[Python] How to use OpenCV cornerSubPix() in Python?

I'm trying to get and paint corner points in an image. Now, I have a list of tuples with the following format: (row,column,scale) (scale is because I'm using a Gaussian Pyramid), obtained from harrisCornerDetector and nonMaximumSupression process manually. This list is featuresy1.

My code is the following:

r,g,b=cv2.split(image)
criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)
cv2.cornerSubPix( r, featuresy1, (5,5), (-1,1), criteria )


Where image is an image in grayscale with three identical shapes. As you can see, I'm giving to cornerSubPix as second parameter a structure like this: [(x1,y1,scale1),(x2,y2,scale2),...,(xn,yn,scalen)].

This is throwing the following error:

cv2.cornerSubPix( r, featuresy1, (5,5), (-1,1), criteria )
TypeError: corners is not a numpy array, neither a scalar


For this reason I wonder what type, format or structure should have featuresy1 to do cornerSubPix() working. Is this the only thing I'm doing wrong? There isn't much documentation about this.

Thanks!

Continue reading...