QGIS » QGIS Application

Index: src/core/raster/qgsrasterlayer.cpp

===================================================================

--- src/core/raster/qgsrasterlayer.cpp	(revision 6434)

+++ src/core/raster/qgsrasterlayer.cpp	(working copy)

@@ -377,6 +377,10 @@

 dataProvider(0)

 {

+  userDefinedColorMinMax = false; //defaults needed to bypass stretch

+  userDefinedGrayMinMax = false;

+  setColorScalingAlgorithm(QgsRasterLayer::NO_STRETCH); //defaults needed to bypass stretch

+

   // Initialise the affine transform matrix

   adfGeoTransform[0] =  0;

   adfGeoTransform[1] =  1;

@@ -1335,7 +1339,7 @@

 void QgsRasterLayer::drawSingleBandGray(QPainter * theQPainter, QgsRasterViewPort * theRasterViewPort,                                                                             QgsMapToPixel * theQgsMapToPixel, int theBandNoInt)

 {

   QgsDebugMsg("QgsRasterLayer::drawSingleBandGray called for layer " + QString::number(theBandNoInt));

-  QgsRasterBandStats myRasterBandStats = getRasterBandStats(theBandNoInt);

+  //QgsRasterBandStats myRasterBandStats = getRasterBandStats(theBandNoInt);

   GDALRasterBand *myGdalBand = gdalDataset->GetRasterBand(theBandNoInt);

   GDALDataType myDataType = myGdalBand->GetRasterDataType();

   void *myGdalScanData = readData ( myGdalBand, theRasterViewPort );

@@ -1345,34 +1349,85 @@

   myQImage.setAlphaBuffer(true);

   myQImage.fill(qRgba(255,255,255,0 )); // fill transparent

-  double myRangeDouble = myRasterBandStats.rangeDouble;

+  //double myRangeDouble = myRasterBandStats.rangeDouble;

+  QgsRasterBandStats myGrayBandStats;

+  /*

+   * If stDevsToPlotDouble is set it will override any user defined Min Max values

+   */

+  if(QgsRasterLayer::NO_STRETCH != getColorScalingAlgorithm() && (!userDefinedGrayMinMax || stdDevsToPlotDouble > 0))

+  {

+    myGrayBandStats = getRasterBandStats(theBandNoInt);

+    /*

+     * This may upset some, but these values are set directly so that the userDefinedColorMinMax variable is not set, 

+     * though it really does not matter by this point.

+     */

+    if(stdDevsToPlotDouble > 0)

+    {

+      minGrayDouble = myGrayBandStats.meanDouble - (stdDevsToPlotDouble * myGrayBandStats.stdDevDouble);

+      maxGrayDouble = myGrayBandStats.meanDouble + (stdDevsToPlotDouble * myGrayBandStats.stdDevDouble);

+    }

+    else 

+    {

+      minGrayDouble = myGrayBandStats.minValDouble;

+      maxGrayDouble = myGrayBandStats.maxValDouble;

+    }

+  }

+  

+  /*

+   * Check for invalid min max value based on GDALDataType.

+   * Invalid values can happen if the user uses stdDevs to set min and max

+   * TODO:Needs to be expanded for all GDALDataTypes

+   */

+  if(GDT_Byte == myDataType)

+  {

+    if(minGrayDouble < 0.0)

+      minGrayDouble = 0.0;

+    if(maxGrayDouble > 255.0)

+      maxGrayDouble = 255.0;

+  }

+

   // print each point in myGdalScanData with equal parts R, G ,B o make it show as gray

   for (int myColumnInt = 0; myColumnInt < theRasterViewPort->drawableAreaYDimInt; ++myColumnInt)

   {

     for (int myRowInt = 0; myRowInt < theRasterViewPort->drawableAreaXDimInt; ++myRowInt)

     {

-      double myGrayValDouble = readValue ( myGdalScanData, myDataType,

+      double myGrayValueDouble = readValue ( myGdalScanData, myDataType,

           myColumnInt * theRasterViewPort->drawableAreaXDimInt + myRowInt );

       // If noDataValueDouble is 'nan', the comparison

       // against myGrayValDouble will always fail ( nan==nan always

       // returns false, by design), hence the slightly odd comparison

       // of myGrayValDouble against itself. 

-      if ( myGrayValDouble == noDataValueDouble ||

-          myGrayValDouble != myGrayValDouble)

+      if ( myGrayValueDouble == noDataValueDouble ||

+          myGrayValueDouble != myGrayValueDouble)

       {

         myQImage.setPixel(myRowInt, myColumnInt, qRgba(255,255,255,0 ));

         continue;

       }

-      int myGrayValInt = static_cast < int >( (myGrayValDouble-myRasterBandStats.minValDouble)

-          * (255/myRangeDouble));

+      if(QgsRasterLayer::NO_STRETCH != getColorScalingAlgorithm())

+      {

+        if(QgsRasterLayer::CLIP_TO_MINMAX == getColorScalingAlgorithm() || QgsRasterLayer::STRETCH_AND_CLIP_TO_MINMAX == getColorScalingAlgorithm())

+          if(myGrayValueDouble < minGrayDouble || myGrayValueDouble > maxGrayDouble) continue;

+        if(QgsRasterLayer::STRETCH_TO_MINMAX == getColorScalingAlgorithm() || QgsRasterLayer::STRETCH_AND_CLIP_TO_MINMAX == getColorScalingAlgorithm())

+          myGrayValueDouble = ((myGrayValueDouble - minGrayDouble)/(maxGrayDouble - minGrayDouble))*255;

+

+        //Check for out of range pixel values

+        if(myGrayValueDouble < 0.0)

+          myGrayValueDouble = 0.0;

+        else if(myGrayValueDouble > 255.0)

+          myGrayValueDouble = 255.0;

+      }

+

+      int myGrayValInt = static_cast < int > ( myGrayValueDouble);

+      //int myGrayValInt = static_cast < int >( (myGrayValDouble-myRasterBandStats.minValDouble) * (255/myRangeDouble));

+

       if (invertHistogramFlag)

       {

-        myGrayValDouble = 255 - myGrayValDouble;

+        myGrayValInt = 255 - myGrayValInt;

       }

       myQImage.setPixel(myRowInt, myColumnInt, qRgba(myGrayValInt, myGrayValInt, myGrayValInt, mTransparencyLevel));

     }

@@ -2235,6 +2290,80 @@

   //myQImage.fill(0);

   myQImage.setAlphaBuffer(true);

   myQImage.fill(qRgba(255,255,255,0 )); // fill transparent

+

+  QgsRasterBandStats myRedBandStats;

+  QgsRasterBandStats myGreenBandStats;

+  QgsRasterBandStats myBlueBandStats;

+  /*

+   * If a stetch is requested and there are no user defined Min Max values

+   * we need to get these values from the bands themselves.

+   * If stDevsToPlotDouble is set it will override any user defined Min Max values

+   *

+   * NOTE: If the user only set minRedDouble this next block would be skipped 

+   * and all the other variables could have garbage (they are not initialized in the constructor) 

+   * This may want to be updated so that each Min Max is check to be sure it was set and if one is missing

+   * the get the QgsRasterBandStats for that band.

+   */

+  if(QgsRasterLayer::NO_STRETCH != getColorScalingAlgorithm() && (!userDefinedColorMinMax || stdDevsToPlotDouble > 0))

+  {

+    myRedBandStats = getRasterBandStats(myRedBandNoInt);

+    myGreenBandStats = getRasterBandStats(myGreenBandNoInt);

+    myBlueBandStats = getRasterBandStats(myBlueBandNoInt);

+

+    /*

+     * This may upset some, but these values are set directly so that the userDefinedColorMinMax variable is not set, 

+     * though it really does not matter at this point. Also insignificantly faster.

+     */

+    if(stdDevsToPlotDouble > 0)

+    {

+      minRedDouble = myRedBandStats.meanDouble - (stdDevsToPlotDouble * myRedBandStats.stdDevDouble);

+      maxRedDouble = myRedBandStats.meanDouble + (stdDevsToPlotDouble * myRedBandStats.stdDevDouble);

+      minGreenDouble = myGreenBandStats.meanDouble - (stdDevsToPlotDouble * myGreenBandStats.stdDevDouble);

+      maxGreenDouble = myGreenBandStats.meanDouble + (stdDevsToPlotDouble * myGreenBandStats.stdDevDouble);

+      minBlueDouble = myBlueBandStats.meanDouble - (stdDevsToPlotDouble * myBlueBandStats.stdDevDouble);

+      maxBlueDouble = myBlueBandStats.meanDouble + (stdDevsToPlotDouble * myBlueBandStats.stdDevDouble);

+    }

+    else 

+    {

+      minRedDouble = myRedBandStats.minValDouble;

+      maxRedDouble = myRedBandStats.maxValDouble;

+      minGreenDouble = myGreenBandStats.minValDouble;

+      maxGreenDouble = myGreenBandStats.maxValDouble;

+      minBlueDouble = myBlueBandStats.minValDouble;

+      maxBlueDouble = myBlueBandStats.maxValDouble;

+    }

+  }

+

+  /*

+   * Check for invalid min max value based on GDALDataType.

+   * Invalid values can happen if the user uses stdDevs to set min and max

+   * TODO:Needs to be expanded for all GDALDataTypes

+   */

+  if(GDT_Byte == myRedType)

+  {

+    if(minRedDouble < 0.0)

+      minRedDouble = 0.0;

+    if(maxRedDouble > 255.0)

+      maxRedDouble = 255.0;

+  }

+

+  if(GDT_Byte == myGreenType)

+  {

+    if(minGreenDouble < 0.0)

+      minGreenDouble = 0.0;

+    if(maxGreenDouble > 255.0)

+      maxGreenDouble = 255.0;

+  }

+

+  if(GDT_Byte == myBlueType)

+  {

+    if(minBlueDouble < 0.0)

+      minBlueDouble = 0.0;

+    if(maxBlueDouble > 255.0)

+      maxBlueDouble = 255.0;

+  }

+

+  //Read and display pixels

   for (int myColumnInt = 0; myColumnInt < theRasterViewPort->drawableAreaYDimInt; ++myColumnInt)

   {

     for (int myRowInt = 0; myRowInt < theRasterViewPort->drawableAreaXDimInt; ++myRowInt)

@@ -2263,6 +2392,44 @@

         continue;

       }

+      /*

+       * Stretch RBG values based on selected color scaling algoritm

+       * NOTE: NO_STRETCH enum will help eliminte the need to call QgsRasterBandStats when an image is initially loaded

+       */

+      

+      if(QgsRasterLayer::NO_STRETCH != getColorScalingAlgorithm())

+      {

+        /*

+         * Currently if any one band is outside of min max range for the band the pixel is discarded,

+         * this can easily be updated so that all band have to be ouside of the min max range

+         */

+        if(QgsRasterLayer::CLIP_TO_MINMAX == getColorScalingAlgorithm() || QgsRasterLayer::STRETCH_AND_CLIP_TO_MINMAX == getColorScalingAlgorithm())

+        {

+          if(myRedValueDouble < minRedDouble || myRedValueDouble > maxRedDouble) continue;

+          if(myGreenValueDouble < minRedDouble || myGreenValueDouble > maxRedDouble) continue;

+          if(myBlueValueDouble < minBlueDouble || myBlueValueDouble > maxBlueDouble) continue;

+        }

+        if(QgsRasterLayer::STRETCH_TO_MINMAX == getColorScalingAlgorithm() || QgsRasterLayer::STRETCH_AND_CLIP_TO_MINMAX == getColorScalingAlgorithm())

+        {

+          myRedValueDouble = ((myRedValueDouble - minRedDouble)/(maxRedDouble - minRedDouble))*255;

+          myGreenValueDouble = ((myGreenValueDouble - minGreenDouble)/(maxGreenDouble - minGreenDouble))*255;

+          myBlueValueDouble = ((myBlueValueDouble - minBlueDouble)/(maxBlueDouble - minBlueDouble))*255;

+        }

+        //Check for out of range pixel values

+        if(myRedValueDouble < 0.0)

+          myRedValueDouble = 0.0;

+        else if(myRedValueDouble > 255.0)

+          myRedValueDouble = 255.0;

+        if(myGreenValueDouble < 0.0)

+          myGreenValueDouble = 0.0;

+        else if(myGreenValueDouble > 255.0)

+          myGreenValueDouble = 255.0;

+        if(myBlueValueDouble < 0.0)

+          myBlueValueDouble = 0.0;

+        else if(myBlueValueDouble > 255.0)

+          myBlueValueDouble = 255.0;

+      }

+

       int myRedValueInt   = static_cast < int > ( myRedValueDouble );

       int myGreenValueInt = static_cast < int > ( myGreenValueDouble );

       int myBlueValueInt  = static_cast < int > ( myBlueValueDouble );

@@ -2273,6 +2440,7 @@

         myGreenValueInt = 255 - myGreenValueInt;

         myBlueValueInt = 255 - myBlueValueInt;

       }

+

       //set the pixel based on the above color mappings

       myQImage.setPixel ( myRowInt, myColumnInt,

           qRgba(myRedValueInt, myGreenValueInt, myBlueValueInt, mTransparencyLevel) );

@@ -2315,7 +2483,7 @@

         / theQgsMapToPixel->mapUnitsPerPixel() 

         * fabs(adfGeoTransform[5])

         ); 

-  }                                   

+  }

   QgsDebugMsg("QgsRasterLayer::drawSingleBandGray: painting image to canvas from source NW"\

       + QString::number(paintXoffset) + ", " + QString::number(paintYoffset)\

Index: src/core/raster/qgsrasterlayer.h

===================================================================

--- src/core/raster/qgsrasterlayer.h	(revision 6434)

+++ src/core/raster/qgsrasterlayer.h	(working copy)

@@ -460,6 +460,7 @@

      * that falls outside the clipping range.*/

     void setMinRedDouble(double theDouble)

     {

+        userDefinedColorMinMax = true;

         minRedDouble=theDouble;

     };

     /** \brief Accessor for maximum clipping range for red.

@@ -478,6 +479,7 @@

      * that falls outside the clipping range.*/

     void setMaxRedDouble(double theDouble)

     {

+        userDefinedColorMinMax = true;

         maxRedDouble=theDouble;

     };

     // 

@@ -499,6 +501,7 @@

      * that falls outside the clipping range.*/

     void setMinGreenDouble(double theDouble)

     {

+        userDefinedColorMinMax = true;

         minGreenDouble=theDouble;

     };

     /** \brief Accessor for maximum clipping range for green.

@@ -517,6 +520,7 @@

      * that falls outside the clipping range.*/

     void setMaxGreenDouble(double theDouble)

     {

+        userDefinedColorMinMax = true;

         maxGreenDouble=theDouble;

     };

     // 

@@ -539,6 +543,7 @@

      * that falls outside the clipping range.*/

     void setMinBlueDouble(double theDouble)

     {

+        userDefinedColorMinMax = true;

         minBlueDouble=theDouble;

     };

     /** \brief Accessor for maximum clipping range for blue.

@@ -557,6 +562,7 @@

      * that falls outside the clipping range.*/

     void setMaxBlueDouble(double theDouble)

     {

+        userDefinedColorMinMax = true;

         maxBlueDouble=theDouble;

     };

     // 

@@ -578,6 +584,7 @@

      * that falls outside the clipping range.*/

     void setMinGrayDouble(double theDouble)

     {

+        userDefinedGrayMinMax = true;

         minGrayDouble=theDouble;

     };

     /** \brief Accessor for maximum clipping range for gray.

@@ -596,12 +603,14 @@

      * that falls outside the clipping range.*/

     void setMaxGrayDouble(double theDouble)

     {

+        userDefinedGrayMinMax = true;

         maxGrayDouble=theDouble;

     };

     //

     /** \brief This enumerator describes the types of histogram scaling algorithms that can be used.  */

     enum COLOR_SCALING_ALGORITHM

     {

+        NO_STRETCH, //this should be the default color scaling algorithm, will allow for the display of images without calling QgsRasterBandStats unless needed

         STRETCH_TO_MINMAX, //linear histogram stretch

         STRETCH_AND_CLIP_TO_MINMAX,

         CLIP_TO_MINMAX

@@ -998,6 +1007,9 @@

     double maxGrayDouble;

     /** \brief Whether this raster has overviews / pyramids or not */

     bool hasPyramidsFlag;

+    //Since QgsRasterBandStats deos not set the minRedDouble maxRedDouble etc., it is benificial to know if the user as set these values. Default = false

+    bool userDefinedColorMinMax;

+    bool userDefinedGrayMinMax;

     /** \brief This list holds a series of RasterPyramid structs

      * which store infomation for each potential pyramid level for this raster.*/

     RasterPyramidList mPyramidList;