AlbumShaper  1.0a3
sepia.cpp
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1 //==============================================
2 // copyright : (C) 2003-2005 by Will Stokes
3 //==============================================
4 // This program is free software; you can redistribute it
5 // and/or modify it under the terms of the GNU General
6 // Public License as published by the Free Software
7 // Foundation; either version 2 of the License, or
8 // (at your option) any later version.
9 //==============================================
10 
11 //Systemwide includes
12 #include <qimage.h>
13 #include <qstring.h>
14 #include <qapplication.h>
15 
16 //Projectwide includes
17 #include "sepia.h"
18 #include "manipulationOptions.h"
19 #include "../../gui/statusWidget.h"
20 
21 //----------------------------------------------
22 // Inputs:
23 // -------
24 // QString filename - location of original image on disk
25 // StatusWidget* status - widget for making progress visible to user
26 //
27 // Outputs:
28 // --------
29 // QImage* returned - constructed image
30 //
31 // Description:
32 // ------------
33 // This method constructs a sepia version of
34 // the image by computing a sepia value for each pixel.
35 // The sepia effect is intended to mimick sepia coloring
36 // obtained during traditional film development.
37 //
38 // First, a sepia color is chosen with a nice yellowy-orange tone
39 // (r,g,b = 162,128,101). This color is next converted to HSL
40 // (hue, saturation, luminance) space and used during sepia coloring.
41 //
42 // For each pixel, we construct a modified sepia color where the original
43 // luminance (brightness) is replaced with that pixels luminance using
44 // a weighted sum of the color channels. (For more information on image
45 // luminance see the blackWhite effect). This modified sepia color is
46 // converted back to RGB color space and used for the pixel color
47 // in the modified image. This way image brightness is maintained
48 // while color information is replaced with the sepia color. The
49 // sepia color can be adjusted to produce a differnt overall color
50 // feeling by changing the original sepia color.
51 //----------------------------------------------
52 
53 //==============================================
54 QImage* sepiaEffect( QString filename, ManipulationOptions* options )
55 {
56  //load image
57  QImage* editedImage = new QImage( filename );
58 
59  //convert to 32-bit depth if necessary
60  if( editedImage->depth() < 32 )
61  {
62  QImage* tmp = editedImage;
63  editedImage = new QImage( tmp->convertDepth( 32, Qt::AutoColor ) );
64  delete tmp; tmp=NULL;
65  }
66 
67  //determine if busy indicators will be used
68  bool useBusyIndicators = false;
69  StatusWidget* status = NULL;
70  if( options != NULL && options->getStatus() != NULL )
71  {
72  useBusyIndicators = true;
73  status = options->getStatus();
74  }
75 
76  //setup progress bar
77  if(useBusyIndicators)
78  {
79  QString statusMessage = qApp->translate( "sepiaEffect", "Applying Sepia Effect:" );
80  status->showProgressBar( statusMessage, 100 );
81  qApp->processEvents();
82  }
83 
84  //update progress bar for every 1% of completion
85  const int updateIncrement = (int) ( 0.01 * editedImage->width() * editedImage->height() );
86  int newProgress = 0;
87 
88  //compute the hsl/hsv coordinates of sepia color
89  int sepiaH, sepiaS, sepiaL;
90  QColor(162,128,101).getHsv( &sepiaH, &sepiaS, &sepiaL );
91 
92  //iterate over each selected scanline
93  int x, y, pixelLuminance;
94  QRgb* rgb;
95  QColor sepiaColor;
96  uchar* scanLine;
97 
98  for( y=0; y<editedImage->height(); y++)
99  {
100  //iterate over each selected pixel in scanline
101  scanLine = editedImage->scanLine(y);
102  for( x=0; x<editedImage->width(); x++)
103  {
104  //compute gray value based on the display luminance of color coordinates
105  rgb = ((QRgb*)scanLine+x);
106  pixelLuminance = (int) (0.2125*qRed(*rgb) + 0.7154*qGreen(*rgb) + 0.0721*qBlue(*rgb));
107 
108  //compute and set sepia color
109  sepiaColor.setHsv( sepiaH, sepiaS, pixelLuminance );
110  *rgb = sepiaColor.rgb();
111 
112  //update status bar if significant progress has been made since last update
113  if(useBusyIndicators)
114  {
115  newProgress++;
116  if(newProgress >= updateIncrement)
117  {
118  newProgress = 0;
119  status->incrementProgress();
120  qApp->processEvents();
121  }
122  }
123 
124  }
125  }
126 
127  //return pointer to edited image
128  return editedImage;
129 }
130 //==============================================
int updateIncrement
StatusWidget * getStatus()
void incrementProgress()
Updates the progress bar by one step.
void showProgressBar(QString message, int numSteps)
Initializes the progress bar.
QImage * sepiaEffect(QString filename, ManipulationOptions *options)
Definition: sepia.cpp:54
StatusWidget * status
QImage * editedImage
int newProgress