OPT: in the padding: adapt the origin of the image in the qform and sform matrix of the header
OPT: in the padding: adapt the origin of the image in the qform and sform matrix of the header

Former-commit-id: ae5dfb7396ad5ce7e582729a1eac1e9705f8dff5 [formerly e1a887bc78bf5469561374b76102b0c493b177fc]
Former-commit-id: 25e31d8879f6982c4b4cec2d324239259b978361
Former-commit-id: 066b4a049960998ea6dbc03fb1af5edfd9513ef9
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox