Yes, thanks for pointing out the ambiguity in the original question and for your time helping with this! … I’ll use an example with what I have in ImageJ to make it as concrete as possible. I think you summarized it well with “I suppose that you intend to get an image having in each pixel the corresponding color in the heatmap.”
I have two images with custom color mapping applied by making an interpolated LUT from black to the max RGB color value using ImageJ’s LUT Editor, similar to the gradient created with e.g. cgrad(:black, pal[1]):
And a composite made using the Merge Channels… tool:
(Have not settled on these colors as final choices)
How can I achieve a similar effect in Julia? That is, apply a custom LUT/gradient from black to a custom color choice (if not using cgrad, then is there some other way?) to each image, then blending the images (with ImageJ, it looks like simple RGB addition).