image warping question interpolation of scattered data

Accelerated Computing CUDA CUDA Programming and Performance
1

Hi all,

I’m working on writing some CUDA software to remap the pixels of an image to new floating point coordinate destinations
and then interpolating between them at a grid of integer values so as to retrieve a new image which is distorted in the
way specified by the new floating point coordinate destinations. (I think this is called ‘image warping’ ?)

The problem I have is to find a good way to start, I would normally always use texture memory to interpolate in 2D, but
texture memory requires the new coordinates to be integers and this will rarely be the case…

In summary, I would like to do the same as the matlab command ‘triscatteredinterp’, but on the GPU (as the matlab command
requires about 1.5 second to complete).

Thanks for any tips,

Eluri

2

hi, for image warping (‘forward warping’) see the paper

“Fast GPU-based image warping and inpainting for frame interpolation” at
http://www.joanneum.at/index.php?id=63&no_cache=1&tx_publicationlibrary_pi1[showUid]=6013

or the slides at
http://www.nvidia.com/content/GTC-2010/pdfs/2029_GTC2010.pdf

‘reverse warping’ is simpler and usually done with texture lookups (bilinear interpolation is ‘for free’ with texture images)

best, hannes

3

Thanks for the prompt response,

I checked the information you gave me, but if I understand correctly, what that software does is to reallocate some pixels and then
‘paint’ in between the moved pixels. What I would like to do, is to reallocate all of the pixels. If I understand correctly, texture
memory interpolation doesn’t allow non-integer controle points, does it? I was hoping there would be some way around this…

Eluri