Intersection over Union

cal_IOU.py

def cal_IoU(img, lab, nb_class):
    for i in range(nb_class):
        mask1 = (img == (i + 1)).astype('uint8')
        mask2 = (lab == (i + 1)).astype('uint8')
        mask_and = cv2.bitwise_and(mask1, mask2)
        mask_or = cv2.bitwise_or(mask1, mask2)

        s1 = np.sum(mask_and)
        s2 = np.sum(mask_or)

        if np.sum(mask2) == 0:
            if np.sum(mask1) == 0:
                return 1.0
            else:
                return 0.0
        else:
            return s1/s2