Matt J
Posts:
4,992
Registered:
11/28/09


Re: subpixel shifting of a matrix
Posted:
Feb 7, 2013 11:49 AM


"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <keuml4$rtj$1@newscl01ah.mathworks.com>... > "Matt J" wrote in message <keuln5$onb$1@newscl01ah.mathworks.com>... > > > > > Maybe, but only because there are some funny suboptimal things happening inside conv2 implementationwise, 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. ============
That doesn't explain why the 3rd version was the slowest. The 3rd version uses a 10+10 tensorial operation so since 10+10 << 10*10, you would expect the 3rd version to be faster (or comparable to) the others.

