Gray TIFF files after embedding metadata

[stevek]

Hi,

I'm a relatively new user and I've used an older version of ExifTool (version 5) to create CSV files of file metadata and embed some additional descriptive metadata into files. I had pulled the metadata using -ALL to see everything in the files, and then rewrote the same CSV along with the descriptive updates back into the TIFF files - nothing technical was changed by me. All seemed worked fine, and Windows Photo Viewer displays the TIFFs just fine. But I discovered later when I open them in Photoshop, I get a strange gray image. I'm attempting to attach an image to this post showing the Photoshop/Window Photo Viewer displaying a sample.

This only happened to files when I embedded ALL of the pulled metadata back into them (since then I only rewrite the metadata needed and have no issues like this). Any idea of what could have changed in the metadata to cause this? I suspect Excel saw some numerical and symbol data as a formula and messed it up, but not sure.

I can "fix" these problem files by rotating and saving the TIFF in Windows Photo Viewer and then rotating it back and saving it again, which is painstakingly slow and cumbersome since these files are rather large. Since the files displayed fine in the computer initially, I unfortunately deleted the tif_original files before the issue with Photoshop arose (learned a lesson there!). Any thoughts on how to reverse this problem easily using exiftool or something else?

Thanks!

Steve

[Phil Harvey]

Send me the tiff image and i'll take a look.   My email is philharvey66 at gmail.com

- Phil

[Phil Harvey]

Hi Steve,

The file you sent will display properly in Photoshop after I remove the Predictor tag from IFD0:

exiftool -ifd0:predictor= FILE

The current version of ExifTool marks that tag as unsafe so it won't be copied by default.  I don't know if version 5 treated it as unsafe, but regardless I don't see how it could get added to your image if it wasn't there before.

- Phil

Edit:  Ah, I see now.  There is also a Predictor tag in the SubIFD, and if you didn't copy things back into the same location then it could have been written to IFD0.  I think it is likely that this is what happened.

[stevek]

Thanks Phil,

Thanks so much for looking into this problem. This will make it much easier to fix these files!

Steve