[IMAGING-258] TiffReader.readDirectories() fails on EXIF data

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.0-alpha1
• Fix Version/s: 1.0-alpha2
• Component/s: Format: TIFF
• Assignee: Bruno P. Kinoshita
• Reporter: Gary Lucas
• Created: 28/May/20 14:06
• Updated: 07/Aug/20 04:24
• Resolved: 12/Jul/20 11:01

Description

When reading a TIFF directory that contains an EXIF sub directory, the TiffReader class throws an ImageReadException stating that "ExifOffset has incorrect type IFD". 

This exception occurs in the TiffReader.readDirectories() call which attempts to read all IFD's (directories) in a TIFF file.  It can be avoided by calling TiffReader.readFirstDirectory().  Of course, if you do that, you will not be able to access the EXIF elements.

This happens when accessing the TIFF element with TIFF Tag 0x8769.  I suspect that it could also happen with TIFF files containing GPS extensions, Tag 0x8825.

I've gotten this issue with GeoTIFF files from a couple of different sources.  The one I'd recommend for testing would be the public-domain "Natural Earth Data"  medium-size Cross-blended Hypsometric Tints file at https://www.naturalearthdata.com/downloads/10m-raster-data/10m-cross-blend-hypso/

I am not experienced with the EXIF sub-directory specification and do not yet have a good sense of what the level of effort for a fix would be.