From: srit <srit>
Date: Thu, 17 Mar 2011 14:42:13 +0000 (+0000)
Subject: Romulo: changed rounding of image resampling to floor() because, from a clinical... 
X-Git-Tag: v1.2.0~163
X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=commitdiff_plain;h=dd96575fcb3e3af28160766907f68e34dfbf1ba2;p=clitk.git

Romulo: changed rounding of image resampling to floor() because, from a clinical point of view, it seems to be better to miss a slice than to add information that didn't exist in the original image.
---

diff --git a/itk/clitkResampleImageWithOptionsFilter.txx b/itk/clitkResampleImageWithOptionsFilter.txx
index df38d0e..1bf5448 100644
--- a/itk/clitkResampleImageWithOptionsFilter.txx
+++ b/itk/clitkResampleImageWithOptionsFilter.txx
@@ -122,13 +122,16 @@ GenerateOutputInformation()
   if (m_OutputIsoSpacing != -1) { // apply isoSpacing
     for(unsigned int i=0; i<dim; i++) {
       m_OutputSpacing[i] = m_OutputIsoSpacing;
-      // I use ceil to be sure not to miss a slice
-      m_OutputSize[i] = (int)ceil(inputSize[i]*inputSpacing[i]/m_OutputSpacing[i]);
+      // 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.
+      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++) {
-        m_OutputSize[i] = (int)ceil(inputSize[i]*inputSpacing[i]/m_OutputSpacing[i]);
+	// see comment above for the use of floor()
+	m_OutputSize[i] = (int)floor(inputSize[i]*inputSpacing[i]/m_OutputSpacing[i]);
       }
     } else {
       if (m_OutputSize[0] != 0) { // apply size, compute spacing