[ITK-users] How to add two RGB images?

[Alberto Bert]

Hi all,

I have got an grey level image and a binary segmentation mask extracted from it, and I would like to produce a third image, showing the segmented area in color on top the original grey level image.

Here is what I am doing:

image_rgb = sitk.ScalarToRGBColormap(image, colormap = sitk.ScalarToRGBColormapImageFilter.Grey)
mask_rgb = sitk.ScalarToRGBColormap(mask, colormap = sitk.ScalarToRGBColormapImageFilter.Red)
mask_overlay = image_rgb + mask_rgb

Unfortunately, mask_overlay looks just the same as image_rgb, as the addition were not doing any action.

Any help will be appreciated,
Thanks,

Alberto

PS
I am using SimpleITK 0.9.1 and Python 2.7

PPS
I have already tried the LabelOverlayImageFilter. In fact that was my first choice, but I cannot make it working either (see my previous email, please).