Avoiding FOR loops to select a region in matrix and minimise computation time
1 回表示 (過去 30 日間)
古いコメントを表示
Hello,
I am trying to write a cross-correlation script where I need to slide my template across all rows and columns in the subject. Currently I am using nested FOR loops to select rows and columns every time I do a search. However, the computational time is quite high and I wanted to minimise it by avoiding FOR loops by any mean possible. For obvious reasons, I cannot publish my code yet. However, I can provide a pseudo code:
T = imread('template.png')
S = imread('subject.png')
[rowT, columnT] = size(T);
[rowS,columnS] = size(S);
coeff = zeros(size(S));
for ii=0:(rowS-rowT)
for jj = 0:(columnS - columnT)
ss = S(ii+1:rowT+ii,jj+1:columnT+jj);
.
.
.
coeff(ii+1,jj+1) = (lambdaRo^2)*(lambdaGamma^2);
end
end
Is there any way to avoid using for loops to select region of my subject image and speed the calculation time up? From my limited experience in Mathematics and MATLAB (compared to what the community users' experience is) I don't see how it is possible. Please help me out!!
Kind Regards,
6 件のコメント
Image Analyst
2012 年 10 月 18 日
Again, why not use xcorr2()? Though, I admit I didn't study your code. Do you have some kind of unusual custom correlation that doesn't do the same thing as the built-in function?
回答 (1 件)
参考
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!