Hello Phil,
From one of my friends I got a *.jpg image taken with a Nikon camera.
In order to see the internal structure, I made some output e.g. with -htmldump option and a second one with -a -v3 -all:all.
All went fine.
For further tests I added - with Exiftool - some GPS, IPTC, XMP and also MWG tags.
Then I tried to get again the output with -htmldump and also -a -v3.
But now Exiftool reports a warning: Error reading PreviewImage from file
As all changes have only be done with Exiftool I ask you to have a look into the file(s).
Because of the filesize, I feeled free to send them via mail.
I performed my tests with the windows version of Exiftool 9.32.
Thanks in advance
Herb
Hi Herb,
Thanks for this report, and for the samples. The problem is that your "original" image has already been modified by some other software, and the Preview image is already lost:
% exiftool Test_jpg_Nikon_xmp.jpg_original -previewimage
Warning: [minor] PreviewImage is not a valid JPEG image - Test_jpg_Nikon_xmp.jpg_original
However, one would expect ExifTool to warn about this when writing the image, but it doesn't. I will look into this and report back when I have figured it out.
- Phil
Edit: I have taken a look. Handling the PreviewImage is very tricky, and it is common for other software to remove the preview. I think this may be the reason that I'm not issuing a warning here. I certainly could add a warning, but I don't want to at this point because I fear that many ExifTool users would then start getting warnings that they don't care about for all of their images.
Edit2: Fixed typo
Hello Phil,
thanks for your quick reply and for the investigations.
I regret that I opened the thread. But I really thought that the original image was only copied from the camera.
I also have some good news:
- Exiftool deleted the previewImage of the "corrupted image" without any errors or warnings,
- Exiftool added another "preview image" into that image, also without erros or warnings.
- I got an un-modified image (from that Nikon camera) and I have seen no problems adding tags.
Sorry again for causing these troubles.
Best regards
Herb