png_set_filter    682 contrib/libtests/makepng.c       png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters);
png_set_filter   3827 contrib/libtests/pngvalid.c                png_set_filter(pp, 0/*method*/,
png_set_filter   1586 png.h          PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
png_set_filter   2270 pngwrite.c           png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);