BUG: compute gradient in index space since resolution is not read from image

Code/FeatureExtraction/otbGenericRoadExtractionFilter.h

@@ -187,7 +187,9 @@ protected:
   /** Destructor */
   ~GenericRoadExtractionFilter() {}
 
-  /** Prepare main computation method */
+  /** Prepare main computation method
+   *  Note : this function isn't called
+   */
   void BeforeGenerateData(void);
 
   /** Main computation method */

Code/FeatureExtraction/otbGenericRoadExtractionFilter.txx

@@ -113,6 +113,7 @@ GenericRoadExtractionFilter<TInputImage, TOutputPath>
   m_GradientFilter->SetInput(m_SquareRootImageFilter->GetOutput());
   /** Sigma calculated with the alpha and image resolution parameters */
   m_GradientFilter->SetSigma(static_cast<SigmaType>(m_Alpha * (1.2 / m_Resolution + 1.)));
+  m_GradientFilter->SetUseImageDirection(false);
 
   m_NeighborhoodScalarProductFilter->SetInput(m_GradientFilter->GetOutput());