Author Topic: "Capsule" question  (Read 4279 times)

silversleevesx

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"Capsule" question
« on: February 04, 2014, 10:28:10 AM »
MIE and Exiv2 .exv files: comparable? Or is it better to use XML or JSON to save metadata (IPTC, EXIF, JFIF comment as well as XMP) to a smaller file for editing and writing back to the original file?

I suppose I should state here that the "scope" of my work, as you might expect from someone who's used Exiv2 as long as I have, is JPEGs, TIFFs and the occasional PSD or PNG. In this case, my question(s) applies to JPEGs.

I hope my question was clear enough.

BZT

Phil Harvey

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Re: "Capsule" question
« Reply #1 on: February 04, 2014, 11:12:22 AM »
ExifTool .EXIF files are directly comparable to Exiv2 .EXV files (only the header is different I believe, although if .EXV files are limited to 64kB then this would be another difference).  MIE files have additional features, but these probably aren't very useful to you since you are just preserving JPEG metadata.  XML and JSON are both limited to UTF-8, so native binary data must be recoded, which makes these a cumbersome alternative if you need to store large chunks of binary data (ie. preview images).

- Phil

Edit: Fixed typo
« Last Edit: February 06, 2014, 07:44:00 PM by Phil Harvey »
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

silversleevesx

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Re: "Capsule" question
« Reply #2 on: February 06, 2014, 06:48:11 PM »
Thank you, Phil, for the explanation and quick & courteous reply. I've been making .exv's of the JPEGs I've been editing on my Linux laptop (2GB RAM) of which the originals are on my Windows desktop (same RAM and too much running in it; 2 dead RAM slots on an interleaved motherboard), file-sharing the .exv's back to said box, applying them in Cygwin, then running a bash script to write the XMP titles in Exiftool so the XMP looks like it should in the browser XMP tab of XnView Windows. Understandably, I was looking for an "all-Exiftool" way of doing this.

BZT

silversleevesx

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Re: "Capsule" question
« Reply #3 on: February 06, 2014, 07:52:40 PM »
I've created an .exif file which, by file length, appears to have all the tag & label data of the original JPEG. Seems I've forgotten how to write back from such a file to its source, if I ever knew how in the first place. )-:

I've blanked, and not just the JPEG that was the source file in this instance.

BZT

Phil Harvey

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Re: "Capsule" question
« Reply #4 on: February 07, 2014, 07:22:57 AM »
There are a number of ways.  This command will copy the tags back, preserving the original groups:

exiftool -tagsfromfile src.exif -all:all dst.jpg

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

Phil Harvey

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Re: "Capsule" question
« Reply #5 on: February 07, 2014, 09:56:50 AM »
I just took a look at the EXV file.  It is a JPEG file with a different header and no image.  Just for the fun of it, and because it is easy, I will add support for this format.  ExifTool 9.50 (probably to be released tomorrow) will be able to read, write and create these files.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

silversleevesx

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Re: "Capsule" question
« Reply #6 on: February 07, 2014, 11:24:17 AM »
I just took a look at the EXV file.  It is a JPEG file with a different header and no image.  Just for the fun of it, and because it is easy, I will add support for this format.  ExifTool 9.50 (probably to be released tomorrow) will be able to read, write and create these files.

- Phil
Phil,

Thanks for taking another look at .exv files. W/re upgrading: my concern is not so much the version of Exiftool as it is of Perl that supports it. If I knew which versions and builds were needed to run the newer versions of Exiftool, I'd get them and upgrade both. I've found you can do a lot with a library card and a USB thumb drive, for example. And you've certainly given me a reason to bring my Perl installs, etc, up to date.

Thanks again for the quick reply.

BZT

Phil Harvey

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Re: "Capsule" question
« Reply #7 on: February 07, 2014, 11:47:06 AM »
My goal is to keep ExifTool compatible with all Perl versions back to 5.004

To date, ExifTool 9.46 has passed all tests in 455 reports with Perl versions from 5.6.2 to 5.19.9 on various platforms.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

Phil Harvey

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Re: "Capsule" question
« Reply #8 on: February 07, 2014, 09:24:11 PM »
I was playing around with EXIF files and had forgotten that I have set them up to store on EXIF information (and not IPTC or XMP), so they aren't analogous to Exiv2's EXV files.  Sorry.  I got this wrong when I recently created the table of supported metadata too.  I'll fix this.

You would have to go to MIE files (or EXV files after ExifTool 9.50 is released) to be able to store EXIF, IPTC and XMP in one file.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

silversleevesx

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Re: "Capsule" question
« Reply #9 on: February 08, 2014, 03:48:34 AM »
Phil,

I noticed that, too, in 8.77. As for MIE files, am I right in supposing:
1 - They're editable via Exiftool? (I believe the man page said they were)
2 - A similar command to the one in your last reply writes the edited tag data back to the source JPEG (or TIF or PSD) file?
Here I'm being careful and not "forging ahead" like last time. If I hadn't also made an .exv for the one JPEG I tried this on (in between two previous posts), I would have had to start from scratch. I believe there' s something one might call the "man page eye," and too often mine is sorely lacking in sharpness.

BZT

Phil Harvey

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Re: "Capsule" question
« Reply #10 on: February 08, 2014, 06:10:34 AM »
Yes, MIE files are editable, and the command is exactly the same but with a .mie extension.

I'll be releasing 9.50 with EXV support within a couple of hours.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).