PEOPLE RETRIEVAL BY MEANS OF COMPOSITE PICTURES: PROBLEM STATE-OF-THE-ART AND TECHNOLOGIES

We discuss the problem of people retrieval by means of composite pictures constructed according to descriptive portrait. An overview of the problem state-of-the-art is provided beginning from the basic concepts and terminology to a modern technology for composite picture creation, real-world scenarios and search results. The development history of systems for forming composite portraits (photo robots and sketches) and the ideas implemented in these systems are provided. The problem of automatic comparison of composite pictures with the original ones is discussed, and the reasons for unattainability of stable retrieval of originals by a composite picture in real-world scenarios are revealed. Requirements to composite pictures databases in addition to the existing benchmark databases of facial images and also methods for implementation of such databases are formulated. Approaches for generation of sketches population from an initial one that increase effectiveness of identikit-based photo image retrieval systems are proposed. The method of similarity index increasing in the couple identikit-photograph based on computation of an average identikit from the created population is provided. It is shown that such composite pictures are more similar to original portraits and their use in the discussed search problem can lead to good results. Thus the created identikits meet the requirements of the truthful scenario as take into account the possibility of incomplete information in descriptions. Results of experiments on CUHK Face Sketch and CUHK Face Sketch FERET databases and also open access identikits and corresponding photos are discussed.