Extracting raw EXIF data from image

[StarGeek]

But that command should copy the MakerNotes as a block for most common makes.

Ah, my mistake then.

[ExploreCams]

I can't answer this 100%.  It depends on the models of cameras used to generate the images, and the softwares used to process them afterwards.  Some cameras may not be supported, and some software may make a huge mess of the metadata.  In both of these cases you may lose some information.  I suggest trying this out on a cross-section of representative samples to satisfy yourself that it is doing what you want for your files.

- Phil

Hey Phil, so I did some testing and found the problem where the actual Lens information is lost when trying to parse it from MEI.

That's the test image:
https://cdn.explorecams.com/storage/test/explorecams-1347.jpg

So when I do the following:

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exiftool -z -tagsfromfile explorecams-1347.jpg -all:all -icc_profile tamron.mie
exiftool tamron.mie

Lens ID output is "15.0-30.0mm f/2.8"

but when I am doing:

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exiftool explorecams-1347.jpg

Lens ID output is "Tamron SP 15-30mm f/2.8 Di VC USD (A012)"


What I am missing here? Please advice.

[ExploreCams]

Hm, but when I do this I can read the correct lens from the MIE file.

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exiftool -tagsfromfile explorecams-1347.jpg -exif -xmp -iptc -makernotes -icc_profile tamron6.mie



I thought -all:all is the same as -exif -xmp -iptc -makernotes -icc_profile ... is there any other directives that could be included to get any other possible metadata bits extracted? It is pretty hard to find anything about it in the documentation. :-)

[StarGeek]

XMP-aux:LensID isn't being copied with All:All.

[ExploreCams]

XMP-aux:LensID isn't being copied with All:All.

Do you have any idea why? Is there any additional command that would complement all:all command and extract raw metadata bits from the image into a file?

[Phil Harvey]

Ah.  ExifTool rejects the XMP-aux:LensID because it is negative.  I'll patch the next version to allow negative numbers.

- Phil

[ExploreCams]

Ah.  ExifTool rejects the XMP-aux:LensID because it is negative.  I'll patch the next version to allow negative numbers.

- Phil

Oh, are there any other rules / limitations that get rejected when all:all is used? This does not happen when I do define -xmp in the command line.

[Phil Harvey]

-all:all copies tags individually, so each tag has a chance to do some validity checking if it wants.  Also, only writable tags will be copied with -all:all, so for XMP it is more complete to copy it as a block (provided its size is below 64kB because you run into complications with JPEG segment size limitations if it is larger than this).

- Phil

[ExploreCams]

-all:all copies tags individually, so each tag has a chance to do some validity checking if it wants.  Also, only writable tags will be copied with -all:all, so for XMP it is more complete to copy it as a block (provided its size is below 64kB because you run into complications with JPEG segment size limitations if it is larger than this).

- Phil

Oh I see. I missed the whole concept of the -all:all . I thought it was an alias for all the available metadata blocks (-XMP, -IPTC, etc...). Is there any such exiftool command line that would check for existing blocks and copy them as a whole?

[Phil Harvey]

Hi Linas,

Is there any such exiftool command line that would check for existing blocks and copy them as a whole?

No, but there aren't many blocks available for copying.  There are all listed in the Extra tags.

- Phil

[ExploreCams]

No, but there aren't many blocks available for copying.  There are all listed in the Extra tags.

Thanks Phil.

So I did come up with the following command line. Would it get the most of the metadata from the images, or I am missing some bits?

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exiftool -tagsfromfile explorecams-1347.jpg -exif -xmp -a -iptc -makernotes -icc_profile -adobe -canondr4 -canonvrd -trailer -comment -z final.mie


Also, by reading the documentation and if I understood it correctly '-a' option would extract extended XMP block. Is this right?

[Phil Harvey]

I would have to try this to see what happens with the extended XMP block, but I don't think it will handle this properly.  However, extended XMP blocks are very rare.

Also, I think -makernotes is unnecessary because it is contained in the EXIF block.

- Phil

[ExploreCams]

I would have to try this to see what happens with the extended XMP block, but I don't think it will handle this properly.  However, extended XMP blocks are very rare.

Also, I think -makernotes is unnecessary because it is contained in the EXIF block.

Thank you for your help!

I have one more question. Is it somehow possible to write a MIE sidecar and also give JSON output of the generated MIE file in a single command?

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curl -s "https://images.unsplash.com/photo-1594819167477-290dd33b4daa" | exiftool -fast -tagsfromfile - -exif -xmp -iptc -icc_profile -adobe -canondr4 -canonvrd -comment -z test.mie


[Phil Harvey]

No.

[ExploreCams]

Is it possible to have a conditional metadata extraction?

I have tried the following command without much success.

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curl -s 'https://images.unsplash.com/photo-1594819167477-290dd33b4daa' | exiftool -fast -tagsfromfile - -if '$Model' -exif -xmp -iptc -icc_profile -adobe -canondr4 -canonvrd -comment -z test1.mie


If possible I would like to avoid creating a sidecar MIE file if EXIF data does not have a Model.