获取图像上的曲线数据，读入一幅图片并选取所需的数据点加以保存处理。用法：使用鼠标左键取点，右键结束取点并保存数据-Get the curve on the image data, read and select a picture to save the data points needed to deal with. Usage: Use the left mouse button to take point, right end of the access point and save the data