Generated Segmentations do not follow image geometry

[FabianIsensee]

I would expect outputs to follow the image geometry (spacing etc) unless specified otherwise. However the segmentations are always saved in 1x1x1 spacing. This is likely due to a bug in preprocess which overwrites the original affine of the image with the resampled one in this line, so that the postprocessing function cannot resample back

https://github.com/BBillot/SynthSeg/blob/2a2aa3bbfccb83f8253a51ca8b329b9938a2646d/SynthSeg/predict_synthseg.py#L451

Later when the postprocess function tried to resample back to the original image affine, it receives the preprocessed instead of the original affine

Best, Fabian