Learning Multi-view Deep Features for Small Object Retrieval in Surveillance Scenarios

With the explosive growth of surveillance videos, object retrieval has become a significant task for security monitoring. However, visual objects in surveillance videos are usually of small size with complex light conditions, view changes and partial occlusions, which increases the difficulty level of efficiently retrieving objects of interest in a large-scale dataset. Although deep features have achieved promising results on object classification and retrieval and have been verified to contain rich semantic structure property, they lack of adequate color information, which is as crucial as structure information for effective object representation. In this paper, we propose to leverage discriminative Convolutional Neural Network (CNN) to learn deep structure and color feature to form an efficient multi-view object representation. Specifically, we utilize CNN trained on ImageNet to abstract rich semantic structure information. Meanwhile, we propose a CNN model supervised by 11 color names to extract deep color features. Compared with traditional color descriptors, deep color features can capture the common color property across different illumination conditions. Then, the complementary multi-view deep features are encoded into short binary codes by Locality-Sensitive Hash (LSH) and fused to retrieve objects. Retrieval experiments are performed on a dataset of 100k objects extracted from multi-camera surveillance videos. Comparison results with several popular visual descriptors show the effectiveness of the proposed approach.