AGAST_5_8           9 modules/features2d/perf/perf_agast.cpp enum { AGAST_5_8 = AgastFeatureDetector::AGAST_5_8, AGAST_7_12d = AgastFeatureDetector::AGAST_7_12d,
AGAST_5_8          55 modules/features2d/src/agast.cpp static void AGAST_5_8(InputArray _img, std::vector<KeyPoint>& keypoints, int threshold)