Ookaboo “free pictures of everything on earth” have released nearly a million public domain and Creative Commons licensed stock images mapped with precision to concepts, instead of just words.
Because it uses concepts instead of words, Ookaboo is much more accurate than other sources of free stock photos. You’ll find free pictures quickly, because you will only be seeing relevant images.
Unlike some other free pictures sites, images in Ookaboo are public domain or creative commons and can be used freely for blogs, web sites, schoolwork, publications, and other creative projects.
Here for instance is a picture, of the village next to where I live, discovered in Ookaboo associated with the village as a topic:
But there is more.
Ookaboo have released an RDF dump of the metadata behind the images, concept mappings and links to concepts in Freebase and Dbpedia for topics such as places, people and organism classifications.
This is not a one-off exercise, [Ookaboo] intend to use an automated process to make regular releases of the Ookaboo dump in the future.
For the SPARQLy inclined, they also provide an overview of the structure, namespaces, and properties used in the RDF plus a SPARQL cookbook of example queries.
This looks to be a great resource, and when merged with other data sets, potentially capable of adding significant benefit.
I only have one concern, around the licensing. Not of the images themselves, relevant licensing is identified clearly in the data, but the licensing of the RDF dump itself as CC-BY-SA. In the terms of use they indicate:
We require the following attribution:
- Papers, books, and other works that incorporate Ookaboo data or report results from Ookaboo data must cite Ookaboo and Ontology2.
- HTML pages that incorporate images from Ookaboo must include a hyperlink to the page describing the image that is linked with the ookaboo:ookabooPage property.
- Data products derived from Ookaboo must make it possible to maintain the provenance and attribution chain for images. In the case an RDF dump, it is sufficient to provide a connection to Ookaboo identifiers and documentation that refers users to the Ookaboo RDF dump. SPARQL endpoints must contain attribution information, which can be done by importing selected records from the Ookaboo dump.
No problem in principle, but in practice some may find the share-alike elements of the last item a bit difficult to comply with, once you start building applications built on layers of layers of data APIs. Commercial players especially may shy away from using Oookaboo because of the copyleft ramifications. For the data itself, I would have thought CC-BY would have been sufficient.
Maybe Paul Houle, of Ontology2 who are behind Ookaboo, would like to share his reasoning behind this.