PNG_FILTER_NONE  1315 contrib/libtests/makepng.c          filters = PNG_FILTER_NONE;
PNG_FILTER_NONE  1462 contrib/libtests/makepng.c          filters = PNG_FILTER_NONE;
PNG_FILTER_NONE  1467 contrib/libtests/makepng.c             filters &= ~(PNG_FILTER_NONE | PNG_FILTER_AVG);
PNG_FILTER_NONE  1474 contrib/libtests/makepng.c          filters &= ~PNG_FILTER_NONE;
PNG_FILTER_NONE  1600 png.h          #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
PNG_FILTER_NONE  1014 pngwrite.c                 png_ptr->do_filter = PNG_FILTER_NONE; break;
PNG_FILTER_NONE  1109 pngwrite.c                 png_ptr->do_filter = PNG_FILTER_NONE;
PNG_FILTER_NONE   342 pngwutil.c              else if (png_ptr->do_filter != PNG_FILTER_NONE)
PNG_FILTER_NONE   909 pngwutil.c              png_ptr->do_filter = PNG_FILTER_NONE;
PNG_FILTER_NONE  2386 pngwutil.c        if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE)