[Originally posted by fpietri on 2007-03-22 21:43:00-07]
Hi Phil and all,
I'am experiencing problem with makernotes offset when I geocode photos with Picasa-Google Earth...
Have you noticed this problem with Picasa?
Is picasa a poor Exif writer?
Even the -F argument can't fix makernotes offset by default.
[Originally posted by exiftool on 2007-03-22 22:35:47-07]Many Exif writers have this problem.
When you say -F doesn't fix it, what exactly do you mean? Using
-F should allow you to read the original makernote information.
If you rewrite an image using the -F option, you still have to use
-F on the resulting image to properly read the maker notes.
To repair it permanently, you need to rebuild the makernotes by
copying them into themself. ie:
exiftool -F -tagsfromfile @ -makernotes FILENAME
- Phil
[Originally posted by fpietri on 2007-03-23 06:43:27-07]Thanks for your answer.
When I try to fix makernotes with -F option, makernotes data are still corrupted.
There are two hypothesis:
* the fix offset that exiftool calculate is incorrect.
* original makenotes are broken or partialy deleted by Picasa.
You will find in a few minutes, three files (original, processed by picasa with GPS info, fixed by exiftool) at this address
Here
[Originally posted by fpietri on 2007-03-23 06:52:30-07]Thanks for your answer.
When I try to fix makernotes with -F option, makernotes data are still corrupted.
There are two hypothesis:
* the fix offset that exiftool calculate is incorrect.
* original makenotes are broken or partialy deleted by Picasa.
You will find in a few minutes, three files (original, processed by picasa with GPS info, fixed by exiftool) at this address
Here
[Originally posted by exiftool on 2007-03-23 11:45:04-07]
Ouch. ExifTool is calculating an incorrect fix offset for your camera because it
appears that Canon has changed the base position of the first entry in the
makernotes with a firmware update. For firmware 1.0.1, the first value was
6 bytes from the end of the makernote IFD, but with your camera (firmware
1.0.3) it is only 4 bytes. Darn. This means the fix offset is 2 bytes too high
for your camera. So you can recover the information for this specific image
with "-F11" (which adjusts the offsets by 11 bytes instead of the suggested
13). I will see if I can fix this problem in the next ExifTool release.
So the makernote information isn't lost.
But your utility is doing something else that is a clear violation of the TIFF/EXIF
specification. This is a problem I have seen in utilities where the programmer
didn't read the TIFF specification: All TIFF offsets must be even, and all
values must be stored on word boundaries. Your edited file violates this.
- Phil
[Originally posted by fpietri on 2007-03-23 11:53:51-07]OK thanks for your answer.
Just one more thing, be aware that the original jpg file is in fact a RAW file developed with DXO, I forgot to tell you that.
Perhaps is DXO who change the base position of the first entry in the makernotes.
I post the original RAW file in my
website if you want to check that.
[Originally posted by exiftool on 2007-03-23 12:21:49-07]
Ah ha! Thanks. This makes sense now. I was concerned because Canon
is usually very consistent in their writing of the maker notes. In fact,
Canon is the one make where ExifTool has the best success in restoring
corrupted maker note offsets.
DXO is changing the position of the first entry when it rewrites the
makernotes for the JPEG image. The position in the original CR2
image is 6 bytes from the end of the makernotes IFD as expected.
However, I will still look into adding the logic to detect images
with rewritten maker notes like this.
- Phil
[Originally posted by exiftool on 2007-03-23 15:37:18-07]I've made an improvement that allows the modified and corrupted Canon
makernotes information to be properly extracted.
Recent Canon models (including your 350D) add extra information to the
end of the makernotes that allows the original position of the makernotes
block to be determined. I haven't been taking advantage of this information
because until now my more general technique has worked well. But now I
have added the specific logic to use this information if available, and apply the
fix automatically since this should be a more reliable technique to determine
the true offsets.
This feature will appear in version 6.83, and I have uploaded a pre-release
hereif you want to try it out before the official release.
- Phil
[Originally posted by fpietri on 2007-03-23 15:50:37-07]
Wahou.
Exiftool support is the best software support I ever seen.
Thanks a lot Phil.
[Originally posted by melabergmann on 2007-12-08 18:48:16-08]
I have a similar problem. exiftool tells me that my pictures have:
[minor] Possibly incorrect maker notes offsets (fix by -184?)
I tried your solution. exiftool then said:
-------------
$ exiftool -F -tagsfromfile @ -makernotes CIMG4834.JPG
Warning: [minor] Adjusted MakerNotes base by -184 - CIMG4834.JPG
Error: Can't read InteropIFD data - CIMG4834.JPG
0 image files updated
1 files weren't updated due to errors
-------------
What am I doing wrong?
[Originally posted by exiftool on 2007-12-08 19:28:58-08]
It sounds like your image has more than one problem. Use the -a
option to display all warnings. My guess is that you will get a InteropIFD
warning as well as an "incorrect maker notes offsets" warning for the
original file. If so, the problem is more serious. Your option here may be
to delete the InteropIFD with "interopifd:all=". You should then
probably rebuild the InteropIFD from another file.
If this doesn't work, send me a copy of the image and I'll be able to
help more. (philharvey66 at gmail.com)
- Phil
[Originally posted by melabergmann on 2007-12-08 20:03:30-08]
Hi Phil, thank you for your quick reply. I tried your suggestions on several files. There seem to be various error messages. Some files are ok, some with
Warning: Bad InteropIFD directory - CIMG0403.JPG
Some with the Maker Notes error described above.
To describe my situation: I have approx. 1000 images in 20 galleries. Each gallery contains pictures from different users with different cameras and different software tools. Now I want to import them into my Content Management System and use the PEL-Library to read the Original Creation Date in order to sort the pictures. I don't need the other meta information.
Do you have an idea how to achieve that? Automatically delete all corrupt information, but keep the correct Creation Date info?
My best regards, Melanie
[Originally posted by exiftool on 2007-12-08 20:29:21-08]Hi Melanie,
If this is the only meta information you need, then it would be
possible to delete everything except for the common date tags
with the command:
exiftool -all= -tagsfromfile @ -alldates DIR
but that is a bit extreme. I would prefer rebuilding the meta
information like this:
exiftool -all= -tagsfromfile @ -all:all DIR
(where DIR is the directory containing the images)
This should fix the problems you are seeing in JPEG images,
although it will not copy any "unsafe" tags, so they will be
deleted from the image. (This includes interopifd tags)
- Phil
[Originally posted by melabergmann on 2007-12-08 20:57:12-08]
Thank you! This one works perfectly. You saved my day!