MATLAB Answers


Converting Histogram of Image

Asked by mohamad mohebian on 31 Dec 2018
Latest activity Answered by Rahul punk on 15 Feb 2019
I have filtered an image and I have histogram of de-noised image. When I compared this histogram with Reference Image histogram, I noticed that there is a little different between them. How can I convert this histogram to be like Reference Image histogram?
This is hist of Reference Image.
And this is the histogram of de-noised Image:


My image is a CT and I have used a modified ICA . I got PSNR : 33 but I need more. The noisy image is based on low-dose registeration.
All I can say is that you then need to come up with a better denoising routine.
Keep in mind though that many denoising routines remove what they think are noise which does not necessarily guarantee that they will return to the original image that noise was added to.
Let's say I was looking a a photo of sand, and then I added noise to the sand. It might look nearly identical to the original sand photo. Then removing noise might make the image smoother and that might have less noise in terms of variation overall and in local neighborhoods but that won't necessarily make it more like the original image.
That up/down/up/down for the histogram does not look plausible to me for CT -- **unless* the histogram is being taken at the wrong width or with badly planned centers, or other similar mistakes are made in processing.
For example if you have uniform random over [0,2] and you round() that, then 1/4 will go to 0, 1/2 will go to 1, and 1/4 will go to 2, whereas most people would probably have guessed that 1/2 would go to 1 and 1/2 would go to 2.

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1 Answer

Answer by Rahul punk on 15 Feb 2019


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