I was wondering if this code could be vectorized, and if so, can it be done without conditionals or loops? It would be great if the vectorized form could be written out so that I could run and follow

height = 666;

tri = ones(height);
start= length(tri) + 1;
for column = 1:length(tri)
    tri(start:end, column)=0;
    if column < (length(tri)/2)
*** no more help needed 

Answer 1

[Bjorn Gustavsson]

Sure, you could generate 2 coordinate matrices x and y with meshgrid:

nPix = 66;
[x,y] = meshgrid(1:nPix);

Then you'll have two boundary-lines separating the high and low-level images, in order to set those you can do things like this:

Im = (1 - double(y<2*x))/2; % this is just for one of the boundaries but you can add that condition

And then add the random noise:

Im = Im + 0.5*rand(size(Im));

HTH

[Emily Iniguez]

Thank you!

Answer 2

[darova]

• use impoly to create triangle region

tri = ones(height);
imshow(tri)
p = impoly(gca,[0 1; 1/2 0; 1 1]*height);
tri1 = p.createMask;
imshow(tri1)

• second part of the code can be simplified

xmas = zeros(height);
xmas = abs(tri1 - noi);