Is the a max size for conv2

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Thomas Hoyle 2017-2-27

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https://ww2.mathworks.cn/matlabcentral/answers/327157-is-the-a-max-size-for-conv2

评论： Thomas Hoyle 2017-2-28

Hi I'm having a problem with conv2 every time I try to use it matlab gets stuck in "busy" and I cant do anything. If I try to pause the script it just gets stuck in "pausing". I am using 2D matrices with sizes 3909x4000 double. Has anyone ecountered this problem or has a solution any help would be appreciated.

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Jan 2017-2-27

Please post the relevant part of the code. One input is [3909x4000] and the other?

Thomas Hoyle 2017-2-28

在 MATLAB Online 中打开

This is the code I am using

PSF = deconvreg(output,input);
Pnz = deconvreg(output, PSF);
acc = conv2(Pnz, PSF);

The input, ouput, PSF and Pnz are all 3909x4000

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Answer 1

Guillaume 2017-2-27

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/327157-is-the-a-max-size-for-conv2#answer_256508

As discussed by Yair, matlab's convolution seem to be using the standard sliding window algorithm, which if you're using on two 3909x4000 is going to result in a great deal of operations (~2e14 sliding positions). As also discussed in that post, you can use the fact that the fourier transform of the convolution is the product of the Fourier Transforms of the inputs.

There's an implementation of it on the FileExchange .