The CoPhIR (Content-based Photo Image Retrieval) Test-Collection has been developed to make significant tests on the scalability of the SAPIR project infrastructure (SAPIR: Search In Audio Visual Content Using Peer-to-peer IR) for similarity search.

CoPhIR is the result of a joint effort of NEMIS Lab and HPC Lab of ISTI-CNR in Pisa, Italy. We have extracted metadata from the Flickr archive, using the EGEE European GRID, through the DILIGENT project. For each image, the standard MPEG-7 image feature have been extracted. Each entry of the test-bed contains: o The link to the corresponding entry into Flickr Web site o The photo image thumbnail o An XML structure with the Flickr user information in the corresponding Flickr entry: title, location, GPS, tags, comments, etc. o An XML structure with 5 extracted standard MPEG-7 image features: Scalable Colour, Colour Structure, Colour Layout, Edge Histogram, Homogeneous Texture.

The data collected consist of 106 million processed images.