-use MWG and Panasonic RAW

[Mac2]

I today stumbled upon a (documented) side effect of enforcing MWG compliance when reading data from Panasonic RW2 files via exiftool.exe.

ExifTool reads the data but skips quite a bunch of tags with the warning message:

Warning: Ignored non-standard EXIF at TIFF-IFD0-JPEG-APP1-IFD0 -

The tags skipped are important for my users because they contain lens information, serial number etc.

To import the information anyway, I used the FAQ trick and added the $Image::ExifTool::MWG::strict = 0 to a custom config file.

Besides allowing my software to import the skipped tags, are there any potentially harmful side effects caused by this setting? I want MWG compliance if possible because everything that brings some order in this metadata mess is most welcome.

[Phil Harvey]

Disabling strict MWG has no effect other than enabling reading of non-standard EXIF, IPTC and XMP, so it will have no effect when reading files that only contain metadata in the standard locations.  The only time it would be a problem is if the image contains non-standard metadata which conflicts with other information.

The RW2 format is a bit funny.  Because it is a TIFF-based format, the "standard" location would be in the TIFF IFD0 and ExifIFD.  But instead, Panasonic puts the information in a JPEG image embedded in the TIFF.  For these files, you are certainly safe disabling the strict MWG conformance.

But maybe add the RW2 files as a special case.  I'll think about this.

- Phil

[Mac2]

The RW2 format is a bit funny.

The more I work with metadata the less funny it gets

I by default enforce MWG conformance in my application and also use whatever else ExifTool has to offer to clean up and sanitize metadata.

If this is a special case only for RW2 files, perhaps ExifTool could treat it as such, allowing us to keep the defaults for MWG compliance without the need to use a custom config.