Debug Options

Starting in OpenSlide 3.4.0, the OPENSLIDE_DEBUG environment variable can contain a comma-separated list of debug options that will affect the behavior of the library. Pass OPENSLIDE_DEBUG=help for a list of debug options supported by your copy.


Log the error message returned by each format driver that does not detect support for the specified slide file during openslide_detect_vendor(), openslide_can_open(), or openslide_open(). Useful if openslide_open() returns NULL when you think it shouldn’t.
For Hamamatsu VMS and NDPI slides, locate all restart markers and perform an extra verification pass before openslide_open() returns. Slow.
Log conditions causing OpenSlide to exhibit suboptimal performance.
Draw tile outlines and coordinates in openslide_read_region() output.