Batch processing images from 2 folders and saving them to another folder

Hello, I have two folders, Folder A and Folder B with unit8 binary images of same corresponding file names.

The folder structure is as follows:

Folder A
    Image 1.bmp
    Image 2.bmp
    Image 3.bmp
    ...
    
Folder B
    Image 1.bmp
    Image 2.bmp
    Image 3.bmp
    ...

I want to perform a simple operation imsubtract between the same filenames in the two folders. For example, (Image 1 from Folder A) - (Image 1 from Folder B). Similary (Image 2 from Folder A) - (Image 2 from Folder B), and so on. I want to batch process these, and save it to a different folder (e.g. Folder C). How would I go about doing this?

I have 400 images in Folder A and 400 images in Folder B with the same corresponding filenames. I want to batch export calculated 400 files (in for e.g. Folder C). Any help is very appreciated.

Answer 1

[Image Analyst]

Do you want floating point differences? Positive and negative values allowed? Or do you want the absolute difference of the subtraction, like you'd get with imabsdiff(). I'll show the later

foldera = 'C:/imagesa';
folderb = 'C:/imagesb';
folderc = 'C:/imagesc';
if ~isfolder(folderc)
    mkdir(folderc);
end
fileListA = dir(fullfile(foldera, '*.bmp'))
fileListB = dir(fullfile(folderb, '*.bmp'))
for k = 1 : length(fileListB)
    % Build file names.
    fileNameA = fullfile(foldera, fileListA(k).name);
    fileNameB = fullfile(folderb, fileListB(k).name);
    % Read them in.
    imageA = imread(fileNameA);
    imageB = imread(fileNameB);
    % Compute difference
    diffImage = imabsdiff(imageA, imageB);
    imshow(diffImage, []);
    drawnow;
    % Write out result to result folder: same base file name, different folder.
    fileNameC = fullfile(folderc, fileListA(k).name);
    imwrite(diffImage, fileNameC);
end

[Aero Descerazes]

@Image Analyst Thanks for the response. Absolute values are fine. On line 11, it gave me an error: Unrecognized field name "Name". How do I fix this? I need the exported filename same as the input images.

[Image Analyst]

Sorry. It should be lower case .name.