aggregate-images: Unexpected results #691
Description
When processing images with only natural numbers in mode/majority mode, aggregate-images generates images containing non-natural numbers. Expected result is for all voxel values in the output to be members of the set of voxel values in the input images. Sample session (where the result agg.nii.gz is expected to be identical to the input seg95.nii.gz):
$ info seg95.nii.gz | grep type
Voxel type is unsigned char
$ calculate-element-wise seg95.nii.gz
Mean = 9.9747
Standard deviation = 20.819
Extrema = [0, 95]
Range = 95
$ aggregate-images mode seg95.nii.gz seg95.nii.gz seg95.nii.gz -output agg.nii.gz
$ info agg.nii.gz | grep type
Voxel type is float
$ calculate-element-wise agg.nii.gz
Mean = 10.542
Standard deviation = 20.553
Extrema = [0.74219, 94.258]
Range = 93.516
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