jfjoch_viewer: Improve HDR mode

viewer/JFJochViewerWindow.cpp

@@ -159,6 +159,9 @@ JFJochViewerWindow::JFJochViewerWindow(QWidget *parent, bool dbus, const QString
     connect(toolBarDisplay, &JFJochViewerToolbarDisplay::setAutoForeground, viewer,
             &JFJochDiffractionImage::setAutoForeground);
 
+    connect(toolBarDisplay, &JFJochViewerToolbarDisplay::setHDRMode, viewer,
+            &JFJochImage::setHDRMode);
+
     connect(toolBarDisplay, &JFJochViewerToolbarDisplay::colorMapChanged, viewer,
             &JFJochDiffractionImage::setColorMap);
 

viewer/image_viewer/JFJochImage.cpp

@@ -600,7 +600,9 @@ void JFJochImage::GeneratePixmap() {
     const auto &lut_data = color_scale.LUTData();
     const int64_t lutSize = lut_data.size();
     const float lutScale = static_cast<float>(lutSize - 1);
-    const float invRange = (maxv > minv) ? (1.0f / (maxv - minv)) * lutScale : 0.0f;
+    const float range = maxv - minv;
+    const float invRange = (range > 0) ? (lutScale / range) : 0.0f;
+    const float invRangeLog = (range > 0) ? (lutScale / std::log1p(range)) : 0.0f;
 
     rgb gap_color = color_scale.Apply(ColorScaleSpecial::Gap);
     for (int y = 0; y < H; ++y) {
@@ -619,7 +621,22 @@ void JFJochImage::GeneratePixmap() {
                     c = std::signbit(fp) ? bad_color : sat_color;
                 }
             } else {
-                auto idx = static_cast<int>((fp - minv) * invRange + 0.5f);
+                float f;
+                const float fp_minv = fp - minv;
+
+                if (hdr_mode) {
+                    if (fp_minv <= 0.0f)
+                        f = 0.0f;
+                    else if (fp_minv >= range)
+                        f = lutSize;
+                    else
+                        f = std::log1p(fp_minv) * invRangeLog;
+                } else
+                    f = fp_minv * invRange;
+
+                if (f < 0.0f) f = 0.0f;
+
+                auto idx = static_cast<int>(f + 0.5f);
                 if (idx <= 0) idx = 0;
                 else if (idx >= lutSize) idx = lutSize - 1;
                 c = lut_data[idx];
@@ -849,3 +866,9 @@ void JFJochImage::adjustForeground(bool input) {
 }
 
 void JFJochImage::beforeOverlayCleared() {}
+
+void JFJochImage::setHDRMode(bool input) {
+    hdr_mode = input;
+    GeneratePixmap();
+    Redraw();
+}

viewer/image_viewer/JFJochImage.h

@@ -36,6 +36,7 @@ protected:
 
     bool auto_bg = false;
     bool auto_fg = false;
+    bool hdr_mode = false;
 
     double scale_factor = 1.0;
 
@@ -108,6 +109,7 @@ public slots:
     void fitToView();
 
     void adjustForeground(bool input);
+    void setHDRMode(bool input);
 public:
     explicit JFJochImage(QWidget *parent = nullptr);
 };

viewer/toolbar/JFJochViewerToolbarDisplay.cpp

@@ -21,6 +21,11 @@ JFJochViewerToolbarDisplay::JFJochViewerToolbarDisplay(QWidget *parent)
     auto_foreground_button->setChecked(false);
     addWidget(auto_foreground_button);
 
+    hdr_mode_button = new QPushButton("HDR");
+    hdr_mode_button->setCheckable(true);
+    hdr_mode_button->setChecked(false);
+    addWidget(hdr_mode_button);
+
     addWidget(new QLabel("&nbsp;&nbsp;<b>Color map</b>&nbsp;&nbsp;"));
 
     // Initialize QComboBox with the options
@@ -41,7 +46,7 @@ JFJochViewerToolbarDisplay::JFJochViewerToolbarDisplay(QWidget *parent)
     connect(color_map_select, QOverload<int>::of(&QComboBox::currentIndexChanged),
             this, &JFJochViewerToolbarDisplay::colorComboBoxSet);
     connect(auto_foreground_button, &QPushButton::clicked, this, &JFJochViewerToolbarDisplay::autoForegroundButtonPressed);
-
+    connect(hdr_mode_button, &QPushButton::clicked, this, &JFJochViewerToolbarDisplay::HDRModeButtonPressed);
     auto *stretch = new QWidget(this);
     stretch->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
     addWidget(stretch);
@@ -60,7 +65,6 @@ void JFJochViewerToolbarDisplay::colorComboBoxSet(int val) {
     emit colorMapChanged(val);
 }
 
-
 void JFJochViewerToolbarDisplay::autoForegroundButtonPressed() {
     emit setAutoForeground(auto_foreground_button->isChecked());
 }
@@ -70,15 +74,18 @@ void JFJochViewerToolbarDisplay::updateAutoForeground(bool val) {
     auto_foreground_button->setChecked(val);
 }
 
+void JFJochViewerToolbarDisplay::HDRModeButtonPressed() {
+    emit setHDRMode(hdr_mode_button->isChecked());
+}
+
 void JFJochViewerToolbarDisplay::imageLoaded(std::shared_ptr<const JFJochReaderImage> image) {
     if (image) {
         auto valid = image->ValidMinMax();
-        if (valid.has_value())
+        if (valid.has_value() && valid->second > 1)
             foreground_slider->setMax(valid->second);
         else
             foreground_slider->setMax(MAX_SLIDER_NO_IMAGE);
     } else {
         foreground_slider->setMax(MAX_SLIDER_NO_IMAGE);
     }
-
 }

viewer/toolbar/JFJochViewerToolbarDisplay.h

@@ -17,7 +17,7 @@ class JFJochViewerToolbarDisplay : public QToolBar {
 
     SliderPlusBox *foreground_slider;
     QPushButton *auto_foreground_button;
-
+    QPushButton *hdr_mode_button;
     QComboBox *color_map_select;
 public:
     JFJochViewerToolbarDisplay(QWidget *parent = nullptr);
@@ -26,6 +26,7 @@ signals:
     void setForeground(float val);
     void colorMapChanged(int val);
     void setAutoForeground(bool val);
+    void setHDRMode(bool val);
 
 public slots:
     void updateForeground(float val);
@@ -35,6 +36,7 @@ private slots:
     void foregroundSet(double val);
     void colorComboBoxSet(int val);
     void autoForegroundButtonPressed();
+    void HDRModeButtonPressed();
 };