[MINC-users] mincresample -like bug?

[Andrew Janke]

Do either of the files have irregular slice spacing in z ?

a
On 31/03/2015 2:30 PM, "Alex Zijdenbos" <zijdenbos at gmail.com> wrote:

> I seem to have stumbled into something unusual: a failure of mincresample.
>
> [by the way, according to the GMail spell checker, the correct spelling of
> 'mincresample' is 'creaminess'. duh.]
>
> Anyways, I have this:
>
> $ mincinfo in.mnc <https://www.dropbox.com/s/dwaz0ftbtefsfz7/in.mnc?dl=0>
> model.mnc <https://www.dropbox.com/s/ic41vwursndyonj/model.mnc?dl=0>
> file: in.mnc
> image: unsigned short 0 to 65535
> image dimensions: zspace yspace xspace
>     dimension name         length         step        start
>     --------------         ------         ----        -----
>     zspace                     96            2     -321.707
>     yspace                    134            2     -202.414
>     xspace                    134            2     -132.414
>
>
> file: model.mnc
> image: signed__ short -32768 to 32767
> image dimensions: zspace yspace xspace
>     dimension name         length         step        start
>     --------------         ------         ----        -----
>     zspace                     94            2     -319.707
>     yspace                    132            2     -200.414
>     xspace                    132            2     -130.414
>
> Now I resample in.mnc like model.mnc:
>
> $ mincresample -like model.mnc in.mnc res.mnc
> Transforming
>
> slices:..............................................................................................Done
>
> $ mincinfo res.mnc
> file: res.mnc
> image: unsigned short 0 to 65535
> image dimensions: zspace yspace xspace
>     dimension name         length         step        start
>     --------------         ------         ----        -----
>     zspace                     94            1            0
>     yspace                    132            2     -200.414
>     xspace                    132            2     -130.414
>
> Clearly, the zspace step and start of the resampled volume (yellow) don't
> look at all like those of the -like volume (green). I suspect a numerical
> precision issue causing the start/step calculation to go wrong, but I'm not
> sure.
>
> In case anybody wants to play, you can get in.mnc and model.mnc from the
> URLs in the first mincinfo call.
>
> -- A
> _______________________________________________
> MINC-users at bic.mni.mcgill.ca
> http://www.bic.mni.mcgill.ca/mailman/listinfo/minc-users
>