PKUBench: A context rich mobile visual search benchmark

While there are ever growing focuses on mobile visual search in recent years, a comprehensive benchmark database with rich context information (such as GPS) for fair evaluation among different strategies is still missing. This paper introduces a PKUBench benchmark for the quantitative evaluations of mobile visual search with the support of GPS. It contains 13,179 images organized into 198 distinct landmark locations within the Peking University campus. Each location is captured with multiple shot sizes and viewing angles, using both digital cameras and phone cameras, each photo being tagged with rich contextual information in the mobile scenario. Moreover, this benchmark studies typical quality degeneration scenarios in mobile photographing, including variable resolutions, blurring, lighting changes, occlusions, as well as various viewing angles. Together with this benchmark, we provide the bag-of-visual-words search baselines involving contextual information refinement. Finally, distractor images are further introduced to evaluate the robustness of visual search methods in this database.