00001 //============================================== 00002 // copyright : (C) 2003-2005 by Will Stokes 00003 //============================================== 00004 // This program is free software; you can redistribute it 00005 // and/or modify it under the terms of the GNU General 00006 // Public License as published by the Free Software 00007 // Foundation; either version 2 of the License, or 00008 // (at your option) any later version. 00009 //============================================== 00010 00011 //Systemwide includes 00012 #include <qimage.h> 00013 #include <qstring.h> 00014 #include <qapplication.h> 00015 00016 //Projectwide includes 00017 #include "sepia.h" 00018 #include "../../gui/statusWidget.h" 00019 00020 //---------------------------------------------- 00021 // Inputs: 00022 // ------- 00023 // QString filename - location of original image on disk 00024 // StatusWidget* status - widget for making progress visible to user 00025 // 00026 // Outputs: 00027 // -------- 00028 // QImage* returned - constructed image 00029 // 00030 // Description: 00031 // ------------ 00032 // This method constructs a sepia version of 00033 // the image by computing a sepia value for each pixel. 00034 // The sepia effect is intended to mimick sepia coloring 00035 // obtained during traditional film development. 00036 // 00037 // First, a sepia color is chosen with a nice yellowy-orange tone 00038 // (r,g,b = 162,128,101). This color is next converted to HSL 00039 // (hue, saturation, luminance) space and used during sepia coloring. 00040 // 00041 // For each pixel, we construct a modified sepia color where the original 00042 // luminance (brightness) is replaced with that pixels luminance using 00043 // a weighted sum of the color channels. (For more information on image 00044 // luminance see the blackWhite effect). This modified sepia color is 00045 // converted back to RGB color space and used for the pixel color 00046 // in the modified image. This way image brightness is maintained 00047 // while color information is replaced with the sepia color. The 00048 // sepia color can be adjusted to produce a differnt overall color 00049 // feeling by changing the original sepia color. 00050 //---------------------------------------------- 00051 00052 //============================================== 00053 QImage* sepiaEffect( QString filename, StatusWidget* status ) 00054 { 00055 //load image 00056 QImage* editedImage = new QImage( filename ); 00057 00058 //determine if busy indicators will be used 00059 bool useBusyIndicators = (status != NULL); 00060 00061 //setup progress bar 00062 if(useBusyIndicators) 00063 { 00064 QString statusMessage = qApp->translate( "sepiaEffect", "Applying Sepia Effect:" ); 00065 status->showProgressBar( statusMessage, 100 ); 00066 qApp->processEvents(); 00067 } 00068 00069 //update progress bar for every 1% of completion 00070 const int updateIncrement = (int) ( 0.01 * editedImage->width() * editedImage->height() ); 00071 int newProgress = 0; 00072 00073 //compute the hsl/hsv coordinates of sepia color 00074 int sepiaH, sepiaS, sepiaL; 00075 QColor(162,128,101).getHsv( &sepiaH, &sepiaS, &sepiaL ); 00076 00077 //iterate over each selected scanline 00078 int x, y, pixelLuminance; 00079 QRgb* rgb; 00080 QColor sepiaColor; 00081 uchar* scanLine; 00082 00083 for( y=0; y<editedImage->height(); y++) 00084 { 00085 //iterate over each selected pixel in scanline 00086 scanLine = editedImage->scanLine(y); 00087 for( x=0; x<editedImage->width(); x++) 00088 { 00089 //compute gray value based on the display luminance of color coordinates 00090 rgb = ((QRgb*)scanLine+x); 00091 pixelLuminance = (int)(0.3*qRed(*rgb) + 0.59*qGreen(*rgb) + 0.11*qBlue(*rgb)); 00092 00093 //compute and set sepia color 00094 sepiaColor.setHsv( sepiaH, sepiaS, pixelLuminance ); 00095 *rgb = sepiaColor.rgb(); 00096 00097 //update status bar if significant progress has been made since last update 00098 if(useBusyIndicators) 00099 { 00100 newProgress++; 00101 if(newProgress >= updateIncrement) 00102 { 00103 newProgress = 0; 00104 status->incrementProgress(); 00105 qApp->processEvents(); 00106 } 00107 } 00108 00109 } 00110 } 00111 00112 //return pointer to edited image 00113 return editedImage; 00114 } 00115 //==============================================