Loading multiple images, taking mean of them and subtracting background

Hi,

I am new to the field of image analysis. my problem is that i want to load multiple images (lets say 20), take the mean of all these images to produce one image, and then subtract a background image from this mean image. Any help will be highly appreciated.

Answer 1

[Meg Noah]

change the .png for whatever file extension you are using. Are your image greyscale? If not, it might not make sense to background mean subtract different color channels of data.

myDir = '';
fileList = dir(fullfile(myDir,'*.png'));
nfiles = length(fileList);

totalValuePerImage = zeros(nfiles,1);
nPixelsPerImage = zeros(nfiles,1);

for ifile = 1:length(fileList)
    
I = imread(fullfile(myDir,fileList(ifile).name));
totalValuePerImage(ifile) = sum(I(:));
nPixelsPerImage = double(numel(I));

end

globalMean = sum(totalValuePerImage)/sum(nPixelsPerImage);

for ifile = 1:length(fileList)
    
I = imread(fullfile(myDir,fileList(ifile).name));
[~,fileLeaf,~] = fileparts(fileList(ifile).name);
I = double(I) - globalMean;
save([fileLeaf '.mat'],'I');

end