How to quantify the difference between two image stacks?

Hi, I want to quantify the registration efficacy of two 3D image stacks. Is there a function that can quantify this? For now I have to do average projection of xy, yz, and xz plane and compare their absolute difference with imabsdiff. https://www.mathworks.com/help/images/ref/imabsdiff.html Thanks!

[Yajie Liang]

actually, the real question is how to quantify the quality of 3d image registration. For example, how much percentage of the volume is overlapped.

Answer 1

[Satwik]

Hi @Yajie Liang,

I believe that an in-built MATLAB function to determine percentage of volume overlapped between two images does not exist as of now. However, we can calculate the percentage volume overlapped between two 3D binary images by using the statistical method of Dice Similarity Coefficient (DSC). The DSC is calculated as twice the size of the intersection of the two sets divided by the sum of the sizes of the two sets.

Here is an example script you may refer to:

% Example binary 3D images (img1 and img2)
% Make sure these are logical arrays
img1 = rand(100, 100, 100) > 0.7;
img2 = rand(100, 100, 100) > 0.7;

% Calculate Dice Similarity Coefficient
intersection = sum((img1 & img2), 'all');
dsc = (2 * intersection) / (sum(img1, 'all') + sum(img2, 'all'));

% Convert to percentage
dsc_percentage = dsc * 100;

fprintf('Dice Similarity Coefficient: %.2f%%\n', dsc_percentage);

I hope this helps!