IPTC/EXIF and Keywords

Sorry about my english
My aim would be to be able to modify the tags EXIF/IPTC of the photos across G2. For this, I have been reading these two threads:
http://gallery.menalto.com/node/29607
http://gallery.menalto.com/node/38737
The two are related to the topic of the tags EXIF/IPTC, but I see that there are several ideas that I have not still had very clear. Probably with help of the developers, we might detach a series of targets and the steps to be able to implement them.
To help to define these aims, the following questions happen to me:
a. If a photo has tags EXIF/IPTC:
1. Do we want that all tags EXIF/IPTC would be stored in the DB or only some?
2. How would they be stored in the BD?, would new tables be created?, would add to themselves new fields in tables already existing (which?)?
3. How would integrate into the DB the existing information of G2 (commentary, title, keywords) with the tags EXIF/IPTC?, would be stored separately or would the tags and similar fields be unified?, if they are unified, would the tags of the photo be modified also so that it remains reflected in this one?
4. How would the searches be made?, would there exists possibility of looking based on values of all the types of tags EXIF/IPTC?, just as in previous point, how would be related the searches of tags to the G2?

b. If a photo does not have tags EXIF/IPTC:
1. Do we want that they can be added?, do we want that automaticaly the data of G2 (comment, title, ...) would be added in the similar tags of the photo?

Well, the truth is that I do not know if I have explained it well, but it would be good that the same questions someone can divide them in mas clearer targets.
My idea is that it is possible to allow everything previous and that is the user the one that can choose what to keey and how to search.
After the aims have remained clearer, I would like that someone could explain a series of steps to carry out them, as the files that it is necessary to modify and in what order.
Would it be possible?

Would it be possible to view and participate in the improvemente of this module?

as I see it, ColoredPixels will most probably cover the read/write exif module extension (multiple libs can be used, not just the current php based library which can only read, and is not very reliable at that). we'll see.

of course you can add suggestions. e.g. if you find a php based exif/iptc library that can read and write exif / iptc and is reliable, that would be great.

i'd welcome any help in extending the exif module to make exif / iptc tags searchable:
- as explained on the first page of this thread, we need a db Map table to hold the itemId, tagName, value mappings
- then we need an implementation of the SearchInterface_1_0 (see comment/module.inc performFactoryRegistration)
- and maybe admin options to define which fields are searchable
- and we could offer an itemeditoption to copy data from exif to the item (and later also the other way around)
- and maybe a maintenance task to do this for all items at once

All sounds quite excellent. Will poke around for an iptc lib to do as you suggest.

Another feature that extends beyond the searchable exif fields would be to extract from the EXIF and create or populate the description fields for G2, and for all the search engine bots that tear through sites looking for this meta information.

Termitenshort, there already is an interface in exif module that may help.. you can use it like this:

    list ($ret, $exif) = GalleryCoreApi::newFactoryInstance('ExifInterface_1_0');
    if ($ret->isError()) {
        return array($ret->wrap(__FILE__, __LINE__), null, null);
    }
    if (isset($exif)) {
        list ($ret, $exifData) = $exif->getMetaData($itemIds);
        if ($ret->isError()) {
            return array($ret->wrap(__FILE__, __LINE__), null, null);
        }
    }

See phpdoc in modules/exif/classes/ExifInterface_1_0.class

The interface just returns the gathered exif data.. not sure if GPS is included in that.

exifTool (perl) (http://www.sno.phy.queensu.ca/~phil/exiftool/) supports the GPS extension of exif. coloredpixels is looking into this lib mostly because of its write capabilities.
don't know if it's specific to exifTools, but there the GPS data is stored in a separate IFD, see http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/GPS.html

according to http://www.jakeo.com/software/exif/index.php
our exifer 1.4 already has GPS parsing capability (v1.3, we've got 1.4)

so we just need to know where to look for it.

Termitenshort
did you copy exif/classes/ExifExtractor.class as an example?
i'd start by outputting all exif raw data and then check what IDF / key you need.

please link to an jpeg with gps exif data.

I got it !!

I've added this

	$data['GPS/Latitude'] =
	    array($gallery->i18n('GPS/Latitude'), 'GPS.Latitude');

To the exifhelper.class and I got the EXIF module to display the GPS coordinate (At least the latitude) :D

I guess I need to modify the EXIF-module slightly (i hope it's not a big deal ?)

-------------------------
The Termite

Allright ... fumbled a bit more (in the last few sec ...) and I found that this works:

	$data['GPS/Latitude'] =
	    array($gallery->i18n('GPS/Latitude'), 'GPS.Latitude');
	$data['GPS/Longitude'] =
	    array($gallery->i18n('GPS/Longitude'), 'GPS.Longitude');
	$data['GPS/LatitudeRef'] =
	    array($gallery->i18n('GPS/Latitude Reference'), 'GPS.Latitude Reference');
	$data['GPS/LongitudeRef'] =
	    array($gallery->i18n('GPS/Longitude Reference'), 'GPS.Longitude Reference');

BUT i don't know how to format this . when i use the EXIFER thing lat.lon shows up as a decimal number (which is what I want) but when I do what's above I get dgree,minute,second....

Do you know how to format the output using the exifer library ?

Thanks in advance
-------------------------
The Termite

Well I wanted to have just a number. google is expecting a decimal xxx.xxxxxxxxxx for longitude and latitude. I made a dirty formula that transform the degree, etc to decimal but I know exifer can do it so i'd rather use the builtin function if possible

Thanks for the quick reply

Otherwise, is it ok if I modify the EXIF module or someone else should be doing it ?
If it's ok, should I make another version for people to download and upgrade ? (i that's the case I would add all of the GPS information in of course)

--------------------------
The Termite

ok, added the whole 31 keys. available in tomorrows nightly snapshot of G2.
note: sf.net anonymous cvs is still badly out of sync, state of Friday morning.

Valiant,

is the exif write module still being worked on? I would like to write copyright info to my pictures. coloredpixels should be working on it but I have no idea where to see the status of his work

regards

There is a PHP Library that can write EXIF data located at http://pel.sourceforge.net/ . A problem is that it requires PHP5, and it is still beta. I have been playing around with it, I can sucessfully edit/add EXIF data, but I am not familiar enough with the gallery API to create a module.

Just a quick note:
i've just added 'basic' database features to the current (as of release of G 2.1.0) version of exif module:
- admins can set in moduleconfig what exifProperties to store in the database
- it gets automatically stored on itemUpload
- all the storen data is searchable from the general search interface

it needs some additional steps, maybe finetune too, then i'll 'release' it here as it is.