Re: png++: diffs in test bench libpng12 vs. libpng16
Alex Shulgin <[email protected]>
| Newsgroups | gmane.comp.graphics.png.devel |
|---|---|
| Message-ID | <CAM-UEKQ9mZ8e_RXK4DXdbp1LfFVrk6iCV6Mf7aJqVQ_MRcpQfg@mail.gmail.com> |
On Sun, Nov 27, 2016 at 10:54 AM John Bowler < [email protected]> wrote: > On Sat, Nov 26, 2016 at 11:38 PM, Alex Shulgin <[email protected]> > wrote: > > The way that test suite is designed is that it runs a number of > conversions > > using png++ over about a 100 of pre-selected test files from the official > > pngsuite and compares the resulting files with the expected "standard" > > output files using cmp(1). > > You mean direct comparison of numerical pixel values? > No, the whole encoded files actually. That doesn't work between major releases and sometimes fails within a > single major release. It also doesn't work between different libpng > configurations; changing from floating to fixed point changes the > results as does changing the speed/accuracy configuration parameters. > > Major releases do three major things in this area: > [snip] Thank you for detailed answer, that's very helpful. Looks like I have to rethink what I really want to test and how. :-) -- Alex ------------------------------------------------------------------------------ _______________________________________________ png-mng-implement mailing list png-mng-implement-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org https://lists.sourceforge.net/lists/listinfo/png-mng-implement