Opencv Python Crop Image Using Numpy Array

Question

I am using OpenCV 3.1.0-dev and python 2.7.

I am trying to crop out the black exterior of an image I have stitched. The struggle is that there are other pixels in t

Answer 1

Once you have the contours, you can do a list of the x and the y of them and then find the maximum and minimum:

x, y = [], []

for contour_line in contours:
    for contour in contour_line:
        x.append(contour[0][0])
        y.append(contour[0][1])

x1, x2, y1, y2 = min(x), max(x), min(y), max(y)

cropped = img[y1:y2, x1:x2]

The (x1, y1) would be the top left corner and the (x2, y2) the bottom right.

Hope this helped!