OpenCV: Denoising image / video frame

Question

I want to denoise a video using OpenCV and C++. I found on the OpenCV doc site this:

fastNlMeansDenoising(contourImage,contourImage2);

Every time a new frame is loaded, my program should denoise the current frame (contourImage) and write it to contourImage2.

But if I run the code, it returns 0 and exits. What am I doing wrong or is there an alternative way to denoise an image? (It should be fast, because I am processing a video)

Answer 1

while you are using c++ you are not providing the full argument try this that way.

cv::fastNlMeansDenoisingColored(contourImage, contourImage2, 10, 10,7, 21);

// This is Original Function to be used.
cv::fastNlMeansDenoising(src[, dst[, h[, templateWindowSize[,     searchWindowSize]]]]) → dst

Parameters:
src – Input 8-bit 1-channel, 2-channel or 3-channel image.
dst – Output image with the same size and type as src .
templateWindowSize – Size in pixels of the template patch that is used to compute weights. Should be odd. Recommended value 7 pixels.
searchWindowSize – Size in pixels of the window that is used to compute weighted average for given pixel. Should be odd. Affect performance linearly: greater.
searchWindowsSize - greater denoising time. Recommended value 21 pixels.
h – Parameter regulating filter strength. Big h value perfectly removes noise but also removes image details, smaller h value preserves details but also preserves some noise

Answer 2

I was facing this problem recently as well. I learned that you need to crop the image into patches, each of about 500x500. Then you need to denoise each patch and put it all together. This usually gets the most accurate results. Let me know if you need anything else