Extract region-of-interest from image

roi = cv.Rect.crop(img, r)
img = cv.Rect.crop(img, r, roi)

Input

• img input image.
• r ROI rectangle [x,y,w,h].
• roi input cropped image, of size [h,w], and same type and channels as input image img.

Output

• roi output cropped image.
• img output image with updated ROI region.

In the first variant, the function gets ROI region from image, i.e: roi = img(r(2)+1:r(2)+r(4), r(1)+1:r(1)+r(3), :).

In the second variant, the function sets ROI region inside image, i.e: img(r(2)+1:r(2)+r(4), r(1)+1:r(1)+r(3), :) = roi