How do I get link to an image on wikipedia from the infobox?

Question

I'm parsing wikipedia infoboxes and I noticed that some infoboxes have image fields - these fields hold names of image files stashed on wikipedia somewhere. However they just contain the name of the file as is as opposed to the actual link.

I checked the links of the images on real live infoboxes and the links do not seem to be from one source but the sources vary. How can I hyperlink to an image on wikipedia considering I only have the name of the image from an infobox entry.

Answer 1

Have you tried http://en.wikipedia.org/wiki/File:filename.jpg ? Even if the files are located on Wikimedia Commons, the above URL should still work.

Edit: Are you trying to hotlink the image? If so, Wikipedia prohibits hotlinking. http://commons.wikimedia.org/wiki/Commons:Reusing_content_outside_Wikimedia#Hotlinking

Update 10-Jan-2019: Hotlinking is now permitted:

Hotlinking or InstantCommons: It is possible to use files directly on Commons within another website, by setting up a MediaWiki wiki with InstantCommons, ...

Answer 2

According to What are the strangely named components in Wikipedia file paths, you need to run md5 to find out url. Now wikipedia allows hotlinking, so:

If you have utf-8 encoded $name, you need to do the following:

$filename = replace($name, ' ', '_');
$digest = md5($filename);
$folder = $digest[0] . '/' . $digest[0] . $digest[1] . '/' .  urlencode($filename);
$url = 'http://upload.wikimedia.org/wikipedia/commons/' . $folder;

The same can be used for thumbnails.

Answer 3

Here is a JavaScript implementation of a working PHP answer (credits to Yuri Baburov):

var name = "filename.jpg";
var filename = name.replace(/ /g, "_"); 
var digest = md5(filename);
var folder = digest[0] + '/' + digest[0] + digest[1] + '/' + encodeURIComponent(filename);
var url = 'http://upload.wikimedia.org/wikipedia/commons/' + folder;

Note that you must include external md5() function (https://github.com/blueimp/JavaScript-MD5); it is not native to JS.

Answer 4

There is now a simpler way to hotlink the files on Wikipedia using the Special:FilePath page. Hence, if you want to link the file Example.jpg on English Wikipedia, you can use https://en.wikipedia.org/wiki/Special:FilePath/Example.jpg.

Similar links should work for other Wikimedia Foundation sites (e. g. Wikimedia Commons).

Details and recommendations regarding hotlinking can be found on Wikimedia's Commons:Reusing_content_outside_Wikimedia.

Answer 5

I noticed that the URL prefix should be:

http://upload.wikimedia.org/wikipedia/en/thumb/

Moreover the folder must contain the repeated name of the file with a size specified as prefix:

http://upload.wikimedia.org/wikipedia/en/thumb/d/dd/Ruins-imperial-complex-milan-.jpg/220px-Ruins-imperial-complex-milan-.jpg

$filename = replace($name, ' ', '_');
$digest = md5($filename);
$urlencfile =  urlencode($filename)
$imgwidth = 220
$folder = $digest[0] . '/' . $digest[0] . $digest[1] . '/' . $urlencfile . '/' . $imgwidth . 'px-' . $urlencfile;
$url = 'http://upload.wikimedia.org/wikipedia/en/thumb/' . $folder;