PNG_FORMAT_NUMBER  717 png.c                   APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value)))
PNG_FORMAT_NUMBER  259 pngerror.c        png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
PNG_FORMAT_NUMBER  275 pngerror.c        str = PNG_FORMAT_NUMBER(buffer, format, u);