if y1 != 0 and y2 != 0:
    break
for i in range(2, w):
    if horizontal[i] > void_th and x1 == 0:
        x1 = i
if horizontal_rev[i] > void_th and x2 == 0:
    x2 = i
if x1 != 0 and x2 != 0:
    break
desired_result = img[y1:h - y2, x1:w - x2]
cv2.imshow('Crop', desired_result)
Crop image with corrected distortion in OpenCV (Python)