[vtkusers] LUT: gray scale to RGB

[Luis Roberto P. Paula]

Hi All,

I have an image in gray scale. In this image, there are just three possible
values: 0, 50 and 100.

I need to set 50 to red and 100 to green, so I have created the following
lookup table:

   vtkLookupTable *lut = vtkLookupTable::New();
   lut->SetNumberOfColors(101);
   lut->SetTableValue(0,0,0,0,0);
   lut->SetTableValue(50,1,0,0,1);
   lut->SetTableValue(100,0,1,0,1);
   lut->Build();

And here I'm using converting this image to RGB:

   vtkImageMapToColors *img1_rgb = vtkImageMapToColors::New();
   img1_rgb->SetInput(img_grey);
   img1_rgb->SetLookupTable(lut);
   img1_rgb->SetOutputFormatToRGBA();
   img1_rgb->Update();

The problem is that the pixels with values 50 and 100 are always being
converted to green, with the same intensity.

Does anyone know what I'm doing wrong?

Thanks & Regards,
Luis
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