[Insight-users] problem with RGB .bmp images

[John]

Luis Ibanez <luis.ibanez at ...> writes:

> 
> 
> Hi John,
> 
> Are you declaring your image as an image whose
> pixel type is itkRGBPixel<>  ?
> 
> Please provide a minimal code snippet illustrating your problem.
> 
>     Thanks
> 
>        Luis

Hi Luis,

Of course I declared the pixel type as itk::RGBPixel.

To verify that it is not an error of my code I took the example from
Examples/DataRepresentation/Image/RGBImage.cxx.

The following code results for the image http://jperl.gu6.info/000.bmp
in the output:

Pixel values from GetRed,GetGreen,GetBlue:
Red = 137
Green = 137
Blue = 137
Pixel values:
Red = 137
Green = 137
Blue = 137

Here the code I used:

#include "itkImage.h"
#include "itkImageFileReader.h"

#include "itkRGBPixel.h"

int main( int , char * argv[] )
{
  typedef itk::RGBPixel< unsigned char >    PixelType;
  typedef itk::Image< PixelType, 2 >   ImageType;
  typedef itk::ImageFileReader< ImageType >  ReaderType;
  
  ReaderType::Pointer reader = ReaderType::New();
  reader->SetFileName( argv[1] );
  reader->Update();

  ImageType::Pointer image = reader->GetOutput();

  ImageType::IndexType pixelIndex;

  pixelIndex[0] = 90;
  pixelIndex[1] = 435;

  PixelType onePixel = image->GetPixel( pixelIndex );
  
  PixelType::ValueType red   = onePixel.GetRed();
  PixelType::ValueType green = onePixel.GetGreen();
  PixelType::ValueType blue  = onePixel.GetBlue();

  std::cout << "Pixel values from GetRed,GetGreen,GetBlue:" 
<< std::endl;
  std::cout << "Red = " 
      << itk::NumericTraits<PixelType::ValueType>::PrintType(red)
      << std::endl;
  std::cout << "Green = "
      << itk::NumericTraits<PixelType::ValueType>::PrintType(green)
      << std::endl;
  std::cout << "Blue = "
      << itk::NumericTraits<PixelType::ValueType>::PrintType(blue)
      << std::endl;

  red   = onePixel[0];  // extract Red   component
  green = onePixel[1];  // extract Green component
  blue  = onePixel[2];  // extract Blue  component

  std::cout << "Pixel values:" << std::endl;
  std::cout << "Red = "
      << itk::NumericTraits<PixelType::ValueType>::PrintType(red)
      << std::endl;
  std::cout << "Green = "
      << itk::NumericTraits<PixelType::ValueType>::PrintType(green)
      << std::endl;
  std::cout << "Blue = "
      << itk::NumericTraits<PixelType::ValueType>::PrintType(blue)
      << std::endl;
 
  return 0;
}

I tried the above code on linux and windows with the same result.
Hope this helps you.

John