EXIF, IPTC, CS File Info tags/fields OVERVIEW

[Jonathan]

1. Can anyone point me to a website or article that provides an authoritative overview of the various image info field/tag system/conventions (IPTC, EXIF, XMP Adobe CS File Info)?
2. Which fields are saved in which image format (jpg, jp2, tif, gif, raw, crw, cr2)?
3. When Adobe CS reads a file, from where does it get the fields it reports in its File Info dialogs?
4. If you edit CS File Info dialogs, where are they stored in the image (IPTC or EXIF?)?

In my work, which involves collaborating with a number of people, I have to use various programs (Adobe CS, BreezerBrowser 2.11, ACDSEE 7.0, Portfolio 6.0, Imatch). Tags entered in one program don't transfer to others, same "tag" seems to be named different things in different programs (especially "comment"), some seem to be unique to particular programs...all very confusing.
Trying to figure it out by trial and error is driving me nuts. Does anyone understand it all?
Jonathan

[Evo2Me]

Neither is extensive but I've found nothing better yet:

http://www.controlledvocabulary.com/imagedatabases/index.html
http://www.iptc.org

Adobe may have something on their Web sites, look for XMP (datasheet).

[it's a lifestyle thing]

I only recently started using DL Pro to add the IPTC data, and as good as DL pro is for this, it's annoying that other software then wipes the data out of the file.

In testing this I compiled a table below;
Taking a cr2 file from Canon 1d Mk2 or 20d, added IPTC Data with DL Pro.
1. Using Canon EOS File Utility 1.2.1
2. Using Adobe Camera Raw 2.4
3. Using BB Pro 1.1.1

Saving to Jpg:- 1 kept exif lost iptc, 2 kept iptc and most exif, 3 kept both exif and iptc.
Saving to Tiff 16 bit:- 1 kept basic exif lost iptc, 2 kept iptc and basic exif, 3 kept exif only lost iptc.

If anyone has a way to get the IPTC data back - e.g. saving it into a text file and re-applying or copying from one folder of images to another - i would like to hear it.

Regards,
Kev

[Chris Breeze]

You can use the EXIF copy function in BBPro to copy EXIF and IPTC data to the converted images.

BTW BBPro does store both EXIF and IPTC data when saving 16-bit TIFFs.

The big problem with IPTC data is the standard only specifies how to encode the data but doesn't specify how it should be stored in various image types. The result is there are several rival methods. You sometimes end up with IPTC data being stored multiple times which then becomes a nightmare when it is edited because the different copies of the IPTC data become out of sync.

[it's a lifestyle thing]

Apologies for the mistake concerning 16bit-tiff and iptc data - it does stay when converting from BB Pro as Chris pointed out.

Regards,
Kev

[HenriMonnier]

I have been plauged by those annoying losses for a while, and have modifed my workflow accordingly: after I have determined which images I am going the save (prior to any editing), I always run through BBPro using the EXIF copy function to generate a seperate .txt file for each image file.

This has 'bailed me out' a couple of times. I keep the .txt files within the same folder as the images, and they are included in my weekly (or more often) backup process.
Henri Monnier

[Chris Breeze]

You could also create small JPEGs in a separate folder to backup the EXIF and IPTC data. This would allow you to copy the EXIF data back to the edited image if it gets lost during the editing process.

[joslawrence]

Hello,

I recently have discovered and begun to use BB to restore my EXIF data to images that have been converted with other software or edited with software that does not preserve the camera specific information. While certainly not an authoritative discussion of EXIF data I have written a brief article about this on my website which can be viewed at: http://www.creationview.com/Art-2.html