houghline transform, it it uses canny edge detection and hough transform. It then places a red line over any detected straight lines.

opencv下canny算法的自适应阈值的确定-adaptive threshold determination opencv under the canny algorithm

OpenCV中文参考手册.chm,本文档来源于OpenCV中文网站,常用的标准图 图像文件读入和显示 图像创建、保存和复制 Canny边缘检测 Canny边缘检测2 轮廓(contour)检测 轮廓(contour)检测2 图像旋转与缩放 读视频文件和运动问题检测 Hough线段检测 鼠标绘图 -OpenCV Chinese reference manual. Chm, this document comes from OpenCV C