How to get information about Wikimedia image?

Question

I'm trying to retrieve images from wikimedia using the existing api, but there seems to be no logic in what works and what doesn't.

Here's what i'm doing/have tried:

I'm getting a query of images, from this url.

http://en.wikipedia.org/w/api.php?action=query&list=allimages&aiprop=url&format=xml&ailimit=10&aifrom=jura

This returns an xml feed, from which i get the image names and url's:

<img name="Jura.PNG" url="http://upload.wikimedia.org/wikipedia/en/a/ad/Jura.PNG" descriptionurl="http://en.wikipedia.org/wiki/File:Jura.PNG"/>

Then, to get the information, such as uploader and license, i use this tool, as linked on wikimedia:

http://toolserver.org/~magnus/commonsapi.php

It requires the parameter ?image=, followed by a filename. Jura.PNG from the xml example, works fine. However, most other one's i try just return <error>File does not exist</error>. I've tested, the files do exist. I can't figure out why one file works, and another doesn't.

For testing, another one that works is Calumma_tarzan_01.jpg.

Does anyone know what i'm doing wrong?

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Not working examples:

Jurassic.jpg
Juramento_de_la_Primera_Junta.jpg
JuraDolois_logo.jpg

Used php code:

$xml_link = "http://en.wikipedia.org/w/api.php?action=query&list=allimages&aiprop=url&format=xml&ailimit=10&aifrom=".$search_term;
$xml = simplexml_load_file( $xml_link );
$xml_link_data = "http://toolserver.org/~magnus/commonsapi.php?image=".$imgname;
$xml_data = simplexml_load_file( $xml_link_data );
var_dump($xml_data->licenses->license);

for the Jura.PNG example the correct object is dumped, but since other urls dont have the license part, the result is obviously NULL. I think the problem isn't here, however, since manual input of the url in a browser also won't return results.

Answer 1

Wikimedia Commons is a repository of free images that Wikipedia uses. It is primarily used for sharing of images between national mutations of Wikipedia.

Many images on the English Wikipedia are used under fair use. Those are not free, so they can't be put on Commons.

The tool you have found works only on images from Commons (as its name suggests), so it can't be used for images that are hosted on the English (or any other) Wikipedia.