How to remove specific noise from image with OpenCV

Question

How I can remove this noise (rectangle 2x2px) from binary image?

What have you tried so far and what problems exactly are you having? — mag_zbc, Sep 15 '17 at 13:09

score 2 · Answer 1 · answered Sep 16 '17 at 18:44

Both @melodisease and @Jazz suggested reasonable solutions. If you plan to go for connected components and to select those larger than a specific area, don't use findContours(). Use a recent OpenCV and go for cv::connectedComponentsWithStats(). You'll find it much faster.

Full disclosure: I contributed the algorithm...

score 1 · Accepted Answer · answered Sep 15 '17 at 14:05

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Median filtering (cv::medianBlur()) / morphology operations (cv::morphologyEx(), you need opening, I believe) are often used for your case - they enable cleaning out the isolated pixels. See more in here.

answered Sep 15 '17 at 14:05

lysukhin

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score 1 · Answer 3 · answered Sep 16 '17 at 09:07

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use findContours function to remove small noisy components from your image based on area.

answered Sep 16 '17 at 09:07

Jazz

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How to remove specific noise from image with OpenCV

3 Answers3