags += GETJOCTET(data[offset+1]);
+  } else {
+    number_of_tags = GETJOCTET(data[offset+1]);
+    number_of_tags <<= 8;
+    number_of_tags += GETJOCTET(data[offset]);
+  }
+  if (number_of_tags < 2) return;
+  offset += 2;
+
+  /* Search for ExifImageWidth and ExifImageHeight Tags in this SubIFD */
+  do {
+    if (offset > length - 12) return; /* check end of data segment */
+    /* Get Tag number */
+    if (is_motorola) {
+      tagnum = GETJOCTET(data[offset]);
+      tagnum <<= 8;
+      tagnum += GETJOCTET(data[offset+1]);
+    } else {
+      tagnum = GETJOCTET(data[offset+1]);
+      tagnum <<= 8;
+      tagnum += GETJOCTET(data[offset]);
+    }
+    if (tagnum == 0xA002 || tagnum == 0xA003) {
+      if (tagnum == 0xA002)
+      new_value = new_width; /* ExifImageWidth Tag */
+      else
+      new_value = new_height; /* ExifImageHeight Tag */
+      if (is_motorola) {
+      data[offset+2] = 0; /* Format = unsigned long (4 octets) */
+      data[offset+3] = 4;
+      data[offset+4] = 0; /* Number Of Components = 1 */
+      data[offset+5] = 0;
+      data[offset+6] = 0;
+      data[offset+7] = 1;
+      data[offset+8] = 0;
+      data[offset+9] = 0;
+      data[offset+10] = (JOCTET)((new_value >> 8) & 0xFF);
+      data[offset+11] = (JOCTET)(new_value & 0xFF);
+      } else {
+      data[offset+2] = 4; /* Format = unsigned long (4 octets) */
+      data[offset+3] = 0;
+      data[offset+4] = 1; /* Number Of Components = 1 */
+      data[offset+5] = 0;
+      data[offset+6] = 0;
+      data[offset+7] = 0;
+      data[offset+8] = (JOCTET)(new_value & 0xFF);
+      data[offset+9] = (JOCTET)((new_value >> 8) & 0xFF);
+      data[offset+10] = 0;
+      data[offset+11] = 0;
+      }
+    }
+    offset += 12;
+  } while (--number_of_tags);
+}
+
+
+/* Adjust output image parameters as needed.
+ *
+ * This must be called after jpeg_copy_critical_parameters()
+ * and before jpeg_write_coefficients().
+ *
+ * The return value is the set of virtual coefficient arrays to be written
+ * (either the ones allocated by jtransform_request_workspace, or the
+ * original source data arrays).  The caller will need to pass this value
+ * to jpeg_write_coefficients().
+ */
+
+GLOBAL(jvirt_barray_ptr *)
+jtransform_adjust_parameters (j_decompress_ptr srcinfo,
+                        j_compress_ptr dstinfo,
+                        jvirt_barray_ptr *src_coef_arrays,
+                        jpeg_transform_info *info)
+{
+  /* If force-to-grayscale is requested, adjust destination parameters */
+  if (info->force_grayscale) {
+    /* First, ensure we have YCbCr or grayscale data, and that the source's
+     * Y channel is full resolution.  (No reasonable person would make Y
+     * be less than full resolution, so actually coping with that case
+     * isn't worth extra code space.  But we check it to avoid crashing.)
+     */
+    if (((dstinfo->jpeg_color_space == JCS_YCbCr &&
+        dstinfo->num_components == 3) ||
+       (dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
+        dstinfo->num_components == 1)) &&
+      srcinfo->comp_info[0].h_samp_factor == srcinfo->max_h_samp_factor &&
+      srcinfo->comp_info[0].v_samp_factor == srcinfo->max_v_samp_factor) {
+      /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
+       * properly.  Among other things, it sets the target h_samp_factor &
+       * v_samp_factor to 1, which typically won't match the source.
+       * We have to preserve the source's quantization table number, however.
+       */
+      int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
+      jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
+      dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
+    } else {
+      /* Sorry, can't do it */
+      ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
+    }
+  } else if (info->num_components == 1) {
+    /* For a single-component source, we force the destination sampling factors
+     * to 1x1, with or without force_grayscale.  This is useful because some
+     * decoders choke on grayscale images with other sampling factors.
+     */
+    dstinfo->comp_info[0].h_samp_factor = 1;
+    dstinfo->comp_info[0].v_samp_factor = 1;
+  }
+
+  /* Correct the destination's image dimensions as necessary
+   * for rotate/flip, resize, and crop operations.
+   */
+  dstinfo->jpeg_width = info->output_width;
+  dstinfo->jpeg_height = info->output_height;
+
+  /* Transpose destination image parameters */
+  switch (info->transform) {
+  case JXFORM_TRANSPOSE:
+  case JXFORM_TRANSVERSE:
+  case JXFORM_ROT_90:
+  case JXFORM_ROT_270:
+    transpose_critical_parameters(dstinfo);
+    break;
+  default:
+    break;
+  }
+
+  /* Adjust Exif properties */
+  if (srcinfo->marker_list != NULL &&
+      srcinfo->marker_list->marker == JPEG_APP0+1 &&
+      srcinfo->marker_list->data_length >= 6 &&
+      GETJOCTET(srcinfo->marker_list->data[0]) == 0x45 &&
+      GETJOCTET(srcinfo->marker_list->data[1]) == 0x78 &&
+      GETJOCTET(srcinfo->marker_list->data[2]) == 0x69 &&
+      GETJOCTET(srcinfo->marker_list->data[3]) == 0x66 &&
+      GETJOCTET(srcinfo->marker_list->data[4]) == 0 &&
+      GETJOCTET(srcinfo->marker_list->data[5]) == 0) {
+    /* Suppress output of JFIF marker */
+    dstinfo->write_JFIF_header = FALSE;
+    /* Adjust Exif image parameters */
+    if (dstinfo->jpeg_width != srcinfo->image_width ||
+      dstinfo->jpeg_height != srcinfo->image_height)
+      /* Align data segment to start of TIFF structure for parsing */
+      adjust_exif_parameters(srcinfo->marker_list->data + 6,
+      srcinfo->marker_list->data_length - 6,
+      dstinfo->jpeg_width, dstinfo->jpeg_height);
+  }
+
+  /* Return the appropriate output data set */
+  if (info->workspace_coef_arrays != NULL)
+    return info->workspace_coef_arrays;
+  return src_coef_arrays;
+}
+
+
+/* Execute the actual transformation, if any.
+ *
+ * This must be called *after* jpeg_write_coefficients, because it depends
+ * on jpeg_write_coefficients to have computed subsidiary values such as
+ * the per-component width and height fields in the destination object.
+ *
+ * Note that some transformations will modify the source data arrays!
+ */
+
+GLOBAL(void)
+jtransform_execute_transform (j_decompress_ptr srcinfo,
+                        j_compress_ptr dstinfo,
+                        jvirt_barray_ptr *src_coef_arrays,
+                        jpeg_transform_info *info)
+{
+  jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;
+
+  /* Note: conditions tested here should match those in switch statement
+   * in jtransform_request_workspace()
+   */
+  switch (info->transform) {
+  case JXFORM_NONE:
+    if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
+      do_crop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+            src_coef_arrays, dst_coef_arrays);
+    break;
+  case JXFORM_FLIP_H:
+    if (info->y_crop_offset != 0)
+      do_flip_h(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+            src_coef_arrays, dst_coef_arrays);
+    else
+      do_flip_h_no_crop(srcinfo, dstinfo, info->x_crop_offset,
+                  src_coef_arrays);
+    break;
+  case JXFORM_FLIP_V:
+    do_flip_v(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+            src_coef_arrays, dst_coef_arrays);
+    break;
+  case JXFORM_TRANSPOSE:
+    do_transpose(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+             src_coef_arrays, dst_coef_arrays);
+    break;
+  case JXFORM_TRANSVERSE:
+    do_transverse(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+              src_coef_arrays, dst_coef_arrays);
+    break;
+  case JXFORM_ROT_90:
+    do_rot_90(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+            src_coef_arrays, dst_coef_arrays);
+    break;
+  case JXFORM_ROT_180:
+    do_rot_180(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+             src_coef_arrays, dst_coef_arrays);
+    break;
+  case JXFORM_ROT_270:
+    do_rot_270(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+             src_coef_arrays, dst_coef_arrays);
+    break;
+  }
+}
+
+/* jtransform_perfect_transform
+ *
+ * Determine whether lossless transformation is perfectly
+ * possible for a specified image and transformation.
+ *
+ * Inputs:
+ *   image_width, image_height: source image dimensions.
+ *   MCU_width, MCU_height: pixel dimensions of MCU.
+ *   transform: transformation identifier.
+ * Parameter sources from initialized jpeg_struct
+ * (after reading source header):
+ *   image_width = cinfo.image_width
+ *   image_height = cinfo.image_height
+ *   MCU_width = cinfo.max_h_samp_factor * cinfo.block_size
+ *   MCU_height = cinfo.max_v_samp_factor * cinfo.block_size
+ * Result:
+ *   TRUE = perfect transformation possible
+ *   FALSE = perfect transformation not possible
+ *           (may use custom action then)
+ */
+
+GLOBAL(boolean)
+jtransform_perfect_transform(JDIMENSION image_width, JDIMENSION image_height,
+                       int MCU_width, int MCU_height,
+                       JXFORM_CODE transform)
+{
+  boolean result = TRUE; /* initialize TRUE */
+
+  switch (transform) {
+  case JXFORM_FLIP_H:
+  case JXFORM_ROT_270:
+    if (image_width % (JDIMENSION) MCU_width)
+      result = FALSE;
+    break;
+  case JXFORM_FLIP_V:
+  case JXFORM_ROT_90:
+    if (image_height % (JDIMENSION) MCU_height)
+      result = FALSE;
+    break;
+  case JXFORM_TRANSVERSE:
+  case JXFORM_ROT_180:
+    if (image_width % (JDIMENSION) MCU_width)
+      result = FALSE;
+    if (image_height % (JDIMENSION) MCU_height)
+      result = FALSE;
+    break;
+  default:
+    break;
+  }
+
+  return result;
+}
+
+#endif /* TRANSFORMS_SUPPORTED */
+
+
+/* Setup decompression object to save desired markers in memory.
+ * This must be called before jpeg_read_header() to have the desired effect.
+ */
+
+GLOBAL(void)
+jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)
+{
+#ifdef SAVE_MARKERS_SUPPORTED
+  int m;
+
+  /* Save comments except under NONE option */
+  if (option != JCOPYOPT_NONE) {
+    jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
+  }
+  /* Save all types of APPn markers iff ALL option */
+  if (option == JCOPYOPT_ALL) {
+    for (m = 0; m < 16; m++)
+      jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
+  }
+#endif /* SAVE_MARKERS_SUPPORTED */
+}
+
+/* Copy markers saved in the given source object to the destination object.
+ * This should be called just after jpeg_start_compress() or
+ * jpeg_write_coefficients().
+ * Note that those routines will have written the SOI, and also the
+ * JFIF APP0 or Adobe APP14 markers if selected.
+ */
+
+GLOBAL(void)
+jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+                   JCOPY_OPTION option)
+{
+  jpeg_saved_marker_ptr marker;
+
+  /* In the current implementation, we don't actually need to examine the
+   * option flag here; we just copy everything that got saved.
+   * But to avoid confusion, we do not output JFIF and Adobe APP14 markers
+   * if the encoder library already wrote one.
+   */
+  for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {
+    if (dstinfo->write_JFIF_header &&
+      marker->marker == JPEG_APP0 &&
+      marker->data_length >= 5 &&
+      GETJOCTET(marker->data[0]) == 0x4A &&
+      GETJOCTET(marker->data[1]) == 0x46 &&
+      GETJOCTET(marker->data[2]) == 0x49 &&
+      GETJOCTET(marker->data[3]) == 0x46 &&
+      GETJOCTET(marker->data[4]) == 0)
+      continue;               /* reject duplicate JFIF */
+    if (dstinfo->write_Adobe_marker &&
+      marker->marker == JPEG_APP0+14 &&
+      marker->data_length >= 5 &&
+      GETJOCTET(marker->data[0]) == 0x41 &&
+      GETJOCTET(marker->data[1]) == 0x64 &&
+      GETJOCTET(marker->data[2]) == 0x6F &&
+      GETJOCTET(marker->data[3]) == 0x62 &&
+      GETJOCTET(marker->data[4]) == 0x65)
+      continue;               /* reject duplicate Adobe */
+#ifdef NEED_FAR_POINTERS
+    /* We could use jpeg_write_marker if the data weren't FAR... */
+    {
+      unsigned int i;
+      jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);
+      for (i = 0; i < marker->data_length; i++)
+      jpeg_write_m_byte(dstinfo, marker->data[i]);
+    }
+#else
+    jpeg_write_marker(dstinfo, marker->marker,
+                  marker->data, marker->data_length);
+#endif
+  }
+}
+
+} // namespace Digikam
+
+#else // JPEG_LIB_VERSION >= 80
+
+/*
+ * transupp.c
+ *
+ * Copyright (C) 1997, Thomas G. Lane. <tgl@netcom.com>
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains image transformation routines and other utility code
+ * used by the jpegtran sample application.  These are NOT part of the core
+ * JPEG library.  But we keep these routines separate from jpegtran.c to
+ * ease the task of maintaining jpegtran-like programs that have other user
+ * interfaces.
+ */
+
 // Local includes.
 
 #include "transupp.h"		/* My own external interface */
@@ -938,3 +2523,5 @@ jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
 }
 
 } // namespace Digikam
+
+#endif // JPEG_LIB_VERSION >= 80
diff --git a/digikam/libs/jpegutils/transupp.h b/digikam/libs/jpegutils/transupp.h
index 637e0a17..7dd3fad6 100644
--- a/digikam/libs/jpegutils/transupp.h
+++ b/digikam/libs/jpegutils/transupp.h
@@ -1,3 +1,229 @@
+#if JPEG_LIB_VERSION >= 80
+
+/*
+ * transupp.h
+ *
+ * Copyright (C) 1997-2009, Thomas G. Lane, Guido Vollbeding.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains declarations for image transformation routines and
+ * other utility code used by the jpegtran sample application.  These are
+ * NOT part of the core JPEG library.  But we keep these routines separate
+ * from jpegtran.c to ease the task of maintaining jpegtran-like programs
+ * that have other user interfaces.
+ *
+ * NOTE: all the routines declared here have very specific requirements
+ * about when they are to be executed during the reading and writing of the
+ * source and destination files.  See the comments in transupp.c, or see
+ * jpegtran.c for an example of correct usage.
+ */
+
+#ifndef TRANSUPP_H
+#define TRANSUPP_H
+
+namespace Digikam
+{
+
+/* If you happen not to want the image transform support, disable it here */
+#ifndef TRANSFORMS_SUPPORTED
+#define TRANSFORMS_SUPPORTED 1            /* 0 disables transform code */
+#endif
+
+/*
+ * Although rotating and flipping data expressed as DCT coefficients is not
+ * hard, there is an asymmetry in the JPEG format specification for images
+ * whose dimensions aren't multiples of the iMCU size.  The right and bottom
+ * image edges are padded out to the next iMCU boundary with junk data; but
+ * no padding is possible at the top and left edges.  If we were to flip
+ * the whole image including the pad data, then pad garbage would become
+ * visible at the top and/or left, and real pixels would disappear into the
+ * pad margins --- perhaps permanently, since encoders & decoders may not
+ * bother to preserve DCT blocks that appear to be completely outside the
+ * nominal image area.  So, we have to exclude any partial iMCUs from the
+ * basic transformation.
+ *
+ * Transpose is the only transformation that can handle partial iMCUs at the
+ * right and bottom edges completely cleanly.  flip_h can flip partial iMCUs
+ * at the bottom, but leaves any partial iMCUs at the right edge untouched.
+ * Similarly flip_v leaves any partial iMCUs at the bottom edge untouched.
+ * The other transforms are defined as combinations of these basic transforms
+ * and process edge blocks in a way that preserves the equivalence.
+ *
+ * The "trim" option causes untransformable partial iMCUs to be dropped;
+ * this is not strictly lossless, but it usually gives the best-looking
+ * result for odd-size images.  Note that when this option is active,
+ * the expected mathematical equivalences between the transforms may not hold.
+ * (For example, -rot 270 -trim trims only the bottom edge, but -rot 90 -trim
+ * followed by -rot 180 -trim trims both edges.)
+ *
+ * We also offer a lossless-crop option, which discards data outside a given
+ * image region but losslessly preserves what is inside.  Like the rotate and
+ * flip transforms, lossless crop is restricted by the JPEG format: the upper
+ * left corner of the selected region must fall on an iMCU boundary.  If this
+ * does not hold for the given crop parameters, we silently move the upper left
+ * corner up and/or left to make it so, simultaneously increasing the region
+ * dimensions to keep the lower right crop corner unchanged.  (Thus, the
+ * output image covers at least the requested region, but may cover more.)
+ *
+ * We also provide a lossless-resize option, which is kind of a lossless-crop
+ * operation in the DCT coefficient block domain - it discards higher-order
+ * coefficients and losslessly preserves lower-order coefficients of a
+ * sub-block.
+ *
+ * Rotate/flip transform, resize, and crop can be requested together in a
+ * single invocation.  The crop is applied last --- that is, the crop region
+ * is specified in terms of the destination image after transform/resize.
+ *
+ * We also offer a "force to grayscale" option, which simply discards the
+ * chrominance channels of a YCbCr image.  This is lossless in the sense that
+ * the luminance channel is preserved exactly.  It's not the same kind of
+ * thing as the rotate/flip transformations, but it's convenient to handle it
+ * as part of this package, mainly because the transformation routines have to
+ * be aware of the option to know how many components to work on.
+ */
+
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jtransform_parse_crop_spec  jTrParCrop
+#define jtransform_request_workspace      jTrRequest
+#define jtransform_adjust_parameters      jTrAdjust
+#define jtransform_execute_transform      jTrExec
+#define jtransform_perfect_transform      jTrPerfect
+#define jcopy_markers_setup         jCMrkSetup
+#define jcopy_markers_execute       jCMrkExec
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+
+/*
+ * Codes for supported types of image transformations.
+ */
+
+typedef enum {
+      JXFORM_NONE,            /* no transformation */
+      JXFORM_FLIP_H,          /* horizontal flip */
+      JXFORM_FLIP_V,          /* vertical flip */
+      JXFORM_TRANSPOSE, /* transpose across UL-to-LR axis */
+      JXFORM_TRANSVERSE,      /* transpose across UR-to-LL axis */
+      JXFORM_ROT_90,          /* 90-degree clockwise rotation */
+      JXFORM_ROT_180,         /* 180-degree rotation */
+      JXFORM_ROT_270          /* 270-degree clockwise (or 90 ccw) */
+} JXFORM_CODE;
+
+/*
+ * Codes for crop parameters, which can individually be unspecified,
+ * positive, or negative.  (Negative width or height makes no sense, though.)
+ */
+
+typedef enum {
+      JCROP_UNSET,
+      JCROP_POS,
+      JCROP_NEG
+} JCROP_CODE;
+
+/*
+ * Transform parameters struct.
+ * NB: application must not change any elements of this struct after
+ * calling jtransform_request_workspace.
+ */
+
+typedef struct {
+  /* Options: set by caller */
+  JXFORM_CODE transform;      /* image transform operator */
+  boolean perfect;            /* if TRUE, fail if partial MCUs are requested */
+  boolean trim;               /* if TRUE, trim partial MCUs as needed */
+  boolean force_grayscale;    /* if TRUE, convert color image to grayscale */
+  boolean crop;               /* if TRUE, crop source image */
+
+  /* Crop parameters: application need not set these unless crop is TRUE.
+   * These can be filled in by jtransform_parse_crop_spec().
+   */
+  JDIMENSION crop_width;      /* Width of selected region */
+  JCROP_CODE crop_width_set;
+  JDIMENSION crop_height;     /* Height of selected region */
+  JCROP_CODE crop_height_set;
+  JDIMENSION crop_xoffset;    /* X offset of selected region */
+  JCROP_CODE crop_xoffset_set;      /* (negative measures from right edge) */
+  JDIMENSION crop_yoffset;    /* Y offset of selected region */
+  JCROP_CODE crop_yoffset_set;      /* (negative measures from bottom edge) */
+
+  /* Internal workspace: caller should not touch these */
+  int num_components;         /* # of components in workspace */
+  jvirt_barray_ptr * workspace_coef_arrays; /* workspace for transformations */
+  JDIMENSION output_width;    /* cropped destination dimensions */
+  JDIMENSION output_height;
+  JDIMENSION x_crop_offset;   /* destination crop offsets measured in iMCUs */
+  JDIMENSION y_crop_offset;
+  int iMCU_sample_width;      /* destination iMCU size */
+  int iMCU_sample_height;
+} jpeg_transform_info;
+
+
+#if TRANSFORMS_SUPPORTED
+
+/* Parse a crop specification (written in X11 geometry style) */
+EXTERN(boolean) jtransform_parse_crop_spec
+      JPP((jpeg_transform_info *info, const char *spec));
+/* Request any required workspace */
+EXTERN(boolean) jtransform_request_workspace
+      JPP((j_decompress_ptr srcinfo, jpeg_transform_info *info));
+/* Adjust output image parameters */
+EXTERN(jvirt_barray_ptr *) jtransform_adjust_parameters
+      JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+           jvirt_barray_ptr *src_coef_arrays,
+           jpeg_transform_info *info));
+/* Execute the actual transformation, if any */
+EXTERN(void) jtransform_execute_transform
+      JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+           jvirt_barray_ptr *src_coef_arrays,
+           jpeg_transform_info *info));
+/* Determine whether lossless transformation is perfectly
+ * possible for a specified image and transformation.
+ */
+EXTERN(boolean) jtransform_perfect_transform
+      JPP((JDIMENSION image_width, JDIMENSION image_height,
+           int MCU_width, int MCU_height,
+           JXFORM_CODE transform));
+
+/* jtransform_execute_transform used to be called
+ * jtransform_execute_transformation, but some compilers complain about
+ * routine names that long.  This macro is here to avoid breaking any
+ * old source code that uses the original name...
+ */
+#define jtransform_execute_transformation jtransform_execute_transform
+
+#endif /* TRANSFORMS_SUPPORTED */
+
+
+/*
+ * Support for copying optional markers from source to destination file.
+ */
+
+typedef enum {
+      JCOPYOPT_NONE,          /* copy no optional markers */
+      JCOPYOPT_COMMENTS,      /* copy only comment (COM) markers */
+      JCOPYOPT_ALL            /* copy all optional markers */
+} JCOPY_OPTION;
+
+#define JCOPYOPT_DEFAULT  JCOPYOPT_COMMENTS     /* recommended default */
+
+/* Setup decompression object to save desired markers in memory */
+EXTERN(void) jcopy_markers_setup
+      JPP((j_decompress_ptr srcinfo, JCOPY_OPTION option));
+/* Copy markers saved in the given source object to the destination object */
+EXTERN(void) jcopy_markers_execute
+      JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+           JCOPY_OPTION option));
+
+
+} // namespace DigiKam
+
+#endif // TRANSUPP_H
+
+#else // JPEG_LIB_VERSION >= 80
+
 /*
  * transupp.h
  *
@@ -143,3 +369,5 @@ EXTERN(void) jcopy_markers_execute
 } // namespace DigiKam
 
 #endif // TRANSUPP_H
+
+#endif // JPEG_LIB_VERSION >= 80