ginput

Hi all,

I have 160 slices(408*544*160) with a 3d patch on it. I need to find one point on each slice and take in return a 3d matrix of patch: it is my idea but it seems has a fundamental misunderstanding.

d=zeros(408,544,160);
for i=1:160
figure,imshow(image(:,:,i)),[]);
[a,b]=ginput(1);
z=image(a,b,i);
d(a,b,i)=z;
end

how can i fix it?

I was wondering if I can select random point in each slice?when I use ginput, there is noting to stop it from receiving points. How can take it in return as 3d matrix?

Answer 1

[Sean de Wolski]

d=zeros(408,544,160);
image = rand(size(d));
for i=1:160
  figure,imshow(image(:,:,i),[]);
  [a,b]=ginput(1);
  a = round(a);
  b = round(b);
  z=image(a,b,i);d(a,b,i)=z;
end

You have to round the points returned from ginput to account for floating points. I would also recommend against opening a new figure on each iteration.

[bahar cham]

Thanks. It works. But, can you say what do you mean:"recommend against opening a new figure on each iteration"and what is your idea?

[Sean de Wolski]

well if you run the above code, you'll end up with 160 open figures. Which is a lot of clutter, not to mention used memory. I would either close the figure after ginput() or overwrite the image with each call to imshow().