sudoku.py 文件源码

def extract_corners(self, image):
        """
        Find the 4 corners of a binary image
        :param image: binary image
        :return: 4 main vertices or None
        """
        cnts, _ = cv2.findContours(image.copy(),
                                   cv2.RETR_EXTERNAL,
                                   cv2.CHAIN_APPROX_SIMPLE)[-2:]
        cnt = cnts[0]
        _, _, h, w = cv2.boundingRect(cnt)
        epsilon = min(h, w) * 0.5
        vertices = cv2.approxPolyDP(cnt, epsilon, True)
        vertices = cv2.convexHull(vertices, clockwise=True)
        vertices = self.correct_vertices(vertices)

        return vertices