imagethreshold.rar_MATLAB的threshold_OTSU_threshold matlab_阈值分割 M

function [out,n,cts] = colorthreshold(im,thresholdmethod) %COLORTHRESHOLD thresholds color images. Please read Dr. Yingzi (Eliza) % Du's paper in Optical Engineering and Dr.Du's Dissertation, % Y.Du; C.-I Chang; and P.D. Thouin, "An Unsupervised Approach to Color Video Thresholding", % Optical Engineering, Vol. 43, No. 2, 282-289, (2004). % Y.Du, Text Detection and Restoration of Color Video Image, Univ. of % Maryland, Baltimore County, (2003). % Y.Du, Matlab code for color image thresholding, % http://www.gl.umbc.edu/~ydu1 % % COLORTHRESHOLD takes a color image IM as its input, and lets the user selects the threholding % method. The function returns a color thresholded image OUT of the same size as IM, % total number of colors in N, and the center of colors in CTS. % % COLORTHRESHOLD supports seven different gray-scale thresholding methods: % Summary of different gray-scale thresholding methods you can select % ----------------------------------------------------------------------- % OTSU using the OTSU's method % LE using Local Entropy Method % JE using Joint Entropy Method % GE using Globle Entropy Method % LRE using Local Relative Entropy Method % JRE using Joint Relative Entropy Method % GRE using Globle Relative Entropy Method % % Example % ------- % Threshold the color image laden.jpg using the OTSU and JRE method: % % im = imread('laden.jpg'); % out1 = colorthreshold(im,'otsu'); % out2 = colorthreshold(im,'JRE'); % imshow(out1); % figure, imshow(out2) % % The following programs must be downloaded and put in the same directory % in order to use this function: % otsu.m the function to threshold gray-scale image using Otsu's method % hist2D.m the function to generate the 2D histogram based on the % cooccurence matrics % entropythreshold2D.m the function to threshold gray-scale image using % local/joint/global entropy methods % rltentrpthreshold2D.m the function to threshold gray-scale image using % local/joint/global relative entropy methods % cluster3D.m the function to recluster the color centers % % Copyright Yingzi (Eliza) Du % Date: Mar. 8, 2004 im=double(im); co=size(im,1); ro=size(im,2); im1=im(:,:,1); im2=im(:,:,2); im3=im(:,:,3); tmethod = 0; if strcmpi(thresholdmethod,'otsu') tmethod = 1; rk=otsu(im1); gk=otsu(im2); bk=otsu(im3); end; if strcmpi(thresholdmethod,'le') | strcmpi(thresholdmethod,'Je') | strcmpi(thresholdmethod,'Ge') tmethod = 2; [KL1,KJ1,KG1] = entropythreshold2D(im1); [KL2,KJ2,KG2] = entropythreshold2D(im2); [KL3,KJ3,KG3] = entropythreshold2D(im3); if strcmpi(thresholdmethod,'le') rk = KL1; gk = KL2; bk = KL3; end; if strcmpi(thresholdmethod,'je') rk = KJ1; gk = KJ2; bk = KJ3; end; if strcmpi(thresholdmethod,'ge') rk = KG1; gk = KG2; bk = KG3; end; end; if strcmpi(thresholdmethod,'lre') | strcmpi(thresholdmethod,'jre') | strcmpi(thresholdmethod,'gre') tmethod = 3; [KL1,KJ1,KG1]=rltentrpthreshold2D(im1); [KL2,KJ2,KG2]=rltentrpthreshold2D(im2); [KL3,KJ3,KG3]=rltentrpthreshold2D(im3); if strcmpi(thresholdmethod,'lre') rk = KL1; gk = KL2; bk = KL3; end; if strcmpi(thresholdmethod,'jre') rk = KJ1; gk = KJ2; bk = KJ3; end; if strcmpi(thresholdmethod,'gre') rk = KG1; gk = KG2; bk = KG3; end; end; if tmethod == 0 %input wrong methods error('Unrecognized thresholding method'); end; imt = zeros(co,ro,3); %The pre-thresholded thresholded image imt(:,:,1)=(im2>rk); imt(:,:,2)=(im2>gk); imt(:,:,3)=(im3>bk); [out, n, cts] = cluster3D(im,imt);