ENH: Replace "vnl_sample.h" with <random> in VoronoiSegmentation tests

Modules/Segmentation/Voronoi/test/itkVoronoiSegmentationImageFilterTest.cxx

@@ -19,6 +19,7 @@
 #include "itkVoronoiSegmentationImageFilter.h"
 #include "itkVoronoiSegmentationImageFilterBase.h"
 #include "itkTestingMacros.h"
+#include <random> // For mt19937.
 
 int
 itkVoronoiSegmentationImageFilterTest(int argc, char * argv[])
@@ -53,26 +54,31 @@ itkVoronoiSegmentationImageFilterTest(int argc, char * argv[])
   inputImage->SetRegions(region);
   inputImage->Allocate();
 
+  std::mt19937 randomNumberEngine{};
 
   itk::ImageRegionIteratorWithIndex<UShortImage> it(inputImage, region);
 
   // Background: random field with mean: 500, std: 50
+  std::uniform_int_distribution<unsigned short> backgroundRandomNumberDistribution(450, 550);
+
   std::cout << "Setting background random pattern image" << std::endl;
   while (!it.IsAtEnd())
   {
-    it.Set(static_cast<unsigned short>(vnl_sample_uniform(450, 550)));
+    it.Set(backgroundRandomNumberDistribution(randomNumberEngine));
     ++it;
   }
 
   // Object (2): random field with mean: 520, std: 20
+  std::uniform_int_distribution<unsigned short> forgroundRandomNumberDistribution(500, 540);
+
   std::cout << "Defining object #2" << std::endl;
   for (unsigned int i = 30; i < 94; ++i)
   {
     index[0] = i;
     for (unsigned int j = 30; j < 94; ++j)
     {
       index[1] = j;
-      inputImage->SetPixel(index, static_cast<unsigned short>(vnl_sample_uniform(500, 540)));
+      inputImage->SetPixel(index, forgroundRandomNumberDistribution(randomNumberEngine));
     }
   }
 
@@ -82,7 +88,7 @@ itkVoronoiSegmentationImageFilterTest(int argc, char * argv[])
     for (unsigned int j = 150; j < 214; ++j)
     {
       index[1] = j;
-      inputImage->SetPixel(index, static_cast<unsigned short>(vnl_sample_uniform(500, 540)));
+      inputImage->SetPixel(index, forgroundRandomNumberDistribution(randomNumberEngine));
     }
   }
 

Modules/Segmentation/Voronoi/test/itkVoronoiSegmentationRGBImageFilterTest.cxx

@@ -23,9 +23,11 @@
 
 #include <algorithm> // For generate.
 #include <iostream>
+#include <random> // For mt19937.
 
 // type alias for all functions
 using PixelType = itk::RGBPixel<unsigned char>;
+using PixelComponentType = PixelType::ComponentType;
 using ImageType = itk::Image<PixelType, 2>;
 using SegmentationType = itk::Image<unsigned char, 2>;
 using ReaderType = itk::ImageFileReader<ImageType>;
@@ -69,19 +71,25 @@ SetUpInputImage()
   inputImage->SetRegions(region);
   inputImage->Allocate();
 
+  std::mt19937 randomNumberEngine{};
+
   // add background random field
+  std::uniform_int_distribution<> backgroundRandomNumberDistribution(bgMean - bgStd, bgMean + bgStd);
+
   itk::ImageRegionIterator<ImageType> iter(inputImage, region);
   while (!iter.IsAtEnd())
   {
     PixelType px;
-    std::generate(px.begin(), px.end(), [] {
-      return static_cast<unsigned char>(vnl_sample_uniform(bgMean - bgStd, bgMean + bgStd));
+    std::generate(px.begin(), px.end(), [&randomNumberEngine, &backgroundRandomNumberDistribution] {
+      return static_cast<PixelComponentType>(backgroundRandomNumberDistribution(randomNumberEngine));
     });
     iter.Set(px);
     ++iter;
   }
 
   // add objects to image
+  std::uniform_int_distribution<> forgroundRandomNumberDistribution(fgMean - fgStd, fgMean + fgStd);
+
   for (unsigned int x = objAStartX; x < objAEndX; ++x)
   {
     for (unsigned int y = objAStartY; y < objAEndY; ++y)
@@ -91,8 +99,8 @@ SetUpInputImage()
       idx[1] = y;
 
       PixelType px;
-      std::generate(px.begin(), px.end(), [] {
-        return static_cast<unsigned char>(vnl_sample_uniform(fgMean - fgStd, fgMean + fgStd));
+      std::generate(px.begin(), px.end(), [&randomNumberEngine, &forgroundRandomNumberDistribution] {
+        return static_cast<PixelComponentType>(forgroundRandomNumberDistribution(randomNumberEngine));
       });
       inputImage->SetPixel(idx, px);
     }
@@ -106,8 +114,8 @@ SetUpInputImage()
       idx[1] = y;
 
       PixelType px;
-      std::generate(px.begin(), px.end(), [] {
-        return static_cast<unsigned char>(vnl_sample_uniform(fgMean - fgStd, fgMean + fgStd));
+      std::generate(px.begin(), px.end(), [&randomNumberEngine, &forgroundRandomNumberDistribution] {
+        return static_cast<PixelComponentType>(forgroundRandomNumberDistribution(randomNumberEngine));
       });
       inputImage->SetPixel(idx, px);
     }