Change of the sign of space directions and space origin due to interpolation / cropping

Support
1

Hello

Is it intended that the sign of space directions and space origin change due to interpolated cropping?

From the header files of the volumes:

Before interpolation / cropping:

type: float
dimension: 3
space: left-posterior-superior
sizes: 59 69 162
space directions: (1.26953125,0,0) (0,1.26953125,0) (0,0,0.5)
kinds: domain domain domain
endian: little
encoding: gzip
space origin: (262.79296875,250.09765625000003,54.000000000000007)

After interpolation / cropping:

type: float
dimension: 3
space: left-posterior-superior
sizes: 150 177 162
space directions: (-0.5,0,0) (0,-0.5,0) (0,0,0.5)
kinds: domain domain domain
endian: little
encoding: gzip
space origin: (336.75900268554688,337.75399780273438,53.922901153564453)

Example scene: https://gigamove.rz.rwth-aachen.de/d/id/XjfDBwn6fC5RKF

Is it possible to avoid this?

Kind regards

2

Interpolated cropping axes are not attempted to be matched to axes of the original volume, as it is not feasible in general (only when the ROI axes happen to be parallel to the original volume axes). If the image geometry is correct in physical space, it should not matter what is internal voxel coordinate system.

If you need a specific image geometry then you can create an empty reference volume with that geometry and crop&resample by using an image resample module.