This preserves the robustness of each feature, while increasing the capacity of the histogram space. We have used a large image collection of almost 250,000 images. More specifically, these are image pairs where the same scene is shown from two rather different views. On this database, our methods perform significantly better than color histograms. Some specific examples are given in figures 3 and 4, using both color correlograms and joint histograms.
Lower numbers indicate better performance.
Lower numbers indicate better performance. We believe that a retrieval performance measure should be independent of the number of images. Typically a user is willing to browse a certain number of the retrieval results by hand, similar to text-based search on the web. This number is unlikely to change as the database fluctates in size, as it is really a measure of human patience. We call this number the scope of the user.