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Topic: LUT/vectorize this for-loop
Replies: 1   Last Post: Feb 12, 2013 11:14 AM

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 Wael Posts: 85 Registered: 7/21/09
LUT/vectorize this for-loop
Posted: Feb 12, 2013 11:07 AM

Hello,

I have been dabbling trying to make a look-up table mapping for this tedious for-loop but I wasn't successful. Here is the code and explanation of what I am trying to do:

for kk=1:size(aa,1)
imageModified(aa(kk,1),aa(kk,2))=img(aa(kk,3),aa(kk,4));
end

My 'kk' is in order of millions for this loop is somehow time consuming.

Basically, I have a matrix called 'aa'.

'aa' is some Nx4 matrix where each row has mapping values.

What I want to do is going through row by row of matrix 'aa' and map image value 'img' to its corresponding place in image 'imageModified'.

For example,

Let's say aa=[ 50 40 60 70 ;
2 56 28 10 ;
.... ]

So what I want to do is: map img(50,40) value to location imgModified(60,70). Map map img(2,56) value to location imgModified(28,10). And do that for aa N rows.