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

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 ]
Matt J

Posts: 4,997
Registered: 11/28/09
Re: sub-pixel shifting of a matrix
Posted: Feb 24, 2010 10:12 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

"Shalin Mehta" <shalinDOTmehtaHATESSPAM@gmail.com> wrote in message <h8svoe$rkb$1@fred.mathworks.com>...
> Just found a useful solution: Use interp2 with '*linear' option. Works factor of 2.5 faster than imtransform. Any other ideas?
=================

Yes, interp2 will still be quite slow because of all the different functionality it has to support, for example, interpolation on non-uniform grids. It is much faster to express the interpolation as a separable convolution and use
conv2().

Namely if your shift in x and y are 0<sx<1 and 0<sy<1 respectively, then you can do

Image=conv2(Image,[sx, 1-sx],'same');
Result=conv2(Image,[sy, 1-sy],'same');



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 1994-2017. All Rights Reserved.