数字图像处理中圆形感兴趣区域的提取

不免自己要用到，给保存起来！！




img = imread('r_lena.png');

grayimg = rgb2gray(img);

[imgW,imgH] = size(grayimg);

t = linspace(0, 2*pi, 50);   %# approximate circle with 50 points

r = 100;                      %半径

c = [250 250];               %圆心坐标

%get circular mask

BW = poly2mask(r*cos(t)+c(1), r*sin(t)+c(2), imgW, imgH);

rgbmask(:,:,1) = BW;

rgbmask(:,:,2) = BW;

rgbmask(:,:,3) = BW;

rgbROI = immultiply(img,rgbmask);%

grayROI = immultiply(grayimg,BW);

figure,imshow(BW);

figure,imshow(rgbROI);

figure,imshow(grayROI);

原图： mask： 灰度图mask结果： RGB图mask结果

原图：