ENH: JIRA 362: BlockMatching application also supports a shift of the subsampled grid

Applications/DisparityMap/otbBlockMatching.cxx

@@ -240,6 +240,16 @@ private:
     SetDefaultParameterInt("bm.step",1);
     SetMinimumParameterIntValue("bm.step",1);
     MandatoryOff("bm.step");
+    
+    AddParameter(ParameterType_Int,"bm.startx","X start index");
+    SetParameterDescription("bm.startx","X start index of the subsampled grid (wrt the input image grid)");
+    SetDefaultParameterInt("bm.startx",0);
+    MandatoryOff("bm.startx");
+    
+    AddParameter(ParameterType_Int,"bm.starty","Y start index");
+    SetParameterDescription("bm.starty","Y start index of the subsampled grid (wrt the input image grid)");
+    SetDefaultParameterInt("bm.starty",0);
+    MandatoryOff("bm.starty");
 
     AddParameter(ParameterType_Group,"bm.medianfilter","Median filtering");
     SetParameterDescription("bm.medianfilter","Use a median filter to get a smooth disparity map");
@@ -357,6 +367,10 @@ private:
     int          minvdisp = GetParameterInt("bm.minvd");
     int          maxvdisp = GetParameterInt("bm.maxvd");
     unsigned int step     = GetParameterInt("bm.step");
+    
+    FloatImageType::IndexType gridIndex;
+    gridIndex[0] = GetParameterInt("bm.startx");
+    gridIndex[1] = GetParameterInt("bm.starty");
 
     std::ostringstream leftBandMathExpression;
     leftBandMathExpression<<"if(";
@@ -492,6 +506,7 @@ private:
       m_SSDBlockMatcher->SetRightInput(rightImage);
       m_SSDBlockMatcher->SetRadius(radius);
       m_SSDBlockMatcher->SetStep(step);
+      m_SSDBlockMatcher->SetGridIndex(gridIndex);
       m_SSDBlockMatcher->SetMinimumHorizontalDisparity(minhdisp);
       m_SSDBlockMatcher->SetMaximumHorizontalDisparity(maxhdisp);
       m_SSDBlockMatcher->SetMinimumVerticalDisparity(minvdisp);
@@ -557,6 +572,7 @@ private:
       m_NCCBlockMatcher->SetRightInput(rightImage);
       m_NCCBlockMatcher->SetRadius(radius);
       m_NCCBlockMatcher->SetStep(step);
+      m_NCCBlockMatcher->SetGridIndex(gridIndex);
       m_NCCBlockMatcher->SetMinimumHorizontalDisparity(minhdisp);
       m_NCCBlockMatcher->SetMaximumHorizontalDisparity(maxhdisp);
       m_NCCBlockMatcher->SetMinimumVerticalDisparity(minvdisp);
@@ -624,6 +640,7 @@ private:
       m_LPBlockMatcher->SetRightInput(rightImage);
       m_LPBlockMatcher->SetRadius(radius);
       m_LPBlockMatcher->SetStep(step);
+      m_LPBlockMatcher->SetGridIndex(gridIndex);
       m_LPBlockMatcher->GetFunctor().SetP(static_cast<double>(GetParameterFloat("bm.metric.lp.p")));
       m_LPBlockMatcher->SetMinimumHorizontalDisparity(minhdisp);
       m_LPBlockMatcher->SetMaximumHorizontalDisparity(maxhdisp);