说明：  用Prewitt算子检测图像的边缘，用不同σ值的LoG算子检测图像的边缘，用Canny算子检测图像的边缘，图像的阈值分割，用水线阈值法分割图像
(Prewitt operator with the image edge detection, using a different σ value Log Operators image edge detection using Canny operator image edge detection, image thresholding, water line thresholding segmentation image)