第7章 边沿检测与提取，轮廓跟踪 我们在第三章介绍平滑与锐化时引入了模板操作，今天还要用到它。-Chapter 7 of the edge detection and extraction, contour tracing, we introduce in Chapter III, when the introduction of smoothing and sharpening the template operation, would also like to use it today.