Canon EOS-M: "Removed 1 invalid entry from MakerNotes"

[gmikol]

Using ExifTool to geotag images from my Canon EOS-M, firmware v2.02

exiftool.exe -v -geotag test.gpx IMG_0051.CR2

I get the following warning:
...
  Rewriting AmbienceInfo
  Warning = [minor] Removed 1 invalid entry from MakerNotes
  Rewriting InteropIFD
...

This is on Win7 x64, using the 9.35 stand-alone binary.

I've posted this in the "Bug Reports" section because these files are straight out of the camera, so there should be no "invalid" entries. My assumption is that ExifTool is just not parsing the info correctly. I'm sure this might also happen with other methods of writing/rewriting the exif, I just haven't tried to construct a synthetic example.

I'd hate to have any of the MakerNotes stuff stripped from the file, as I do use Canon's software to process the RAW files. No telling what it might break...

The CR2 file is quite large, 22MB, but it can be downloaded here:

https://www.dropbox.com/s/tniu6pw1kihrs12/IMG_0051.CR2

Sorry I don't have a smaller file as an example.

Any help is appreciated--

Greg

[Phil Harvey]

Hi Greg,

these files are straight out of the camera, so there should be no "invalid" entries.

To the contrary.  Invalid entries are commonplace in maker notes.  Use the -htmlDump feature to see what the problem is in this case.  Here, the EOS M writes an IFD entry which is all zeros.  My guess is that they do this instead of properly reformatting the IFD to remove the empty entry.  But the result is not valid EXIF, so ExifTool reports the error.  Rewriting this CR2 will remove the invalid IFD entry.  The Canon software seems to be OK with this.

- Phil

[gmikol]

Thanks, Phil...

I'll have to remember about -htmlDump the next time I run into an issue.

--Greg