How to make image intensity equalization for multiple images.
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Ivan Shorokhov
le 1 Juil 2015
Commenté : mohd akmal masud
le 14 Mar 2018
Given: I have 9 gray-scale images of the same size with slightly different intensity.
Want: I want to make uniform intensity for all the images.
Currently done: Just now I'm doing image adjustment followed be image equalization for each single image, by using code below
for x=1:9
eq_image(:,:,x)=histeq(imadjust(some_image(:,:,x)));
figure(x); imshow(eq_image(:,:,x), []);
end
Needed: How to make intensity the same for all 9 images?
[ACKNOWLEDGMENTS]
Thank you for help: Kerem tezcan, Image Analyst
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Kerem tezcan
le 1 Juil 2015
Modifié(e) : Image Analyst
le 31 Mai 2016
Hey,
When you do histogram equalization, you do that separately for each image, which is not what you want, as you have also stated.
You can normalize the images to one of them. For example choose the first image as the reference, and then calculate the mean intensities of all the images, and find the scaling between each image with the reference image by the formula: sc(n) = mean_of_ref / mean_of_ims(n). Then you can multiply all the images with the corresponding individualized scaling and you will have the same mean intensity for all the images.
Other approaches would be to normalize them according to their maximum values, or similarly to the minimum values, or to the median values.
For the scaling according to the mean of the first image, the code would look like this:
for x=1:9
mns(x) = mean2(some_image(:, :, x));
scaled_image(:, :, x) = some_image(:, :, x) * (mns(1) / mns(x));
end
You can do the histogram equalization independently of the scaling, but doing that afterwards will change the mean of any image you do it to.
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Image Analyst
le 2 Juil 2015
You can do linear scaling like kerem suggested. Another option is to use imhistmatch() to match images 2 and higher to image #1.
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mohd akmal masud
le 14 Mar 2018
Hi all
i want try open multiple images using implay. but want to change contrast first. Below is my code, but still error. anyone can help me.
P = zeros(512, 512, 313);
for K = 1 : 313
petname = sprintf('TRANSA001_CT%03d.dcm', K);
P(:,:,K) = dicomread(petname);
end
Out(:,:,K) = imadjust(P(:,:,K));
implay(Out, [-182 292]);
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