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cv::gpu::blur returns zero Mat when Mat is processed in place

asked 2014-02-06 05:09:41 -0500

Wolf gravatar image

updated 2014-02-06 05:10:15 -0500

With cv::blur on CPU you can process cv::Mat in place like:

// have defined and filled cv::Mat my_mat
cv::blur( my_mat, my_mat, cv::Size( 4, 4 ) );

If I try the same thing with cv::gpu::GpuMat and cv::gpu::blur like

// have defined and filled cv::gpu::GpuMat my_mat
cv::gpu::blur( my_mat, my_mat, cv::Size( 4, 4 ) );

my_mat is now just all zeros, i. e. black.

If I create an empty GpuMat header, pass it to blur and assign to Mat everything again works like CPU example:

// have defined and filled cv::gpu::GpuMat my_mat
cv::gpu::GpuMat tmp;
cv::gpu::blur( my_mat, tmp, cv::Size( 4, 4 ) );
my_mat = tmp;

I think this is a bug in cv::gpu::blur, isn't it?

I am using ubuntu 12.04 64 bit with cuda 5.5 and OpenCV 2.4.7

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GPU filters doesn't work in-place.

Vladislav Vinogradov gravatar imageVladislav Vinogradov ( 2014-02-06 12:03:02 -0500 )edit

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answered 2014-02-07 04:57:59 -0500

Wolf gravatar image

Thanks for reply. Doc of FilterEngine mentions this. Maybe the doc of blur etc. should also mention it, or the functions should assert on this. Took me quite a while to find this error when porting from CPU to GPU....

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Asked: 2014-02-06 05:09:41 -0500

Seen: 242 times

Last updated: Feb 06 '14