简单的图形图像处理源程序，做为入门极为合适。包括图像的半影调和抖动技术 及边沿检测与提取轮廓跟踪等技术。清华大学吕凤军-Simple graphical image processing source code, as entry is very appropriate. To reconcile the image of the penumbra, including Jitter and contour tracing edge detection and extraction techni