MATLAB: Standard Deviation Between images

for loopimage processingstatistics

Hi there,I currently have set of images which I get from taking the average from a group of smaller images, I am just wondering if it is possible if I could get an array of the std deviation between the images from n2 to n1? Everytime I try I end up taking just the Overall Standard Deviation from the image
if true
   for n=n1:n2
  stem='E:\29th April New\NEW Gain=99_No Delay_ Gate=0.02_0';
  r=n-1;
  r=int2str(r);
  combinedStr=strcat(stem,r);
  Images=99;
  t=10;
AvgImg =(zeros(1024,1280)); 
    for i=t:Images;
        B=readimx(fullfile(combinedStr,['B000',int2str(i),'.im7']));
        C=B.Frames{1}.Components{1};
        V = C.Planes;
        Img = V{1,1};
        J = imrotate(Img,-90);
        I2 =(flip(J,2));
        FUNC=@(x)max(x(:));
        I3=medfilt2(I2,[1 1]);
        AvgImg = AvgImg +double(I3);
    end
    figure(n-1)
    AverageImg = AvgImg/(Images-t);
   AverageImgB=90;
    AverageImgLII=uint16(AverageImg-AverageImgB);
    K=imagesc(flipud(AverageImgLII));
    set(gca,'YDir','normal');
  end

Best Answer

Store your images in a 3D matrix and calculate all your stats in one go using mean, std, etc. on the 3rd dimensions:
numimages = 99
stem = 'E:\29th April New\NEW Gain=99_No Delay_ Gate=0.02_0';
for gating = n1:n2
  stemgating = sprintf('%s%d', stem, gating-1);
  LIIimages = cell(1, numimages);  %storing in a cell array, to be converted to 3D matrix later on
  for imgindex = 1:numimages
     imxstruct = readimx(fullfile(stemgating, sprintf('B%05d.im7', imgindex)));
     img = imxstruct.Frames{1}.Componenets{1}.Planes{1};
     LIIimages{imgindex}= imrotate(img, -90);
  end
  %convert cell array to 3d matrix
  LIIimages = cat(3, LIIimages{:});
  %calculate stats:
  meanimg = mean(LIIimages, 3);
  stdimg = std(LIIimages, 0, 3);
  %... do more stuff
end
Note that I'm storing the images temporarily into a cell array. This avoids having to hardcode the size of the images (the alternative is to predeclare the 3D array with zeros(1024, 1280, numimages))
Also note, that I've fixed the problem with you not being able to create properly the name of the first 9 buffer images by using sprintf with a format string that says to prepend the number with enough zeros to have 5 digit (the '%05d')
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