sudoku_steps.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
        o_vertices = cv2.approxPolyDP(cnt, epsilon, True)
        vertices = cv2.convexHull(o_vertices, clockwise=True)
        vertices = self.correct_vertices(vertices)

        if self.debug:
            temp = cv2.cvtColor(image.copy(), cv2.COLOR_GRAY2BGR)
            cv2.drawContours(temp, cnts, -1, (0, 255, 0), 10)
            cv2.drawContours(temp, o_vertices, -1, (255, 0, 0), 30)
            cv2.drawContours(temp, vertices, -1, (0, 0, 255), 20)
            self.save2image(temp)

        return vertices