Template matching usink mask in opencv (emgu)

Question

I would like to find a piece of an image inside another image. However, I have some regions pixels in both images that I don't want to take into account. So I was thinking of using some type of mask with zeros or ones to indicate the good pixels.

I am using the MatchTemplate method from emgu and it does not accept a mask. Is there any other way of doing what I would like to do? Thank you!

ReferenceImage.MatchTemplate(templateImage, Emgu.CV.CvEnum.TM_TYPE.CV_TM_CCORR_NORMED);

Answer 1

I thought of a solution. Asuming that referenceImageMask and templateMask have 1s in the good pixels and 0s in the bad ones. And that referenceImage and templateImage have already been masked and have 0s in the bad pixels as well.

Then, the first result of template matching will give the not normalized cross correlation between the images.

The second template matching will give for each possible offset the number of pixels that were at the same time different from zero (unmasked) in both images.

Then, normalizing the correlation by that number should give the value I wanted. The average product for the pixels that are not masked in both images.

Image<Gray, float> imCorr = referenceImage.MatchTemplate(templateImage,      Emgu.CV.CvEnum.TM_TYPE.CV_TM_CCORR);
Image<Gray, float> imCorrMask = referenceImageMask.MatchTemplate(templateMask, Emgu.CV.CvEnum.TM_TYPE.CV_TM_CCORR);
imCorr = imCorr .Mul(imCorrMask .Pow(-1));

Answer 2

今天你可以使用这个方法：

CvInvoke.MatchTemplate(actualImage, expectedImage, result, TemplateMatchingType.CcoeffNormed, mask);