How to get image URL property from Wikidata item by API?

Issue

I've made an android app that uses the JSON Google image search API to provide images but I have noticed that Google have stopped supporting it. I have also discovered that Wikidata sometimes provides a image property on some items, however I can't seem to get the URL location of the image using the Wikidata API.

Is there any way to get the image URL property from items in Wikidata?

Solution

If some Wikidata item (with ID: Qxxx) has image (P18) property, you can access it by MediaWiki API:

https://www.wikidata.org/w/api.php?action=wbgetclaims&property=P18&entity=Qxxx

The response will include:

"claims": {
        "P18": [{ "mainsnak": { "datavalue": { "value": "img_name.ext" }, "hash": ... }}]
}

where img_name.ext is the name of the image you are looking for.

The final image URL will be: https://upload.wikimedia.org/wikipedia/commons/a/ab/img_name.ext, where a and b are the first and the second chars of MD5 hashsum of the img_name.ext (with all whitespaces replaced by _).

Example: For item jaguar (Q35694) the API will returns image name "Junior-Jaguar-Belize-Zoo.jpg", which has MD5 hashsum("Junior-Jaguar-Belize-Zoo.jpg") = 213b31ec141dafebe457e49bcd7f9329, so a=2 and b=1, or the final image URL will be: https://upload.wikimedia.org/wikipedia/commons/2/21/Junior-Jaguar-Belize-Zoo.jpg

Note: The MD5 hashsum is for the name of the image file, not the P18[0].mainsnak.hash property included in the JSON body.

Answered By - Termininja