Qt图像处理，实现一些图像处理基本功能，包括灰度图像转换，大律法二值化，添加水印等操作。后边会陆续增加功能。使用极度类似opencv- Qt image processing, to achieve some of the basic image processing functions, including grayscale image conversion, the law of the two values, add the watermark and other operat