Tracing in Matlab

Just found this bit of code and I had a few questions:

I = imread('image.jpg');
BW = im2bw(I, graythresh(I));
[B,L] = bwboundaries(BW,'noholes');
imshow(label2rgb(L, @jet, [.5 .5 .5]))
hold on
for k = 1:length(B)
    boundary = B{k};
    plot(boundary(:,2), boundary(:,5), 'w', 'LineWidth', 2)
end

Is it possible to not have it fill in holes with random colours?

Is it possible to animate the tracing process so that I can watch it being traced?

How would I go about rendering images so that they would fit in a specific size? (1980 x 1080 image to fit inside a 800 x 600 box).

I'll be putting all of this in a clean GUI so that it can browse and trace images straight from the GUI!

All help appreciated thanks!

Answer 1

[Walter Roberson]

The colors are controlled by the function being passed, @jet

[Aaron]

How would I go about changing it? (To white for example and the tracing to be black)