[Insight-users] A problem of image border when using itk::ResampleImageFilter!

[Daniel Mace]

Jun,

I ran into the same issue with resizing images.  It's not necessarily a 
bug, but rather a rounding issue with how ITK decides to calculate 
whether the regions they are interpolating are inside/outside the 
boundary of the image.  I can't remember exactly where the rounding 
issue took place, but try adding/subtracting a small value to your scale 
change (e.g., switching from a 128*128 to a 256*256 would be a rescaling 
of 0.5, subtract off 0.000001 to make it 0.499999).

Cheers,
Dan

Jun Xiong wrote:
> Dear all,
>
>    I have a question about the image border interpolation question
> when using  ResampleImageFilter.  If i use itk::ResampleImageFilter to
> resample an image to a bigger size, the area around the image border
> (about half of the Spacing value), are NOT interpolated and as a
> result the borders are fade to the default pixel value of the
> resampling filter.  For example, if i resample a  slice(256*256) from
> the volume(size:128*128*64) in the x-z orientation(using the same
> spacing), the result image only contains 126 line effective data in
> the middle, others are default value.  It seems that, the outer half
> of the image border are not interpolated and their values were set as
> the default value directly.
>   If i use the PadImageFilter to pad the volume with one pixel, the
> result image contains 130 lines effective data. How can i get a result
>  image containing 128 lines.
>    Thank you very much!
>
>    Best regards!
>
>  Jun Xiong
> _______________________________________________
> Insight-users mailing list
> Insight-users at itk.org
> http://www.itk.org/mailman/listinfo/insight-users
>