calculate intensity of a part of images

I have sequence of gray scale images (35000 images) with the size of 2048X700 and 12bit. I want to calculate the intensity of a part of images (e.g. from x=600px to x=800px). we know the intensity changes in each sequence in this region of images. How can I calculate the intensity of this region in each sequence and then have one image as aresult showing total intensity of this region?

I trully appreciate any help.

Answer 1

[KSSV]

imgs = dir('*.jpg') ;  % give the image extension 
N = length(imgs) ;     % Number of images 
iwant = cell(N,1) ;    % save the extracted part of image 
idx = 600:800 ;        % indices of x for which pixles to be extracted 
for i = 1:N
    img = imgs(i).name ; % name of each image 
    I = imread(img) ;    % Read the image 
    iwant{i} = I(idx,:,:) ; % save the extracted part
end

[Ham Man]

for iwant the index exceeds the array bound!

here is a sample of image and I want to save the image intensity inside the yellow region for all images.

error code: Dot indexing is not supported for variables of this type.

img = imgs(i).name ;