Hi Babak -

I am working with images that start at 512x512x97 voxels. Attempting to register them to a template seems to generate spurious results using my standard options, but these same images register just fine (3dwarper) when resampled to 256x256x97. So, I did the following:

Original image > resampled to 256x256x97 voxels > warped to model with 3dwarper > collected output warp field, and resampled it to 512x512x97 voxels using AFNI 3dresample > used applywarp3d to apply the 512x512x97 voxel warp field > looked at final image.

When I look at the final, output images, I found that the output image was identicle to the input image. The only thing I can figure is that 3dresample converts the warp field from INTR16 to Float 32. Does it make sense that this could be my issue? If so, is there a known way to resample a warp field?

Thanks,

Matt