[MINC-users] mincresample modifying data

[Vladimir S. FONOV]

Hello,

mincresample -nearest produces expected results, so probably there is
something "interesting" in linear interpolation code.

On Wed, Aug 14, 2013 at 3:18 PM, Andrew Wood <andrew at biospective.com> wrote:
> Hi all,
>
> I've been experiencing some behaviour coming out of mincresample that I
> can't explain. I've been trolling through the source code and wondering
> about a number of things that might contribute to my problem, but I've
> boiled it down to one simple example:
>
> Here is a volume in.mnc (a signed float volume):
> https://www.dropbox.com/s/cyfujyenc4j7h8b/in.mnc
>
> $ mincresample in.mnc rsl.mnc
>
> Then compare with mincstats:
>
> $ mincstats -min in.mnc
> Min:               0
> $ mincstats -min rsl.mnc
> Min:               -5.345658291e-11
>
> And here it is from the header:
>
> $ mincinfo -attvalue image:valid_range in.mnc
> 0 26989.404296875
> $ mincinfo -attvalue image:valid_range rsl.mnc
> -5.3456582910227368188e-11 26989.404296875
>
>
> I also tried with -keep_real_range, which I gather doesn't make sense on
> float data anyway, but definitely further mucks things up:
>
> $ mincresample in.mnc rsl_krr.mnc
> $ mincstats -min rsl_krr.mnc
> *** mincstats - reported min (-5.34566e-11) doesn't equal header (0)
> *** mincstats - reported max (6.90125e-11) doesn't equal header (1)
> Min:               -5.345658291e-11
>
> Does anyone have any insight into what might be happening?
>
> Thanks,
> Andrew
> _______________________________________________
> MINC-users at bic.mni.mcgill.ca
> http://www.bic.mni.mcgill.ca/mailman/listinfo/minc-users



-- 
Best regards,

 Vladimir S. Fonov ~ vladimir <dot> fonov <at> gmail <dot> com