From 909125a84e0cd7af31f1bf95dbd7816656765d81 Mon Sep 17 00:00:00 2001
From: Simon Rit <simon.rit@creatis.insa-lyon.fr>
Date: Fri, 17 Jun 2011 18:40:45 +0200
Subject: [PATCH] Resample is not robust to i/o spacings with different signs
 => launch exception

---
 itk/clitkResampleImageWithOptionsFilter.txx | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/itk/clitkResampleImageWithOptionsFilter.txx b/itk/clitkResampleImageWithOptionsFilter.txx
index 7e5eeab..36e08bf 100644
--- a/itk/clitkResampleImageWithOptionsFilter.txx
+++ b/itk/clitkResampleImageWithOptionsFilter.txx
@@ -125,11 +125,15 @@ GenerateOutputInformation()
       // floor() is used to intentionally reduce the number of slices 
       // because, from a clinical point of view, it's better to 
       // remove data than to add data that privously didn't exist.
+      if(inputSpacing[i]*m_OutputSpacing[i]<0)
+        itkExceptionMacro( << "Input and output spacings don't have the same size, can't cope with that" );
       m_OutputSize[i] = (int)floor(inputSize[i]*inputSpacing[i]/m_OutputSpacing[i]);
     }
   } else {
     if (m_OutputSpacing[0] != -1) { // apply spacing, compute size
       for(unsigned int i=0; i<dim; i++) {
+        if(inputSpacing[i]*m_OutputSpacing[i]<0)
+          itkExceptionMacro( << "Input and output spacings don't have the same size, can't cope with that" );
 	// see comment above for the use of floor()
 	m_OutputSize[i] = (int)floor(inputSize[i]*inputSpacing[i]/m_OutputSpacing[i]);
       }
@@ -151,7 +155,7 @@ GenerateOutputInformation()
     m_OutputSize[l] = inputSize[l];
     m_OutputSpacing[l] = inputSpacing[l];
   }
-    
+
   // Set Size/Spacing
   OutputImagePointer outputImage = this->GetOutput(0);
   // OutputImageRegionType region;
-- 
2.45.1