Small refactoring, extract CIE factors

See kde/kdenlive#655

dev-docs/architecture.md

@@ -6,7 +6,6 @@
   * Dependencies MLT etc.
   * MVC
   * GUI elements and their counterpart
-* [kdenlivesettings.kcfg](../src/kdenlivesettings.kcfg)
 
 
 ## Architectural Overview

dev-docs/build.md

@@ -42,7 +42,7 @@ sudo apt install libkf5archive-dev libkf5bookmarks-dev libkf5coreaddons-dev \
                  libkf5purpose-dev libkf5iconthemes-dev kdoctools-dev libkf5crash-dev \
                  libkf5filemetadata-dev  kio kinit qtdeclarative5-dev libqt5svg5-dev \
                  qml-module-qtquick-controls qtmultimedia5-dev qtquickcontrols2-5-dev \
-                 appstream gettext libv4l-dev breeze
+                 appstream gettext libv4l-dev libqt5webkit5-dev librttr-dev breeze ffmpeg
 ```
 
 Most development packages will already be installed with the following command:

dev-docs/coding.md

+# Coding and Resources
+
+* [All Qt5 classes][qt5c]
+* [MLT introduction][mlt-intro].
+
+## Configuration
+
+Named settings are stored in [`kdenlivesettings.kcfg`][sett]. To add a new
+setting with default value, add an entry in the settings file, for example:
+
+```xml
+<entry name="logscale" type="Bool">
+  <label>Use logarithmic scale</label>
+  <default>true</default>
+</entry>
+```
+
+The setting can then be read and written as follows:
+
+```cpp
+// Read
+bool logScale = KdenliveSettings::logscale();
+
+// Write
+KdenliveSettings::setLogscale(true);
+```
+
+[sett]: ../src/kdenlivesettings.kcfg
+[mlt-intro]: https://www.mltframework.org/docs/framework/
+[qt5c]: https://doc.qt.io/qt-5/classes.html

src/scopes/colorscopes/CMakeLists.txt

 set(kdenlive_SRCS
   ${kdenlive_SRCS}
+  scopes/colorscopes/colorconstants.h
   scopes/colorscopes/abstractgfxscopewidget.cpp
   scopes/colorscopes/colorplaneexport.cpp
   scopes/colorscopes/histogram.cpp

src/scopes/colorscopes/colorconstants.h

+#ifndef KDENLIVE_COLORCONSTANTS_H
+#define KDENLIVE_COLORCONSTANTS_H
+
+/**
+ * ITU-R Recommendation for luminance calculation.
+ * See http://www.poynton.com/ColorFAQ.html for details.
+ */
+enum class ITURec {
+    Rec_601, Rec_709
+};
+
+// CIE 601 luminance factors
+constexpr float REC_601_R = .299;
+constexpr float REC_601_G = .587;
+constexpr float REC_601_B = .114;
+
+// CIE 709 luminance factors
+constexpr float REC_709_R = .2125;
+constexpr float REC_709_G = .7154;
+constexpr float REC_709_B = .0721;
+
+#endif //KDENLIVE_COLORCONSTANTS_H

src/scopes/colorscopes/histogram.cpp

@@ -15,6 +15,7 @@
 #include "klocalizedstring.h"
 #include <KConfigGroup>
 #include <KSharedConfig>
+#include <QtWidgets/QButtonGroup>
 
 Histogram::Histogram(QWidget *parent)
     : AbstractGfxScopeWidget(false, parent)
@@ -39,6 +40,10 @@ Histogram::Histogram(QWidget *parent)
     m_menu->addAction(m_aRec601);
     m_menu->addAction(m_aRec709);
 
+    QButtonGroup scaleGroup;
+    scaleGroup.addButton(m_ui->rbLinear);
+    scaleGroup.addButton(m_ui->rbLogarithmic);
+
     connect(m_ui->cbY, &QAbstractButton::toggled, this, &AbstractScopeWidget::forceUpdateScope);
     connect(m_ui->cbS, &QAbstractButton::toggled, this, &AbstractScopeWidget::forceUpdateScope);
     connect(m_ui->cbR, &QAbstractButton::toggled, this, &AbstractScopeWidget::forceUpdateScope);
@@ -47,6 +52,7 @@ Histogram::Histogram(QWidget *parent)
     connect(m_aUnscaled, &QAction::toggled, this, &Histogram::forceUpdateScope);
     connect(m_aRec601, &QAction::toggled, this, &Histogram::forceUpdateScope);
     connect(m_aRec709, &QAction::toggled, this, &Histogram::forceUpdateScope);
+    connect(m_ui->rbLogarithmic, &QAbstractButton::toggled, this, &Histogram::forceUpdateScope);
 
     init();
     m_histogramGenerator = new HistogramGenerator();
@@ -76,6 +82,7 @@ void Histogram::readConfig()
     m_ui->cbB->setChecked(scopeConfig.readEntry("bEnabled", true));
     m_aRec601->setChecked(scopeConfig.readEntry("rec601", false));
     m_aRec709->setChecked(!m_aRec601->isChecked());
+    m_ui->rbLogarithmic->setChecked(scopeConfig.readEntry("logScale", false));
 }
 
 void Histogram::writeConfig()
@@ -88,6 +95,7 @@ void Histogram::writeConfig()
     scopeConfig.writeEntry("gEnabled", m_ui->cbG->isChecked());
     scopeConfig.writeEntry("bEnabled", m_ui->cbB->isChecked());
     scopeConfig.writeEntry("rec601", m_aRec601->isChecked());
+    scopeConfig.writeEntry("logScale", m_ui->rbLogarithmic->isChecked());
     scopeConfig.sync();
 }
 
@@ -131,9 +139,9 @@ QImage Histogram::renderGfxScope(uint accelFactor, const QImage &qimage)
         (m_ui->cbR->isChecked() ? 1 : 0) * HistogramGenerator::ComponentR | (m_ui->cbG->isChecked() ? 1 : 0) * HistogramGenerator::ComponentG |
         (m_ui->cbB->isChecked() ? 1 : 0) * HistogramGenerator::ComponentB;
 
-    HistogramGenerator::Rec rec = m_aRec601->isChecked() ? HistogramGenerator::Rec_601 : HistogramGenerator::Rec_709;
+    ITURec rec = m_aRec601->isChecked() ? ITURec::Rec_601 : ITURec::Rec_709;
 
-    QImage histogram = m_histogramGenerator->calculateHistogram(m_scopeRect.size(), qimage, componentFlags, rec, m_aUnscaled->isChecked(), accelFactor);
+    QImage histogram = m_histogramGenerator->calculateHistogram(m_scopeRect.size(), qimage, componentFlags, rec, m_aUnscaled->isChecked(), m_ui->rbLogarithmic->isChecked(), accelFactor);
 
     emit signalScopeRenderingFinished(uint(timer.elapsed()), accelFactor);
     return histogram;

src/scopes/colorscopes/histogramgenerator.cpp

@@ -9,6 +9,7 @@
  ***************************************************************************/
 
 #include "histogramgenerator.h"
+#include "colorconstants.h"
 
 #include "klocalizedstring.h"
 #include <QImage>
@@ -18,7 +19,8 @@
 
 HistogramGenerator::HistogramGenerator() = default;
 
-QImage HistogramGenerator::calculateHistogram(const QSize &paradeSize, const QImage &image, const int &components, HistogramGenerator::Rec rec, bool unscaled,
+QImage HistogramGenerator::calculateHistogram(const QSize &paradeSize, const QImage &image, const int &components,
+                                              ITURec rec, bool unscaled, bool logScale,
                                               uint accelFactor) const
 {
     if (paradeSize.height() <= 0 || paradeSize.width() <= 0 || image.width() <= 0 || image.height() <= 0) {
@@ -39,27 +41,27 @@ QImage HistogramGenerator::calculateHistogram(const QSize &paradeSize, const QIm
     std::fill(y, y + 256, 0);
     std::fill(s, s + 766, 0);
 
-    const uint iw = (uint)image.bytesPerLine();
-    const uint ih = (uint)image.height();
     const uint ww = (uint)paradeSize.width();
     const uint wh = (uint)paradeSize.height();
-    const uint byteCount = iw * ih;
 
     // Read the stats from the input image
     for (int Y = 0; Y < image.height(); ++Y) {
         for (int X = 0; X < image.width(); X += (int)accelFactor) {
+
             QRgb col = image.pixel(X, Y);
             r[qRed(col)]++;
             g[qGreen(col)]++;
             b[qBlue(col)]++;
+
             if (drawY) {
                 // Use if branch to avoid expensive multiplication if Y disabled
-                if (rec == HistogramGenerator::Rec_601) {
-                    y[(int)floor(.299 * qRed(col) + .587 * qGreen(col) + .114 * qBlue(col))]++;
+                if (rec == ITURec::Rec_601) {
+                    y[(int)floor(REC_601_R * (float) qRed(col) + REC_601_G * (float) qGreen(col) + REC_601_B * (float) qBlue(col))]++;
                 } else {
-                    y[(int)floor(.2125 * qRed(col) + .7154 * qGreen(col) + .0721 * qBlue(col))]++;
+                    y[(int)floor(REC_709_R * (float) qRed(col) + REC_709_G * (float) qGreen(col) + REC_709_B * (float) qBlue(col))]++;
                 }
             }
+
             if (drawSum) {
                 // Use an if branch here because the sum takes more operations than rgb
                 s[qRed(col)]++;
@@ -75,53 +77,68 @@ QImage HistogramGenerator::calculateHistogram(const QSize &paradeSize, const QIm
         return QImage();
     }
 
-    const int d = 20; // Distance for text
+    // Distance for text
+    const int d = 20;
+
+    // Height of a single histogram box without text
     const int partH = int((int)wh - nParts * d) / nParts;
+
+    // Total number of bytes of the image
+    const uint byteCount = (uint) image.sizeInBytes();
+
+    // Factor for scaling the measured value to the histogram.
+    // This factor is used for linear scaling and does not depend
+    // on the measured histogram values. Very large values,
+    // e.g. in an image with a lot of white, are clipped.
+    // Otherwise, the relatively low height of the histogram
+    // would show all other values close to 0 when one bin is very high.
     float scaling = 0;
     int div = (int)byteCount >> 7;
     if (div > 0) {
-        scaling = (float)partH / float((int)byteCount >> 7);
+        scaling = (float)partH / float(byteCount >> 7);
     }
     const int dist = 40;
 
-    int wy = 0; // Drawing position
-
     QImage histogram(paradeSize, QImage::Format_ARGB32);
     QPainter davinci(&histogram);
     davinci.setPen(QColor(220, 220, 220, 255));
     histogram.fill(qRgba(0, 0, 0, 0));
 
-    if (drawY) {
-        drawComponentFull(&davinci, y, scaling, QRect(0, wy, (int)ww, partH + dist), QColor(220, 220, 210, 255), dist, unscaled, 256);
+    QColor neutralColor(220, 220, 210, 255);
+    QColor redColor(255, 128, 0, 255);
+    QColor greenColor(128, 255, 0, 255);
+    QColor blueColor(0, 128, 255, 255);
 
+    int wy = 0; // Drawing position
+
+    if (drawY) {
+        drawComponentFull(&davinci, y, scaling, QRect(0, wy, (int)ww, partH + dist), neutralColor, dist, unscaled, logScale, 256);
         wy += partH + d;
     }
 
     if (drawSum) {
-        drawComponentFull(&davinci, s, scaling / 3, QRect(0, wy, (int)ww, partH + dist), QColor(220, 220, 210, 255), dist, unscaled, 256);
-
+        drawComponentFull(&davinci, s, scaling / 3, QRect(0, wy, (int)ww, partH + dist), neutralColor, dist, unscaled, logScale, 256);
         wy += partH + d;
     }
 
     if (drawR) {
-        drawComponentFull(&davinci, r, scaling, QRect(0, wy, (int)ww, partH + dist), QColor(255, 128, 0, 255), dist, unscaled, 256);
-
+        drawComponentFull(&davinci, r, scaling, QRect(0, wy, (int)ww, partH + dist), redColor, dist, unscaled, logScale, 256);
         wy += partH + d;
     }
 
     if (drawG) {
-        drawComponentFull(&davinci, g, scaling, QRect(0, wy, (int)ww, partH + dist), QColor(128, 255, 0, 255), dist, unscaled, 256);
+        drawComponentFull(&davinci, g, scaling, QRect(0, wy, (int)ww, partH + dist), greenColor, dist, unscaled, logScale, 256);
         wy += partH + d;
     }
 
     if (drawB) {
-        drawComponentFull(&davinci, b, scaling, QRect(0, wy, (int)ww, partH + dist), QColor(0, 128, 255, 255), dist, unscaled, 256);
+        drawComponentFull(&davinci, b, scaling, QRect(0, wy, (int)ww, partH + dist), blueColor, dist, unscaled, logScale, 256);
     }
 
     return histogram;
 }
 
-QImage HistogramGenerator::drawComponent(const int *y, const QSize &size, const float &scaling, const QColor &color, bool unscaled, uint max) const
+QImage HistogramGenerator::drawComponent(const int *y, const QSize &size, const float &scaling, const QColor &color, bool unscaled, bool logScale, uint max)
 {
     QImage component((int)max, size.height(), QImage::Format_ARGB32);
     component.fill(qRgba(0, 0, 0, 255));
@@ -129,9 +146,18 @@ QImage HistogramGenerator::drawComponent(const int *y, const QSize &size, const
 
     const int partH = size.height();
 
+    const int maxBinSize = *std::max_element(&y[0], &y[max - 1]);
+    const float logScaling = float(size.height()) / log10f(float(maxBinSize + 1));
+
     for (uint x = 0; x < max; ++x) {
+
         // Calculate the height of the curve at position x
-        int partY = int(scaling * (float)y[x]);
+        int partY;
+        if (logScale) {
+            partY = int(logScaling * log10f(float(y[x] + 1)));
+        } else {
+            partY = int(scaling * (float)y[x]);
+        }
 
         // Invert the y axis
         if (partY > partH - 1) {
@@ -150,9 +176,9 @@ QImage HistogramGenerator::drawComponent(const int *y, const QSize &size, const
 }
 
 void HistogramGenerator::drawComponentFull(QPainter *davinci, const int *y, const float &scaling, const QRect &rect, const QColor &color, int textSpace,
-                                           bool unscaled, uint max) const
+                                           bool unscaled, bool logScale, uint max)
 {
-    QImage component = drawComponent(y, rect.size() - QSize(0, textSpace), scaling, color, unscaled, max);
+    QImage component = drawComponent(y, rect.size() - QSize(0, textSpace), scaling, color, unscaled, logScale, max);
     davinci->drawImage(rect.topLeft(), component);
 
     uint min = 0;

src/scopes/colorscopes/histogramgenerator.h

@@ -12,6 +12,7 @@
 #define HISTOGRAMGENERATOR_H
 
 #include <QObject>
+#include "colorconstants.h"
 
 class QColor;
 class QImage;
@@ -25,21 +26,36 @@ class HistogramGenerator : public QObject
 public:
     explicit HistogramGenerator();
 
-    /** Recommendation to use.
-        See http://www.poynton.com/ColorFAQ.html for details. */
-    enum Rec { Rec_601, Rec_709 };
-
     /**
-        Calculates a histogram display from the input image.
-        components are OR-ed HistogramGenerator::Components flags and decide with components (Y, R, G, B) to paint.
-        unscaled = true leaves the width at 256 if the widget is wider (to avoid scaling). */
-    QImage calculateHistogram(const QSize &paradeSize, const QImage &image, const int &components, const HistogramGenerator::Rec rec, bool unscaled,
+     * Calculates a histogram display from the input image.
+     * @param paradeSize
+     * @param image
+     * @param components OR-ed HistogramGenerator::Components flags and decide with components (Y, R, G, B) to paint.
+     * @param rec
+     * @param unscaled unscaled = true leaves the width at 256 if the widget is wider (to avoid scaling).
+     * @param logScale Use a logarithmic instead of linear scale.
+     * @param accelFactor
+     * @return
+     */
+    QImage calculateHistogram(const QSize &paradeSize, const QImage &image, const int &components, const ITURec rec, bool unscaled,
+                              bool logScale,
                               uint accelFactor = 1) const;
 
-    QImage drawComponent(const int *y, const QSize &size, const float &scaling, const QColor &color, bool unscaled, uint max) const;
-
-    void drawComponentFull(QPainter *davinci, const int *y, const float &scaling, const QRect &rect, const QColor &color, int textSpace, bool unscaled,
-                           uint max) const;
+    /**
+     * Draws the histogram of a single component.
+     *
+     * @param y Bins containing the number of samples per value
+     * @param size Desired box size of the histogram
+     * @param scaling Use this scaling factor to scale the y values to the box height
+     * @param color Color to use for drawing
+     * @param unscaled Do not scale the width but take the number of bins instead (usually 256)
+     * @param logScale Use logarithmic scale instead of linear
+     * @param max Number of bins, usually 256
+     */
+    static QImage drawComponent(const int *y, const QSize &size, const float &scaling, const QColor &color, bool unscaled, bool logScale, uint max) ;
+
+    static void drawComponentFull(QPainter *davinci, const int *y, const float &scaling, const QRect &rect, const QColor &color, int textSpace,
+            bool unscaled, bool logScale, uint max) ;
 
     enum Components { ComponentY = 1 << 0, ComponentR = 1 << 1, ComponentG = 1 << 2, ComponentB = 1 << 3, ComponentSum = 1 << 4 };
 };

src/scopes/colorscopes/waveform.cpp

@@ -181,7 +181,7 @@ QImage Waveform::renderGfxScope(uint accelFactor, const QImage &qimage)
     timer.start();
 
     const int paintmode = m_ui->paintMode->itemData(m_ui->paintMode->currentIndex()).toInt();
-    WaveformGenerator::Rec rec = m_aRec601->isChecked() ? WaveformGenerator::Rec_601 : WaveformGenerator::Rec_709;
+    ITURec rec = m_aRec601->isChecked() ? ITURec::Rec_601 : ITURec::Rec_709;
     QImage wave = m_waveformGenerator->calculateWaveform(scopeRect().size() - m_textWidth - QSize(0, m_paddingBottom), qimage,
                                                          (WaveformGenerator::PaintMode)paintmode, true, rec, accelFactor);
 

src/scopes/colorscopes/waveformgenerator.cpp

@@ -9,6 +9,7 @@
  ***************************************************************************/
 
 #include "waveformgenerator.h"
+#include "colorconstants.h"
 
 #include <cmath>
 
@@ -25,7 +26,7 @@ WaveformGenerator::WaveformGenerator() = default;
 WaveformGenerator::~WaveformGenerator() = default;
 
 QImage WaveformGenerator::calculateWaveform(const QSize &waveformSize, const QImage &image, WaveformGenerator::PaintMode paintMode, bool drawAxis,
-                                            WaveformGenerator::Rec rec, uint accelFactor)
+                                            ITURec rec, uint accelFactor)
 {
     Q_ASSERT(accelFactor >= 1);
 
@@ -70,12 +71,12 @@ QImage WaveformGenerator::calculateWaveform(const QSize &waveformSize, const QIm
         double dY, dx, dy;
         auto *col = (const QRgb *)bits;
 
-        if (rec == WaveformGenerator::Rec_601) {
+        if (rec == ITURec::Rec_601) {
             // CIE 601 Luminance
-            dY = .299 * qRed(*col) + .587 * qGreen(*col) + .114 * qBlue(*col);
+            dY = REC_601_R * float(qRed(*col)) + REC_601_G * float(qGreen(*col)) + REC_601_B * float(qBlue(*col));
         } else {
             // CIE 709 Luminance
-            dY = .2125 * qRed(*col) + .7154 * qGreen(*col) + .0721 * qBlue(*col);
+            dY = REC_709_R * float(qRed(*col)) + REC_709_G * float(qGreen(*col)) + REC_709_B * float(qBlue(*col));
         }
         // dY is on [0,255] now.
 

src/scopes/colorscopes/waveformgenerator.h

@@ -12,6 +12,8 @@
 #define WAVEFORMGENERATOR_H
 
 #include <QObject>
+#include "colorconstants.h"
+
 class QImage;
 class QSize;
 
@@ -21,13 +23,12 @@ class WaveformGenerator : public QObject
 
 public:
     enum PaintMode { PaintMode_Green, PaintMode_Yellow, PaintMode_White };
-    enum Rec { Rec_601, Rec_709 };
 
     WaveformGenerator();
     ~WaveformGenerator() override;
 
     QImage calculateWaveform(const QSize &waveformSize, const QImage &image, WaveformGenerator::PaintMode paintMode, bool drawAxis,
-                             const WaveformGenerator::Rec rec, uint accelFactor = 1);
+                             const ITURec rec, uint accelFactor = 1);
 };
 
 #endif // WAVEFORMGENERATOR_H

src/ui/histogram_ui.ui

@@ -11,69 +11,143 @@
    </rect>
   </property>
   <layout class="QGridLayout" name="gridLayout">
-   <item row="0" column="1">
-    <widget class="QCheckBox" name="cbY">
-     <property name="toolTip">
-      <string>Luma value</string>
-     </property>
-     <property name="whatsThis">
-      <string/>
-     </property>
-     <property name="text">
-      <string>Y</string>
-     </property>
-    </widget>
-   </item>
-   <item row="0" column="3">
-    <widget class="QCheckBox" name="cbR">
-     <property name="text">
-      <string>R</string>
-     </property>
-    </widget>
-   </item>
-   <item row="0" column="4">
-    <widget class="QCheckBox" name="cbG">
-     <property name="text">
-      <string>G</string>
-     </property>
-    </widget>
-   </item>
-   <item row="0" column="5">
-    <widget class="QCheckBox" name="cbB">
-     <property name="text">
-      <string>B</string>
-     </property>
-    </widget>
-   </item>
-   <item row="1" column="1" colspan="5">
-    <spacer name="verticalSpacer">
-     <property name="orientation">
-      <enum>Qt::Vertical</enum>
-     </property>
-     <property name="sizeHint" stdset="0">
-      <size>
-       <width>20</width>
-       <height>40</height>
-      </size>
-     </property>
-    </spacer>
-   </item>
    <item row="0" column="0">
-    <widget class="QLabel" name="lblComponents">
-     <property name="text">
-      <string>Components</string>
-     </property>
-    </widget>
-   </item>
-   <item row="0" column="2">
-    <widget class="QCheckBox" name="cbS">
-     <property name="toolTip">
-      <string>RGB summed up</string>
-     </property>
-     <property name="text">
-      <string>Sum</string>
-     </property>
-    </widget>
+    <layout class="QVBoxLayout" name="verticalLayout">
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout_2">
+       <item>
+        <widget class="QLabel" name="lblComponents">
+         <property name="font">
+          <font>
+           <weight>75</weight>
+           <bold>true</bold>
+          </font>
+         </property>
+         <property name="text">
+          <string>Components</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QCheckBox" name="cbS">
+         <property name="toolTip">
+          <string>RGB summed up</string>
+         </property>
+         <property name="text">
+          <string>Sum</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QCheckBox" name="cbY">
+         <property name="toolTip">
+          <string>Luma value</string>
+         </property>
+         <property name="whatsThis">
+          <string/>
+         </property>
+         <property name="text">
+          <string>Y</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QCheckBox" name="cbR">
+         <property name="text">
+          <string>R</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QCheckBox" name="cbG">
+         <property name="text">
+          <string>G</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QCheckBox" name="cbB">
+         <property name="text">
+          <string>B</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <spacer name="horizontalSpacer_2">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>40</width>
+           <height>20</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+      </layout>
+     </item>
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout">
+       <item>
+        <widget class="QLabel" name="lblScale">
+         <property name="font">
+          <font>
+           <weight>75</weight>
+           <bold>true</bold>
+          </font>
+         </property>
+         <property name="text">
+          <string>Scale</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QRadioButton" name="rbLinear">
+         <property name="text">
+          <string>Linear</string>
+         </property>
+         <property name="checked">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QRadioButton" name="rbLogarithmic">
+         <property name="text">
+          <string>Logarithmic</string>
+         </property>
+        </widget>