Related to bob.extension#58 (closed), there are some unnecessary parameters that are passed on the compiler command line. All the versions of the dependent libraries (JPEG, TIFF, GIFF, PNG) are estimated in setup.py and passed as a -D..._VERSION to the compilation. However, on one hand, some of these values are not used in the C++ code at all, and others can be taken directly from the original header files instead of taken from the command line.

Note that these flags are not exported to other libraries on the python level, only the HAVE_... macros are, see: https://gitlab.idiap.ch/bob/bob.io.image/blob/c8ca9cddbadd56c4386cc1327427640af383110f/bob/io/image/__init__.py#L116 Hence, there will be no side-effect in removing these definitions from the command line.