Fill the holes in emgu cv

Question

How can I fill the holes in binary image in emgu cv? In Aforge.net it's easy, use Fillholes class.

Answer 1

Thought the question is a little bit old, I'd like to contribute an alternative solution to the problem.

You can obtain the same result as Chris' without memory problem if you use the following:

private Image<Gray,byte> FillHoles(Image<Gray,byte> image)
    {
        var resultImage = image.CopyBlank();
        Gray gray = new Gray(255);
        using (var mem = new MemStorage())
        {
            for (var contour = image.FindContours(
                CHAIN_APPROX_METHOD.CV_CHAIN_APPROX_SIMPLE, 
                RETR_TYPE.CV_RETR_CCOMP, 
                mem); contour!= null; contour = contour.HNext)
            {
                resultImage.Draw(contour, gray, -1);
            }
        }

        return resultImage;
    }

The good thing about the method above is that you can selectively fill holes that meets your criteria. For example, you may want to fill holes whose pixel count (count of black pixels inside the blob) is below 50, etc.

private Image<Gray,byte> FillHoles(Image<Gray,byte> image, int minArea, int maxArea)
    {
        var resultImage = image.CopyBlank();
        Gray gray = new Gray(255);

        using (var mem = new MemStorage())
        {
            for (var contour = image.FindContours(
                CHAIN_APPROX_METHOD.CV_CHAIN_APPROX_SIMPLE, 
                RETR_TYPE.CV_RETR_CCOMP, 
                mem); contour!= null; contour = contour.HNext)
            {
                if ( (contour.Area < maxArea) && (contour.Area > minArea) )
                    resultImage.Draw(contour, gray, -1);
            }
        }

        return resultImage;
    }