Setting transparency for overlaying images

Question

Amadeus 2013-2-16

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/63752-setting-transparency-for-overlaying-images

Hi,

I am trying to overlay an image onto another. Currently I am using the following code however the problem is that, my transparency is always the same (0.75) for all images. However I need to have image specific transparency value. For example for that image, if I2 is more dominant then it should be seen dominant. But if I1 is dominant, then I2 should be seen more transparent. (I guess I need to set something like AlphaData but?)

I hope I could explain what I need. I will be very grateful if you can help me.

Regards, Amadeus

Here is the code:

 for slicenum = 1 : size(nii.img,3)
      I1 = nii.img(:,:,slicenum);
      I2 = uint16(M(:,:,slicenum));
      RGB2=ind2rgb(I2,colormap(hot));
      figure,imshow(I1,[]);
      hold on; h = imshow(RGB2);
      alpha(0.75);
      save_file_name = strcat(num2str(slicenum),'.jpg');
      saveas(gcf,save_file_name);
      pause(0.25)
end

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Answer 1

Image Analyst 2013-2-17

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https://ww2.mathworks.cn/matlabcentral/answers/63752-setting-transparency-for-overlaying-images#answer_75324

在 MATLAB Online 中打开

See Steve's blog: http://blogs.mathworks.com/steve/2009/02/18/image-overlay-using-transparency/ Note how he changes the transparency as a function of location. Steve says:

"Using image data to control transparency
My second transparency example gets a bit more creative. I'll display an image that's a solid color, but I'll use another data set to vary the solid color image's transparency on a pixel-by-pixel basis. "

which sounds like it's exactly what you want to do.