Remove periodic noise pattern from image
显示 更早的评论
Hi,
I have a set of images taken from a video which all have a regular noise pattern which I wish to remove.
You can see this pattern clearly in pattern.jpg which I attached. This is a small segment cropped from the background of image_pattern.jpg. I used imadjust on it to make the pattern visible. If you look closely at image_pattern you can see the pattern I wish to remove without losing details/sharpness in the image.
I've also attached the log of the magnitude of the fft as it seems this may be helpful in solving this problem. I obtained this with the following code:
% Compute the 2D fft. (I is image_pattern)
frequencyImage = fftshift(fft2(I));
% Take log magnitude so we can see it better in the display.
amplitudeImage = log(abs(frequencyImage));
minValue = min(min(amplitudeImage))
maxValue = max(max(amplitudeImage))
figure(3), imshow(amplitudeImage, []);
Please let me know if there are any easy solutions to this problem, thanks.
采纳的回答
Image Analyst
2019-7-10
2 个投票
I have a demo for that, attached.
5 个评论
KAAN AYKUT KABAKÇI
2020-5-9
What is the name of this filter? Low pass, band pass or high pass?
Image Analyst
2020-5-9
That would be a band pass. For a low pass, the central portion would be erased. For a high pass the outer portion of the square would be erased. Since I only erased some internal areas, it's passing stuff in the "band" outside those erase areas.
Ali Gouhar
2020-11-7
How i can remove remove these diagonal lines from the image?
Image Analyst
2020-11-8
Ali, did you try to apply my demo to your image? If so, you forgot to attach your code.
If it's not exact enough, I'd suggest you try a modified median filter where you create a mask where the gray lines gray values are, then replace those with the median
mask = grayImage == grayLineGrayLevel
subplot(2, 2, 1);
imshow(mask);
filteredImage = medfilt2(grayImage, [7, 7]);
subplot(2, 2, 2);
imshow(filteredImage);
grayImage(mask) = filteredImage(mask);
subplot(2, 2, 3);
imshow(grayImage);
If it's still not right, start your own question.
Dominic Rockas
2021-3-9
is the fft_filter.m the same as a notch filter?
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Image Arithmetic 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
