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Diffstat (limited to 'src/imageutils/imageutils.cpp')
| -rw-r--r-- | src/imageutils/imageutils.cpp | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/src/imageutils/imageutils.cpp b/src/imageutils/imageutils.cpp new file mode 100644 index 0000000..c9d04ca --- /dev/null +++ b/src/imageutils/imageutils.cpp @@ -0,0 +1,211 @@ +// vim: set tabstop=4 shiftwidth=4 noexpandtab +/* +Gwenview - A simple image viewer for KDE +Copyright 2000-2004 Aurélien Gâteau + +This program is free software; you can redistribute it and/or +modify it under the terms of the GNU General Public License +as published by the Free Software Foundation; either version 2 +of the License, or (at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +*/ +#include <math.h> + +// Qt +#include <qimage.h> +#include <qwmatrix.h> + +// KDE +#include <kdebug.h> +#include <kdeversion.h> +#include <kglobal.h> + +// Local +#include "imageutils/orientation.h" + +namespace ImageUtils { + + +QWMatrix transformMatrix(Orientation orientation) { + QWMatrix matrix; + switch (orientation) { + case NOT_AVAILABLE: + case NORMAL: + break; + + case HFLIP: + matrix.scale(-1,1); + break; + + case ROT_180: + matrix.rotate(180); + break; + + case VFLIP: + matrix.scale(1,-1); + break; + + case TRANSPOSE: + matrix.scale(-1,1); + matrix.rotate(90); + break; + + case ROT_90: + matrix.rotate(90); + break; + + case TRANSVERSE: + matrix.scale(1,-1); + matrix.rotate(90); + break; + + case ROT_270: + matrix.rotate(270); + break; + } + + return matrix; +} + + +QImage transform(const QImage& img, Orientation orientation) { + if (orientation != NOT_AVAILABLE && orientation != NORMAL) { + return img.xForm(transformMatrix(orientation)); + } else { + return img; + } +} + + +inline +int changeBrightness( int value, int brightness ) + { + return KCLAMP( value + brightness * 255 / 100, 0, 255 ); + } + +inline +int changeContrast( int value, int contrast ) + { + return KCLAMP((( value - 127 ) * contrast / 100 ) + 127, 0, 255 ); + } + +inline +int changeGamma( int value, int gamma ) + { + return KCLAMP( int( pow( value / 255.0, 100.0 / gamma ) * 255 ), 0, 255 ); + } + +inline +int changeUsingTable( int value, const int table[] ) + { + return table[ value ]; + } + +/* + Applies either brightness, contrast or gamma conversion on the image. + If the image is not truecolor, the color table is changed. If it is + truecolor, every pixel has to be changed. In order to make it as fast + as possible, alpha value is converted only if necessary. Additionally, + since color components (red/green/blue/alpha) can have only 256 values + but images usually have many pixels, a conversion table is first + created for every color component value, and pixels are converted + using this table. +*/ + +template< int operation( int, int ) > +static +QImage changeImage( const QImage& image, int value ) + { + QImage im = image; + im.detach(); + if( im.numColors() == 0 ) /* truecolor */ + { + if( im.depth() != 32 ) /* just in case */ + im = im.convertDepth( 32 ); + int table[ 256 ]; + for( int i = 0; + i < 256; + ++i ) + table[ i ] = operation( i, value ); + if( im.hasAlphaBuffer()) + { + for( int y = 0; + y < im.height(); + ++y ) + { + QRgb* line = reinterpret_cast< QRgb* >( im.scanLine( y )); + for( int x = 0; + x < im.width(); + ++x ) + line[ x ] = qRgba( changeUsingTable( qRed( line[ x ] ), table ), + changeUsingTable( qGreen( line[ x ] ), table ), + changeUsingTable( qBlue( line[ x ] ), table ), + changeUsingTable( qAlpha( line[ x ] ), table )); + } + } + else + { + for( int y = 0; + y < im.height(); + ++y ) + { + QRgb* line = reinterpret_cast< QRgb* >( im.scanLine( y )); + for( int x = 0; + x < im.width(); + ++x ) + line[ x ] = qRgb( changeUsingTable( qRed( line[ x ] ), table ), + changeUsingTable( qGreen( line[ x ] ), table ), + changeUsingTable( qBlue( line[ x ] ), table )); + } + } + } + else + { + QRgb* colors = im.colorTable(); + for( int i = 0; + i < im.numColors(); + ++i ) + colors[ i ] = qRgb( operation( qRed( colors[ i ] ), value ), + operation( qGreen( colors[ i ] ), value ), + operation( qBlue( colors[ i ] ), value )); + } + return im; + } + + +// brightness is multiplied by 100 in order to avoid floating point numbers +QImage changeBrightness( const QImage& image, int brightness ) + { + if( brightness == 0 ) // no change + return image; + return changeImage< changeBrightness >( image, brightness ); + } + + +// contrast is multiplied by 100 in order to avoid floating point numbers +QImage changeContrast( const QImage& image, int contrast ) + { + if( contrast == 100 ) // no change + return image; + return changeImage< changeContrast >( image, contrast ); + } + +// gamma is multiplied by 100 in order to avoid floating point numbers +QImage changeGamma( const QImage& image, int gamma ) + { + if( gamma == 100 ) // no change + return image; + return changeImage< changeGamma >( image, gamma ); + } + +} // Namespace + |