Q: Removing parts of the image with OpenCV I have an image and I want to simply remove(or mask) parts of it with OpenCV. this is my original image :


And I want to remove a circle on its center via this image mask : 


I use this command in my code which from the tutorials I read should work and black out a circle in the center of my original image : 
img = cv2.bitwise_not(imgOriginal,imgOriginal,mask=imgMask)

but the result I get is the image below, in fact instead of removing the masked parts, it just inverts blacks and whites:


I'll appreciate if  you can help me on finding a way to properly mask(or remove) the parts I want.
Thanks

A: Try to set pixels to the background color using a mask, like this:
img.setTo(Scalar::all(0),mask);


A: Try this:
//given source, mask and destination Mat images with same size
cv::subtract(img, mask, dst);


