cvInitLineIterator  397 modules/imgcodecs/test/test_drawing.cpp     int count = cvInitLineIterator( &img, cvPoint(0,300), cvPoint(1000, 300), &it );
cvInitLineIterator 1088 modules/imgproc/include/opencv2/imgproc/imgproc_c.h CVAPI(int)  cvInitLineIterator( const CvArr* image, CvPoint pt1, CvPoint pt2,