Thanks for the tip.

When I run the command on 'lh.white' surface for example, I don't get an affine transform but a simpler one:

vox2ras-tk:

-1  0 0  128

 0  0 1 -128

 0 -1 0  128

 0  0 0  1

So when I apply this transform to a pixel position (152, 66, 73) here is the result I get:

-152, 73, -66

But the expected result provided in Freeview as TkRegRAS T1 is:

-23.61, -55.02, 61.25

Which obviously involving an affine transform.

Did I miss something?

Thanks

Cheers,

Florent