Edge detection when the boundaries are clearly marked

I have an image like this and I need to extract the regions marked by the boundaries highlighted by the color. How do I do it? This may be a simple question, but I realize no question is simple in image processing. Thanks.

[darova]

You want those boundaries to be separate?

[Kasthuri Kannan]

Yes, like the black boundary is one region, green another etc. In general, there could be as many as 9 such boundaries and I want to mark them separately. Thanks.

Answer 1

[darova]

Try this:

A = imread('test.jpeg');
subplot(1,2,1)
imshow(A)


RGB = [140 224 226];      % color you want (cyan)
% RGB = [226 129 226];      % color you want (magenta)
% RGB = [150 240 120];      % color you want (green)
% RGB = [120 120 120];      % color you want (grey)
% RGB = [120 120 190];      % color you want (violet)
% RGB = [230 170 140];      % color you want (orange)
e = 20;                   % color shift		

c1 = abs(RGB(1)-double(A(:,:,1))) < e;
c2 = abs(RGB(2)-double(A(:,:,2))) < e;
c3 = abs(RGB(3)-double(A(:,:,2))) < e;
B = (c1+c2+c3)==3;
B1 = bwareaopen(B,10);      % remove small areas
I = repmat(B1,[1 1 3]);
I = uint8(I).*A;

subplot(1,2,2)
imshow(I)

[Kasthuri Kannan]

Not really. I am looking for something like this. This is just two regions, black and green -