How to get x,y coordinates of each pixels in a connected component ??

Dear all,

    I =  imread('image.jpg');

    I2 = im2bw(I) ;

    st = regionprops( I2, 'PixelIdxList', 'PixelList');

We can get pixelId list and pixels of connected components as above. But I need to get the x,y coordinates of each pixels. Anybody can help me?

Thank you..

Answer 1

[Andrei Bobrov]

st = regionprops( I2,  'PixelList');
xy=cat(1,st.PixelList)
xy(:,2) = abs(xy(:,2) - size(I2,1)) + 1
plot(xy(:,1),xy(:,2),'g*')

Answer 2

[Sean de Wolski]

[y x] = find(I2)

Answer 3

[Paulo Silva]

bw = imread('text.png');
L = bwlabel(bw);
s  = regionprops(L, 'centroid');
XY=[s.Centroid];
ax=axes
hold on
imshow('text.png','Parent',ax)
plot(ax,XY(1:2:end),XY(2:2:end),'*')

[nayomi ranamuka]

This is useful to get coordinates from user interface.But I need to get coordinates from pixel Ids. But I don't know that it's possible or not.

Thank you

Answer 4

[Sergio Arango]

[x,y]=size(I2);
[~,y2]=size(st.PixelIdxList);
for i=1:y2
    locs(i,1)=rem(st.PixelIdxList{1,i}(1),x);
    locs(i,2)=fix(st.PixelIdxList{1,i}(1)/y)+1;
end

This code gives you the locations of the first pixel in each region. I don't know if this one's helpful, but I hope so :)

[Walter Roberson]

That looks to me as if it could be written in terms of ind2sub()