ENH: the application resample rainfall time series using bicubic interpolation (spatial)

app/otbTimeSeriesIndexTrend.cxx

@@ -146,6 +146,8 @@ private:
       {
       p[i] = i*2;
       }
+//    p = {65,63,67,64,68,62,70,66,68,67,69,71};
+//    Y = [68,66,68,65,69,66,68,65,71,67,68,70]
     std::cout << f(p) << std::endl;
   }
 
@@ -476,7 +478,7 @@ private:
         m_ResampleFilter = ResampleImageFilterType::New();
         m_ResampleFilter->SetInput(m_RFCumulReduceFilter->GetOutput());
         m_ResampleFilter->SetOutputOrigin(m_NDVIConcatener->GetOutput()->GetOrigin());
-        m_ResampleFilter->SetOutputSpacing(m_NDVIConcatener->GetOutput()->GetSpacing());
+        m_ResampleFilter->SetOutputSpacing(m_NDVIConcatener->GetOutput()->GetSignedSpacing());
         m_ResampleFilter->SetOutputSize(m_NDVIConcatener->GetOutput()->GetLargestPossibleRegion().GetSize());
         m_ResampleFilter->SetInterpolator(linInterpolator);
 
@@ -490,7 +492,7 @@ private:
         // Compute residues
         m_ResiduesFilter = ResiduesFilterType::New();
         m_ResiduesFilter->SetInput1(reducedNDVI);
-        m_ResiduesFilter->SetInput2(m_RFCumulReduceFilter->GetOutput());
+        m_ResiduesFilter->SetInput2(m_ResampleFilter->GetOutput());
 
         // Output residues
         if (HasValue("residues"))
@@ -519,7 +521,7 @@ private:
         // Correlation between NDVI and Rainfall
         m_CorrelationFilter = PearsonCorrelationFilterType::New();
         m_CorrelationFilter->SetInput1(reducedNDVI);
-        m_CorrelationFilter->SetInput2(m_RFCumulReduceFilter->GetOutput());
+        m_CorrelationFilter->SetInput2(m_ResampleFilter->GetOutput());
 
         if (HasValue("pearsoncoef"))
           {