XnView 1.94 Recreate EXIF Thumbnail corrupted photos

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LMan
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Joined: Tue Jan 02, 2007 6:15 am

XnView 1.94 Recreate EXIF Thumbnail corrupted photos

Post by LMan » Wed Jul 23, 2008 5:45 pm

Dear XnView team,

I updated to 1.94, and as I usually do I chose the batch-remake EXIF thumbnails on a bunch of photos. 16 of 100 were during that process corrupted in a way that they couldn't be read afterwards by any software (including XnView). :bug:

I blame myself for not making backups of my holiday photos before doing any batch processing, but such a thing never happened before and I grew careless... :(

Here's one of the corrupted images, maybe it helps tracing the bug:
https://sandbox.dev.intersolute.de/~mkl ... uption.jpg

Thanks and keep up the great work...
Kind regards
Markus

PS: If there is any way to recover the images, I'd be happy to learn of it...!

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XnTriq
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Post by XnTriq » Wed Jul 23, 2008 6:40 pm

XnTriq ([url=http://newsgroup.xnview.com/viewtopic.php?p=64293#64293]Lossless JPEG cropping doesn't change date/time stamp[/url]) wrote:
  • Select the thumbnail and go to Edit » Metadata » Recreate EXIF thumbnail.
    • :bug: If you try to open dc0a73e8e6.jpg again, you'll notice that it is kaput.

LMan
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Post by LMan » Wed Jul 23, 2008 6:47 pm

Thanks for the info... :)

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Dreamer
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Post by Dreamer » Wed Jul 23, 2008 10:34 pm

Moved to Bug Reports.
Dreamer

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XnTriq
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Re: XnView 1.94 Recreate EXIF Thumbnail corrupted photos

Post by XnTriq » Thu Jul 24, 2008 12:30 am

LMan wrote:PS: If there is any way to recover the images, I'd be happy to learn of it...!
LMan, would you like me to upload the repaired image to a file-sharing host and send you the link via PM?
  1. Feeding exif_thumb_corruption.jpg to jhead.exe v2.82 with the -purejpg option in order to “strip all unnecessary data from jpeg” didn't help.
  2. An examination of exif_thumb_corruption.jpg with JPEGsnoop v1.2.0 revealed the following:
    • Model = Canon DIGITAL IXUS 80 IS
      Image Size = 2448 x 3264
      Raw Image Orientation = Portrait
      ERROR: Read more than specified EXIF thumb length (5172 bytes) before EOI
  3. I went hunting for an unaltered/unedited photo taken with the same camera at the same resolution & orientation as exif_thumb_corruption.jpg:
  4. After downloading 08299l.jpg I removed all metadata from it with XnView v1.39.6 (Edit » Metadata » Clean...).
  5. Using a hex editor I replaced the first 10369 bytes of exif_thumb_corruption.jpg with the first 158 bytes from 08299l.jpg.

LMan
Posts: 8
Joined: Tue Jan 02, 2007 6:15 am

Post by LMan » Thu Jul 24, 2008 5:59 am

Wow, you went through all that trouble and found a solution!! Image

Thanks so much, don't bother sending back the one you fixed, you've helped so much already - I'll retrace the steps to fix the images.

I would like to express my gratitude and will do a paypal donation. I can't give much, but it is from the heart. :)

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xnview
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Post by xnview » Thu Jul 24, 2008 4:43 pm

IT's a severe bug, who want to test the fix? (send your email by PM)
Pierre.

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