exiftool TIFF identification resolution

[pwinckles]

I noticed that FITS is not reporting the PRONOM format id for our tiffs. At first I assumed it was because Droid was failing to identify the files, but this is not the case. The problem is that the exiftool format identification is suppressing the Droid identification.

The format as reported by Droid is Tagged Image File Format, and the format from exiftool is TIFF EXIF. Based on the format tree, the Droid identification is thrown out.

I dug into this further. The exiftool format is constructed here. What's interesting is that further down some of the formats that had EXIF appended to them are translated into something else. For example:

<xsl:when test="$format='PSD EXIF'">
	<xsl:value-of select="string('Adobe Photoshop')"/>
</xsl:when>

However, this is not done for TIFF EXIF. Is this intentional? Should there be an entry like:

<xsl:when test="$format='TIFF EXIF'">
	<xsl:value-of select="string('Tagged Image File Format')"/>
</xsl:when>

If not, what are your thoughts on changing the format resolution code to not throw out externalIdentifiers when resolving formats?

[pwinckles]

Okay, I believe I have identified the root cause of the issue:

1. The exiftool xslt inappropriately adds EXIF to TIFFs that have a byte-order. It's unclear to me if this is appropriate for other formats, but it's certainly in correct for TIFFs
2. JHOVE has a bug where it defaults the ExifVersion, so that all TIFFs are always identified as TIFF EXIF

[pwinckles]

Resolved by #212