MATLAB角点检测（Susan）

README ============================================================ Name: edgetools (edgemap.m + edgedir.m) Version: 1.0 Revision: 005 Release date: 2007-03-22 Author: Nicola Asuni Copyright (c) 2006: Tecnick.com S.r.l. Via Ugo Foscolo n.19 09045 Quartu Sant'Elena (CA) ITALY http://www.tecnick.com Software License: GNU GENERAL PUBLIC LICENSE v.2 http://www.gnu.org/copyleft/gpl.html Descriptions: edgemap.m % DESCRIPTION % -------------------- % This function detects edges, which are those places in an image that % correspond to object boundaries. To find edges, this function looks % for places in the image where the intensity changes rapidly, using % an improved SUSAN technique. % % This algorithm is based on the technique described on: % S.M. Smith, J.M. Brady, "SUSAN - a new approach to low level image % processing", Int Journal of Computer Vision, 23(1):45-78, May 1997. % This technicque is subject to a patent: % S.M. Smith, "Method for digitally processing images to determine the % position of edges and/or corners therein for guidance of unmanned % vehicle. UK Patent 2272285. Proprietor: Secretary of State for % Defence, UK. 15 January 1997. % USAGE % -------------------- % [EDG] = edgemap(IM) % [EDG] = edgemap(IM, TR) % [EDG] = edgemap(IM, TR, KR) % [EDG] = edgemap(IM, TR, KR, NR) % [EDG] = edgemap(IM, TR, KR, NR, OP) % INPUT % -------------------- % IM : source image (RGB or grayscale) % TR : Brightness Threshold (default = 20) % KR : USAN Kernel Radius (nucleus excluded) (default = 3) % NR : EDG matrix will be normalized to this range of integers % (default = 0 = not normalize) % OP : if true removes from USAN the pixels that are not % directly connected with the nucleus (default = false). % IMPORTANT: This optimization is very slow, so use it carefully % only for small images and when it's really needed. % OUTPUT % -------------------- % EDG : edge strength image % Examples % -------------------- % Please check the edgexample.m and edgexample2.m files on how to use % this function. % NOTES % -------------------- % This implementation is not intended to be used in a production % environment. The main purpose of this script is to clearly show how % this technique works. Better performaces could be obtained using a % compiled version or rewriting this technique using a low-level % programming language. % --------------------------------------------------------------------- edgedir.m % DESCRIPTION % -------------------- % This function detects the angles of the tangents to image edges. % Angles are counted counter-clockwise starting from horizontal. % The edges are those places in an image that correspond to object % boundaries. % To find the angles of edges, this function uses a modified SUSAN % technique. % % This algorithm is based on the technique described on: % S.M. Smith, J.M. Brady, "SUSAN - a new approach to low level image % processing", Int Journal of Computer Vision, 23(1):45-78, May 1997. % This technicque is subject to a patent: % S.M. Smith, "Method for digitally processing images to determine the % position of edges and/or corners therein for guidance of unmanned % vehicle. UK Patent 2272285. Proprietor: Secretary of State for % Defence, UK. 15 January 1997. % USAGE % -------------------- % [ANG] = edgedir(EDG) % [ANG] = edgedir(EDG, KR) % [ANG] = edgedir(EDG, KR, OP) % INPUT % -------------------- % EDG : edge strength image % KR : USAN Kernel Radius (nucleus excluded) (default = 3) % OP : if true removes from USAN the pixels that are not % directly connected with the nucleus (default = false). % IMPORTANT: This optimization is very slow, so use it carefully % only for small images and when it's really needed. % OUTPUT % -------------------- % ANG : angles of the tangents to image edges (edge orientation) in % radiants ]0,pi]. Angles are counted counter-clockwise starting % from horizontal. % Examples % -------------------- % Please check the edgexample.m and edgexample2.m files on how to use % this function (uncomment the last line of these files to calculate % and print the edge orientation matrix). % NOTES % -------------------- % This implementation is not intended to be used in a production % environment. The main purpose of this script is to clearly show how % this technique works. Better performaces could be obtained using a % compiled version or rewriting this technique using a low-level % programming language. % --------------------------------------------------------------------- Example: Check the edgexample.m and edgexample2.m scripts for usage example. ============================================================