[Insight-users] using NumericTraits in a templated function

[Dr. Roman Grothausmann]

Found the problem, a copy-paste remedy from the example, which had float hard 
coded. Works as expected now.

On 19/04/13 14:04, Dr. Roman Grothausmann wrote:
> Dear mailing list members,
>
>
> Is it possible to use NumericTraits in a templated function?
> E.g. using it like this:
>
> template<typename InputPixelType, size_t Dimension>
> int DoIt(int argc, char *argv[]){
>
> arg= argv[3];
> if (!strcmp(arg, "max")){
> printf("%s: identified as max\n", arg);
> th_l= itk::NumericTraits<InputPixelType>::max();
> std::cout << "Max: " << itk::NumericTraits< float >::max() << std::endl;
> }
> else if (!strcmp(arg, "min")){
> printf("%s: identified as min\n", arg);
> th_l= itk::NumericTraits<InputPixelType>::min();
> std::cout << "Min: " << itk::NumericTraits<InputPixelType>::min() << std::endl;
> std::cout << "Is -1 negative? " <<
> itk::NumericTraits<InputPixelType>::IsNegative(-1) << std::endl;
> std::cout << "Is 1 negative? " <<
> itk::NumericTraits<InputPixelType>::IsNegative(1) << std::endl;
> }
> else
> th_l= InputPixelType(atof(arg));
>
> ...
> calling it in main with:
>
> ...
> try
> {
> GetImageType(ifn, pixelType, componentType, dimensionType);
>
> switch (componentType)
> {
> case itk::ImageIOBase::UCHAR:{
> typedef unsigned char InputPixelType;
> switch (dimensionType){
> case 1:
> DoIt<InputPixelType, 1>(argc, argv);
> break;
> case 2:
> DoIt<InputPixelType, 2>(argc, argv);
> break;
> case 3:
> DoIt<InputPixelType, 3>(argc, argv);
> break;
> default:
> std::cout << "Images of dimension " << dimensionType << " are not supported!" <<
> std::endl;
> break;
> }
> break;
> }
> case itk::ImageIOBase::CHAR:{
> typedef char InputPixelType;
> switch (dimensionType){
> case 1:
> DoIt<InputPixelType, 1>(argc, argv);
> break;
> case 2:
> DoIt<InputPixelType, 2>(argc, argv);
> break;
> case 3:
> DoIt<InputPixelType, 3>(argc, argv);
> break;
> default:
> std::cout << "Images of dimension " << dimensionType << " are not supported!" <<
> std::endl;
> break;
> }
> break;
> }
> case itk::ImageIOBase::USHORT:{
> typedef unsigned short InputPixelType;
> switch (dimensionType){
> case 1:
> DoIt<InputPixelType, 1>(argc, argv);
> break;
> case 2:
> DoIt<InputPixelType, 2>(argc, argv);
> break;
> case 3:
> DoIt<InputPixelType, 3>(argc, argv);
> break;
> default:
> std::cout << "Images of dimension " << dimensionType << " are not supported!" <<
> std::endl;
> break;
> }
>
> break;
> }
> ...
>
>
> The program when run reports:
>
> Pixel Type is unsigned_short
> numDimensions: 3
> component size: 2
> pixel type (string): scalar
> pixel type: 1
> max: identified as max
> Max: 3.40282e+38
>
> I would expect Max to be 65535 for unsigned_short. Am I missing something or
> using it in an inappropriate way? If I use NumericTraits in a function that is
> not templated (e.g. as in
> http://itk.org/ITKExamples/Examples/Core/Common/GetTypeBasicInformation/GetTypeBasicInformation.html),
> it works as expected.
>
> Any help or hints are very much appreciated
> Roman
>

-- 
Dr. Roman Grothausmann

Tomographie und Digitale Bildverarbeitung
Tomography and Digital Image Analysis

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Medizinische Hochschule Hannover
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