How to remove gaussian noise?

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Abirami
Abirami 2014-11-1
评论： Image Analyst 2020-12-28
Hello, I'm working on image encryption. I need to see how well my encryption is so i thght of adding noise and testing it.I added gaussian noise with the following code.My problem is i dont know how to remove it before applying decryption algorithm.i get decimal values, I want to get whole numbers in the resulting matrix.
I=imread('leena.bmp');
M =0;
V=0.01;
imshow(I);
title('Original Image');
J = imnoise(I,'gaussian',M,V);
figure,imshow(J);
title('Gaussian Noise');
i'm planning to add other noises as well like poisson noise, speckle noise and salt and pepper noise. Is there any possibility that a code exists for removing all these noises separately? please help..thanks in advance
  2 个评论
Image Analyst
Image Analyst 2020-8-13
Did you look up imnoise() in the help? M is the mean and V is the variance. From the help:
J = imnoise(I,'gaussian',m,var_gauss) adds Gaussian white noise with mean m and variance var_gauss.

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采纳的回答

Image Analyst
Image Analyst 2014-11-1
For Gaussian noise, the maximum likelihood de-noised answer would just be a local mean, which you can do with conv2():
denoisedImage = conv2(double(noisyImage), ones(3)/9, 'same');
If you want to do Salt and Pepper noise, then see my attached demos where I use a modified median filter.
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Image Analyst
Image Analyst 2020-8-13
If you check the documentation you'll see that it's the window size of the window that scans across the image.
agung pratama
agung pratama 2020-8-13
Thanks Image Analyst, have a good day

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更多回答（1 个）

lakpa tamang
lakpa tamang 2019-12-15
Image Analyst.. can you explain how does the denoising works actually.. mathamatically?
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RAJSHREE SRIVASTAVA
RAJSHREE SRIVASTAVA 2020-12-28
Image analyst , I am trying to excute the last file of
But I am getting error : salt_and_pepper_noise_removal_grayscale
Undefined function or variable 'salt_and_pepper_noise_removal_grayscale'.
Please do help
Image Analyst
Image Analyst 2020-12-28
How are you trying to run it? Is it open in the editor window? Did you click the green run triangle? Then it will run. I just ran it again to make sure everything works fine, and it does.

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