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pythonopencvregionconnected-componentsimage-thresholding

Check if pixel is inside a connected component in opencv python

I'm thresholding an image which gives me some white regions. And I have a pixel location that's located in one of these regions. I'm using opencv connectedComponentsWithStats to get the regions and then find if the pixel is in any of these regions. How can I do that?

On that note, is there a better way of finding in which thresholded region that pixel is located?

Solution 
  • numLabels, labelImage, stats, centroids = cv2.connectedComponentsWithStats(thresh, connectivity, cv2.CV_32S)

    numLabels = number of labels or regions in your thresholded image

    labelImage = matrix or image containing unique labels(1, 2, 3..) representing each region, background is represented as 0 in labelImage.

    stats = stats is a matrix of stats which contains information about the regions.

    centroids = centroid of each region.

    In your case, you can use the labelImage to find out the unique label value on the pixel coordinate to find out in which region it lies in.