The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Software » comp.soft-sys.matlab

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: sub-pixel shifting of a matrix
Replies: 14   Last Post: Feb 7, 2013 12:23 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Bruno Luong

Posts: 9,822
Registered: 7/26/08
Re: sub-pixel shifting of a matrix
Posted: Feb 6, 2013 5:49 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

"Matt J" wrote in message <keuln5$onb$>...

> Maybe, but only because there are some funny sub-optimal things happening inside conv2 implementation-wise, and because the interpolation kernel here happens to be small. There's no way the 3rd version below should be the slowest.

Of course. The reason is obvious: 2+2 = 2*2, but 10+10 << 10*10.

Bilinear interpolation - as we discussed here - requires kernel of 2. So there is no need to decompose the convolution in tensorial at the price of memory parsing twice.


Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.