[转]交互式选取图象感兴趣部分（矩形窗或任意区域）

Posted by trueman on 2010年07月11日 Leave a comment Go to comments

从图象选择感兴趣区域（ROI）的交互式程序，其中第一个是由矩形组成的区域，第二个是由任意曲线围成的区域，两个程序都可以处理灰度或者真彩的图象，且没有利用循环（除了输入数据点时利用ginput函数），速度应该有保证
1. 矩形区域
CODE:

hf = figure(1);
A = imread(‘board.tif’);
A = rgb2gray(A); %-此句注释后下面的处理就相当于对真彩色图像进行
imshow(A)
rect = getrect(hf);
w = round(rect(3));
h = round(rect(4));
if w >= 1 & h >= 1
    r = [rect(1),rect(1)+w,rect(1)+w,rect(1);rect(2),rect(2),rect(2)+h,rect(2)+h];
    rectangle(‘Position’,[rect(1),rect(2),w,h], ‘edgecolor’,'red’);
    figure(2);
    bw = roipoly(A,r(1,:),r(2,:));
    AA = reshape(A, [(size(A,1)*size(A,2)), size(A,3)]);
    BB = AA(bw, ;
    B = reshape(BB, [h, w, size(A,3)]);
    imshow(B);
end

用法：运行程序后，在图象任意一个地方点击鼠标左键，确定矩形左上角的坐标点，然后拖动（即之前的点击按住不放）选择感兴趣的区域，最后放手，此时矩形右下角的坐标点就确定下来了。

2. 任意曲线区域
CODE:

clear all
A = imread(‘board.tif’);
A = rgb2gray(A); %-此句注释后下面的处理就相当于对真彩色图像进行
figure(1)
imshow(A);
%[a,b] = ginput;
button = 1;
n = 0;
a = [];
b = [];
hold on;
while button == 1 % 输入数据点，以右键作结
    [xi,yi,button] = ginput(1);
    n = n + 1;
    if n > 1
        plot([xi,a(n-1,1)], [yi,b(n-1,1)], ‘-rs’,'LineWidth’,2,…
            ‘MarkerEdgeColor’,'k’,…
            ‘MarkerFaceColor’,'g’,…
            ‘MarkerSize’,10);
    else
        plot(xi, yi, ‘s’,'LineWidth’,2,…
            ‘MarkerEdgeColor’,'k’,…
            ‘MarkerFaceColor’,'g’,…
            ‘MarkerSize’,10);
    end
    a(n,1) = xi;
    b(n,1) = yi;
end
plot([xi,a(1,1)], [yi,b(1,1)], ‘-rs’,'LineWidth’,2,…
    ‘MarkerEdgeColor’,'k’,…
    ‘MarkerFaceColor’,'g’,…
    ‘MarkerSize’,10);
hold off;
if length(a) >= 3
    va = round(a);
    vb = round(b);
    x = 1:size(A,1);
    y = 1:size(A,2);
    [Y,X] = meshgrid(y,x);
    in = inpolygon(Y(:),X(:),va,vb);
    AA = reshape(A, [size(A,1)*size(A,2),size(A,3)]);
    BB = repmat(uint8(255),size(AA));
    BB(in,:) = AA(in,:);
    B = reshape(BB, [size(A,1),size(A,2),size(A,3)]);
    figure(2)
    imshow(B);
end