The underscore is sometimes used to separate components of long function names. Constness is preserved were possible. Functions needed for operations on individual pixels are inlined. Functions needed for operations on whole images are not inlined. This may change if compilers are getting smarter about generating multiple copies of inline functions.
Error handling is simplistic.
If it is possible to proceed the errors are silently ignored. The advantage of this scheme is that no error values need to be checked in user programs. Go to the first , previous , next , last section, table of contents .