How to speed itk::RescaleIntensityImageFilter ?

typedef  signed short InputPixelType;
typedef  unsigned char OutputPixelType;

typedef itk::Image<InputPixelType, 3> InputImageType;
typedef itk::Image<OutputPixelType, 3> OutputImageType;

using RescaleFilterType =
			itk::RescaleIntensityImageFilter<InputImageType, OutputImageType>;
		RescaleFilterType::Pointer rescaler = RescaleFilterType::New();

when i convert the 3D data from signed short to unsigned char, it consume too much time and compute, how I can to speed it.?

If you don’t call filter->Update(); explicitly, it is called during rescaler->Update();. This will cause the appearance of rescaler using a lot of time and memory. For slowness, make sure you are running in release mode, not debug.