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Subject: Re: conv2 in R2008b very slow
Date: Thu, 18 Dec 2008 18:21:03 +0000 (UTC)
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"Andreas Sprenger" <sprenger_a@yahoo.de> wrote in message <gie3tb$qen$1@fred.mathworks.com>...
> I just realized that conv2 is very slow in 2008b. I created a 2D filter by
> 
> GaussWidth = [23, 180];
> F = customgauss([GaussWidth(2), GaussWidth(2)], GaussWidth(1), GaussWidth(1), 0, 0, 1, [0 0]);
> % custumgauss -> see FileExchange
> 
> % Array of zeros
> G1 = zeros(600, 1000);
> 
> % Set one single point 
> G1(300, 400) = 1.5;
> 
> % in R2008a: 
> tic; G2 = conv2(G1, F, 'same'); toc
> >> Elapsed time is 0.014846 seconds.
> 
> % in R2008b:
> tic; G2 = conv2(G1, F, 'same'); toc
> >> Elapsed time is 17.831022 seconds.
> 
> Same machine, no background activity, reproducable. Why?
> 
> Andreas



Can you give the dimensions of F? I don't want to have to download customgauss off the FEX to make this test.