基于GVF的snake算法模型

GRADIENT VECTOR FLOW DEMONSTRATION USING MATLAB Chenyang Xu and Jerry Prince Image Analysis and Communications Laboratory Johns Hopkins University June 17, 1997, updated on 9/9/1999 Please see contact and copyright information below. 1. Introduction and Installation Instructions ---------------------------------------------- Welcome to the Gradient Vector Flow (GVF) Active Contour Toolbox. The Matlab *.m files in this software distribution implement our GVF snake, the original (Kass, Witkin, and Terzopoulos) snake, the balloon snake, and the distance snake. These programs were designed, written and tested by Chenyang Xu and Jerry Prince. To install this software, simply unzip the file into an empty directory, making sure to ask your unzipper program to restore the directory structure of the zipped files. In this documentation, we will assume that you have unzipped the files into C:\GVF. 2. Documentation ---------------- We have included two research papers that describe GVF. You can find these in C:\GVF\papers. Brief descriptions of the software modules can be found in this file below. For more detail, you should run Matlab, add the path C:\GVF\snake, and type "help function-name". For even more help, you can read the *.m files themselves. Also, see our GVF demonstration website: http://iacl.ece.jhu.edu/projects/gvf 3. MATLAB functions ------------------- The MATLAB functions included in the distribution are found in C:\GVF\snake (assuming the distribution was unzipped into C:\GVF). They are classified and listed as follows: Image input/output rawread - Read a Portable Bitmap file, or a raw file rawwrite - Write a Portable Bitmap file, or a raw file Image Display imdisp - Display an image Active Contour snakeinit - Initialize the snake manually snakedeform - Deform snake in the given external force field snakedeform2 - Deform snake in the given external force field with pressure force snakedisp - Display a snake snakeinterp - Interpolate the snake adaptively snakeinterp1 - Interpolate the snake at a fixed resolution (better implemented than snakeinterp) Gradient Vector Flow GVF - Compute the gradient vector flow field Other dt - Simple distance transform gaussianBlur - Blurring an image using gaussian kernel gaussianMask - Generate a discrete gaussian mask To use these functions, add the path C:\GVF\snake to the Matlab path using the "path" command. Once the path is set, you can type "help snake" to list more details about the above functions. 4. Examples To see how these functions work, it is best to start by running the following example macros. To do this, in Matlab cd to the directory C:\GVF\examples. Then type one of the following commands and follow the instructions of the demo. balloon_ex.m distance_ex.m gvf_ex.m tradition_ex.m 5. Test Images -------------- ./images/U64.pgm - a U-shaped object ./images/room.pgm - a room-shaped object 6. Contact Information ---------------------- Image Analysis and Communications Lab Department of Electrical and Computer Engineering The Johns Hopkins University Baltimore, MD 21218 E-mail: chenyang@jhu.edu, prince@jhu.edu Phone: 410-516-7567 (lab) FAX: 410-516-5566 7. Copyright and Disclaimer --------------------------- Copyright (c) 1996-1997 Chenyang Xu and Jerry Prince. This software is copyrighted by Chenyang Xu and Jerry Prince. The following terms apply to all files associated with the software unless explicitly disclaimed in individual files. The authors hereby grant permission to use, copy, and distribute this software and its documentation for any purpose, provided that existing copyright notices are retained in all copies and that this notice is included verbatim in any distributions. Additionally, the authors grant permission to modify this software and its documentation for any purpose, provided that such modifications are not distributed without the explicit consent of the authors and that existing copyright notices are retained in all copies. IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. =========================================================================