[DO.Core] MAINT: remove unneeded comments.
[DO.ImageProcessing] BUG: fixed cmake config file.
[DO.Graphics] FIX: corrected implementation.

This fixes a corner case at the expense of being slower. This really
needs to be reviewed!!!
[DO.Graphics] BUG: compilation fix.
MAINT: reactivate all test suites.
FIX: corrected unit tests.

TODO: review unit tests. They are not implemented rigorously.