taking an average histogram from number of histograms

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hi, I am trying to take to the average histogram from multiple histogram , I am trying like this
img = dir('C:\Program Files\MATLAB\R2012a\bin\Patches\*.png'); % the folder in which ur images exists
for i = 1 : length(img)
filename = strcat('C:\Program Files\MATLAB\R2012a\bin\Patches\',img(i).name);
I = imread(filename);
I=I(:,:,1);
I=im2double(I);
[rows, columns, numberOfColorBands] = size(I);
if numberOfColorBands > 1
I = rgb2gray(I);
end
% [count, bin]=imhist(I);
[bin,xout]=hist(I);
for i=1:bin
bin1=sum(bin(i))./max(bin);
end
bar(xout,bin);
end
somebody please suggest how could I get the average histogram if I am having number of histograms Same discussion cuold be found here mean histogram Thanks
  2 Comments
dpb
dpb on 4 Aug 2013
Sure, just like the result of the thread you posted says--set a given range and number of bins then accumulate the counts in those bins and average.
doc histc

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Accepted Answer

dpb
dpb on 6 Aug 2013
I'm really no image processor but aiui, imhist returns 256 bins for a grayscale image so why isn't it simply the accumulation of all the counts in each bin for each image?
dirn='C:\Program Files\MATLAB\R2012a\bin\Patches';
% do the first to establish the histogram outputs
I = imread(fullfile(dirn,img(i).name));
I=I(:,:,1);
% Since you took the first plane here, the 3rd dim from size() will
% never be >1 so that's all superfluous in you code--if you do need to
% convert to grayscale, do it here though..
[cnt, bin]=imhist(I);
for i = 2 : length(img) % now accumulate rest...
filename = fullfile(dirn,img(i).name);
I = imread(filename);
I=I(:,:,1);
% ditto the above comment...
cnt=cnt+imhist(I); % the accumlator
end
cnt=cnt/length(img); % and average
stem(bin,cnt);
end
  2 Comments
Muhammad Ali Qadar
Muhammad Ali Qadar on 8 Aug 2013
Edited: Muhammad Ali Qadar on 8 Aug 2013
yes This line
cnt=cnt/length(img)
infact important to me I think i Can do it now thank you , Later I will add my Solution also

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