png_set_write_fn 1772 3rdparty/libpng/png.h PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr,
png_set_write_fn  545 3rdparty/libpng/pngwrite.c    png_set_write_fn(png_ptr, NULL, NULL, NULL);
png_set_write_fn  364 modules/imgcodecs/src/grfmt_png.cpp                     png_set_write_fn(png_ptr, this,