make_phantom - Signed byte volumes created with wrong voxel range

[bbbxyz]

$ make_phantom -signed -byte -clobber test.mnc && mincheader test.mnc 
hdf5 test {
dimensions:
        xspace = 128 ;
        yspace = 128 ;
        zspace = 128 ;
variables:
        byte image(xspace, yspace, zspace) ;
                image:version = "MINC Version    1.0" ;
                image:vartype = "group________" ;
                image:valid_range = 0., 255. ;
                image:varid = "MINC standard variable" ;
                image:complete = "true_" ;
                image:dimorder = "xspace,yspace,zspace" ;
                image:signtype = "signed__" ;
[...]

Note the valid_range being 0 to 255 which doesn't work for signed bytes. The range should be -128 to 127 right?
Using mincstats on the same volume gives me :

mincstats test.mnc
*** mincstats - reported max (0) doesn't equal header (1)
File:              test.mnc
Mask file:         (null)
Total voxels:      2097152
# voxels:          2076816
% of total:        99.03030396
Volume (mm3):      16614528
Min:               0
Max:               0
Sum:               0
Sum^2:             0
Mean:              0
Variance:          0
Stddev:            0
CoM_voxel(x,y,z):  0 0 0
CoM_real(x,y,z):   0 0 0

Histogram:         (null)
Total voxels:      2097152
# voxels:          2076816
% of total:        99.03030396
Median:            0.0005000000119
Majority:          0.0002500000119
BiModalT:          0.5002499819
PctT [  0%]:       0.0002500000119
Entropy :          0

[gdevenyi]

There are indeed a few places where the value range is hard-coded and isn't adapted properly for changing the output type:
https://github.com/BIC-MNI/mni_autoreg/blob/develop/make_phantom/make_phantom.c#L278-L281

It looks like you could fix this with:
-voxel_range -128 127

I'll need to dig into http://www.bic.mni.mcgill.ca/~david/volume_io/volume_io.html to figure out how to programmaticly set the voxel range properly given the default voxel range for a given voxel type.

> make_phantom -voxel_range -128 127 -signed -byte -clobber test.mnc && mincheader test.mnc 
hdf5 test {
dimensions:
        xspace = 128 ;
        yspace = 128 ;
        zspace = 128 ;
variables:
        byte image(xspace, yspace, zspace) ;
                image:version = "MINC Version    1.0" ;
                image:vartype = "group________" ;
                image:valid_range = -128., 127. ;
                image:varid = "MINC standard variable" ;
                image:complete = "true_" ;
                image:dimorder = "xspace,yspace,zspace" ;
                image:signtype = "signed__" ;
        double image-min ;
                image-min:version = "MINC Version    1.0" ;
                image-min:vartype = "var_attribute" ;
                image-min:varid = "MINC standard variable" ;
        double image-max ;
                image-max:version = "MINC Version    1.0" ;
                image-max:vartype = "var_attribute" ;
                image-max:varid = "MINC standard variable" ;
        double xspace ;
                xspace:version = "MINC Version    1.0" ;
                xspace:vartype = "dimension____" ;
                xspace:start = 0. ;
                xspace:spacing = "regular__" ;
                xspace:alignment = "centre" ;
                xspace:comments = "X increases from patient left to right" ;
                xspace:units = "mm" ;
                xspace:varid = "MINC standard variable" ;
                xspace:length = 128 ;
                xspace:step = 2. ;
        double yspace ;
                yspace:version = "MINC Version    1.0" ;
                yspace:vartype = "dimension____" ;
                yspace:start = 0. ;
                yspace:spacing = "regular__" ;
                yspace:alignment = "centre" ;
                yspace:comments = "Y increases from patient posterior to anterior" ;
                yspace:units = "mm" ;
                yspace:varid = "MINC standard variable" ;
                yspace:length = 128 ;
                yspace:step = 2. ;
        double zspace ;
                zspace:version = "MINC Version    1.0" ;
                zspace:vartype = "dimension____" ;
                zspace:start = 0. ;
                zspace:spacing = "regular__" ;
                zspace:alignment = "centre" ;
                zspace:comments = "Z increases from patient inferior to superior" ;
                zspace:units = "mm" ;
                zspace:varid = "MINC standard variable" ;
                zspace:length = 128 ;
                zspace:step = 2. ;

// global attributes:
                :ident = "gdevenyi:monster:2020.04.09.13.15.11:5337:1" ;
                :minc_version = "2.4.05" ;
                :history = "Thu Apr  9 13:15:11 2020>>> make_phantom -voxel_range -128 127 -signed -byte -clobber test.mnc\n",
                        "(mni_autoreg 0.99.70)\n",
                        "" ;
data:

 image-min = 0 ;

 image-max = 1 ;

 xspace = 0 ;

 yspace = 0 ;

 zspace = 0 ;
}
13:15:12 [gdevenyi@monster:/tmp] [base] $ mincstats test.mnc 
File:              test.mnc
Mask file:         (null)
Total voxels:      2097152
# voxels:          2097152
% of total:        100
Volume (mm3):      16777216
Min:               0
Max:               1
Sum:               20336
Sum^2:             20336
Mean:              0.009696960449
Variance:          0.009602933986
Stddev:            0.097994561
CoM_voxel(x,y,z):  64 64 64.5
CoM_real(x,y,z):   128 128 129

Histogram:         (null)
Total voxels:      2097152
# voxels:          2097152
% of total:        100
Median:            0.0004975757599
Majority:          0.00025
BiModalT:          0.00025
PctT [  0%]:       0.00025
Entropy :          0.07877741944