Add false color rendering

imagescrollareagl.cpp

@@ -274,6 +274,12 @@ void ImageWidget::invert(bool enable)
     update();
 }
 
+void ImageWidget::falseColor(bool enable)
+{
+    m_falseColor = enable;
+    update();
+}
+
 QImage ImageWidget::renderToImage()
 {
     if(m_imgWidth < 0)return QImage();
@@ -402,6 +408,7 @@ void ImageWidget::paintGL()
         m_program->setUniformValue("mtf_param", m_low, m_mid, m_high);
         m_program->setUniformValue("zoom", 1.0f/m_scale);
         m_program->setUniformValue("bw", m_bwImg && !m_superpixel);
+        m_program->setUniformValue("false_color", m_falseColor && m_bwImg);
         m_program->setUniformValue("invert", m_invert);
         if(m_superpixel)m_program->setUniformValue("whiteBalance", m_whiteBalance[0], m_whiteBalance[1], m_whiteBalance[2]);
         else m_program->setUniformValue("whiteBalance", 1.0f, 1.0f, 1.0f);

imagescrollareagl.h

@@ -57,6 +57,7 @@ class ImageWidget : public QOpenGLWidget
     float m_whiteBalance[3] = {1.0f, 1.0f, 1.0f};
     bool m_blockRepaint;
     bool m_bwImg;
+    bool m_falseColor = false;
     bool m_invert;
     bool m_superpixel;
     bool m_showThumbnails;
@@ -85,6 +86,7 @@ public slots:
     void setOffset(float dx, float dy);
     void superPixel(bool enable);
     void invert(bool enable);
+    void falseColor(bool enable);
     QImage renderToImage();
     void thumbnailLoaded(const Image *image);
     void showThumbnail(bool enable);

mainwindow.cpp

@@ -84,6 +84,7 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
     connect(m_stretchPanel, &StretchToolbar::autoStretch, [&](){ m_stretchPanel->stretchImage(m_ringList->currentImage().get()); });
     connect(m_stretchPanel, &StretchToolbar::invert, m_imageGL->imageWidget(), &ImageWidget::invert);
     connect(m_stretchPanel, &StretchToolbar::superPixel, m_imageGL->imageWidget(), &ImageWidget::superPixel);
+    connect(m_stretchPanel, &StretchToolbar::falseColor, m_imageGL->imageWidget(), &ImageWidget::falseColor);
 
     m_ringList = new ImageRingList(m_database, nameFilter, this);
     m_filesystem = new FilesystemWidget(m_ringList, this);

resources.qrc

@@ -17,14 +17,15 @@
         <file>shaders/thumb.vert</file>
         <file>shaders/debayer.frag</file>
         <file>shaders/debayer.vert</file>
+        <file>falsecolor.png</file>
     </qresource>
-    <qresource lang="en" prefix="/">
+    <qresource prefix="/" lang="en">
         <file alias="help">about/help_en</file>
     </qresource>
-    <qresource lang="sk" prefix="/">
+    <qresource prefix="/" lang="sk">
         <file alias="help">about/help_sk</file>
     </qresource>
-    <qresource lang="fr" prefix="/">
+    <qresource prefix="/" lang="fr">
         <file alias="help">about/help_fr</file>
     </qresource>
 </RCC>

shaders/image.frag

@@ -5,6 +5,7 @@ uniform vec3 mtf_param;
 uniform bool bw;
 uniform bool invert;
 uniform bool srgb;
+uniform bool false_color;
 uniform vec3 whiteBalance;
 in vec2 qt_TexCoord0;
 layout(location = 0) out vec4 color;
@@ -23,6 +24,20 @@ vec4 MTF(vec4 x, vec3 m)
     return ((m.y - 1) * x) / ((2 * m.y - 1) * x - m.y);
 }
 
+vec3 falsecolor(float color)
+{
+    const vec3 pallete[] = vec3[](
+            vec3(1.0, 0.0, 1.0), //magneta
+            vec3(0.0, 0.0, 1.0), //blue
+            vec3(0.0, 1.0, 1.0), //cyan
+            vec3(0.0, 1.0, 0.0), //green
+            vec3(1.0, 1.0, 0.0), //yellow
+            vec3(1.0, 0.0, 0.0), vec3(1.0, 0.0, 0.0));//red
+    color *= 5.0;
+    int i = int(color);
+    return mix(pallete[i], pallete[i+1], fract(color));
+}
+
 vec3 checker()
 {
     vec2 pattern = fract(gl_FragCoord.xy * 0.0625) - 0.5;
@@ -34,6 +49,7 @@ void main(void)
     color = texture(qt_Texture0, qt_TexCoord0);
     if(bw)color = color.rrra;
     color = MTF(color, mtf_param);
+    if(false_color)color.rgb = falsecolor(color.r);
 
     if(invert)color.rgb = vec3(1.0) - color.rgb;
 

stretchtoolbar.cpp

@@ -34,6 +34,10 @@ StretchToolbar::StretchToolbar(QWidget *parent) : QToolBar(tr("Stretch toolbar")
     invertButton->setCheckable(true);
     connect(invertButton, SIGNAL(toggled(bool)), this, SIGNAL(invert(bool)));
 
+    QAction *falseColorButton = addAction(QIcon(":/falsecolor.png"), tr("False color"));
+    falseColorButton->setCheckable(true);
+    connect(falseColorButton, SIGNAL(toggled(bool)), this, SIGNAL(falseColor(bool)));
+
     QAction *superPixelButton = addAction(QIcon(":/bayer.png"), tr("Debayer CFA"));
     superPixelButton->setCheckable(true);
     connect(superPixelButton, SIGNAL(toggled(bool)), this, SIGNAL(superPixel(bool)));

stretchtoolbar.h

@@ -22,6 +22,7 @@ signals:
     void autoStretch();
     void invert(bool enable);
     void superPixel(bool enable);
+    void falseColor(bool enable);
 };
 
 #endif // STRETCHTOOLBAR_H