如何分割图像并填充不同的颜色

Question

如这张图，如何用matlab代码将其分割成不同的部分，然后填充颜色呢？另外，如何在第二个代码中设置渐变色？？？

图片分割代码如下：

clc
rgb=imread('sample1.bmp');
bw=im2bw(rgb2gray(rgb),.8);
bw=medfilt2(bw);
planes=bwareaopen(bw,800);
D=mat2gray(bwdist(imcomplement(planes)));
stats=regionprops(D>.8,'Centroid');
planes_centroid=cat(1,stats.Centroid);
planes_mask=false(size(bw));     
planes_mask(sub2ind(size(bw),round(planes_centroid(:,2)),...
        round(planes_centroid(:,1))))=1;
M=imimposemin(imcomplement(D),planes_mask);
L=watershed(M);
r=L & planes;
stats=regionprops(r,'BoundingBox','Centroid')
bb=cat(1,stats.BoundingBox);
c=cat(1,stats.Centroid);
figure,imshow(planes)
hold on
for i=1:length(stats)
   rectangle('Position',bb(i,:),'EdgeColor','b')
   plot(c(i,1),c(i,2),'r*')
   text(c(i,1)-5,c(i,2)-10,num2str(i))
end
%second code
clc;clf;close all;clear all;
color=cell(4,1);
for i=1:4
input=imread(['heartspline2_4_',num2str(i)],'bmp');  
figure,imshow(input);
BW=im2bw(input,graythresh(input));
[B,L]=bwboundaries(BW,'noholes');
for k=1:length(B)
   boundary=B{k};
   ind=size(boundary(:,2));
   plot(boundary(:,2),boundary(:,1),'k','LineWidth',2);
   hold on;
   axis off;
   if (k==1)
       patch(boundary(:,2),boundary(:,1),'w');
   else
       patch(boundary(:,2),boundary(:,1),???);
   end
end
saveas(gca,['y_','heartspline2_4_',num2str(i)],'bmp')
close(gcf)
end

Answer 1

您可以使用bwlabel 为每个图像区域分配不同的索引：

img = imread('http://i.stack.imgur.com/F1Iya.jpg');  %// read image
bw = img(:,:,1) > 128;  %// convert to binary mask
lb = bwlabel(bw,4);  %// extract distinct regions

结果：

figure; imshow(lb, [], 'border', 'tight'); colormap(rand(256,3));

---

如果你想要颜色的渐变效果，你可以

[x y] = meshgrid(linspace(0,1,size(bw,2)), linspace(0,1,size(bw,1)));
rand('seed',543310);
rgb_lb = ind2rgb(lb, rand(max(lb(:)+1),3)); %// convert to RGB color image
gx = x; 
gx(lb==1)=1;  %// use the horizontal gradient
gx = gx./max(gx(:));

应用渐变：

rgb_lb = bsxfun(@times, rgb_lb, gx);

结果：