彩色图像边缘检测源代码

彩色空间梯度算子 % 算法参考A robust algorithm for text detection in color images % 输入为RGB图像IMG % 输出MAG为梯度强度，DIR为梯度方向 [M N] = size(IMG); MAG = zeros(M,N); DIR = zeros(M,N); ker1 = [-1 -2 -1;0 0 0;1 2 1]; % y direction ker2 = ker1'; % x direction % 分别计算三通道x,y方向微分 magXR = filter2(ker2,IMG(:,:,1)); magXG = filter2(ker2,IMG(:,:,2)); magXB = filter2(ker2,IMG(:,:,3)); magYR = filter2(ker1,IMG(:,:,1)); magYG = filter2(ker1,IMG(:,:,2)); magYB = filter2(ker1,IMG(:,:,3)); Mxx = magXR.*magXR+magXG.*magXG+magXB.*magXB; Mxy = magXR.*magYR+magXG.*magYG+magXB.*magYB; Myy = magYR.*magYR+magYG.*magYG+magYB.*magYB; for m=1:M for n=1:N Mc = [Mxx(m,n) Mxy(m,n);Mxy(m,n) Myy(m,n)]; % 矩阵Mc的最大特征值为梯度强度，特征向量指示梯度方向 [V,D] = eig(Mc); dx = V(1,2); dy = V(2,2); MAG(m,n) = sqrt(D(2,2)/3); DIR(m,n) = atan2(dy,dx); end; end; % 在Rafael C. Gonzalez, digital image processing,second edition 6.7.3 彩色边缘检测中也有类似叙述