
Re: subpixel shifting of a matrix
Posted:
Feb 6, 2013 5:49 PM


"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.
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.
Bruno

