Modeling Eye Tracking Data with Application to Object Detection

This research focuses on enhancing computer vision algorithms using eye tracking and visual saliency. Recent advances in eye tracking device technology have enabled large scale collection of eye tracking data, without affecting viewer experience. As eye tracking data is biased towards high level image and video semantics, it provides a valuable prior for object detection in images and object extraction in videos. We specifically explore the following problems in the thesis: 1) eye tracking and saliency enhanced object detection, 2) eye tracking assisted object extraction in videos, and 3) role of object co-occurrence and camera focus in visual attention modeling.Since human attention is biased towards faces and text, in the first work we propose an approach to isolate face and text regions in images by analyzing eye tracking data from multiple subjects. Eye tracking data is clustered and region labels are predicted using a Markov random field model. In the second work, we study object extraction in videos using eye tracking prior. We propose an algorithm to extract dominant visual tracks in eye tracking data from multiple subjects by solving a linear assignment problem. Visual tracks localize object search and we propose a novel mixed graph association framework, inferred by binary integer linear programming. In the final work, we address the problem of predicting where people look in images. We specifically explore the importance of scene context in the form of object co-occurrence and camera focus. The proposed model extracts low-, mid- and high-level and scene context features and uses a regression framework to predict visual attention map. In all the above cases, extensive experimental results show that the proposed methods outperform current state-of-the-art

Fusion of Head and Full-Body Detectors for Multi-Object Tracking

In order to track all persons in a scene, the tracking-by-detection paradigm has proven to be a very effective approach. Yet, relying solely on a single detector is also a major limitation, as useful image information might be ignored. Consequently, this work demonstrates how to fuse two detectors into a tracking system. To obtain the trajectories, we propose to formulate tracking as a weighted graph labeling problem, resulting in a binary quadratic program. As such problems are NP-hard, the solution can only be approximated. Based on the Frank-Wolfe algorithm, we present a new solver that is crucial to handle such difficult problems. Evaluation on pedestrian tracking is provided for multiple scenarios, showing superior results over single detector tracking and standard QP-solvers. Finally, our tracker ranks 2nd on the MOT16 benchmark and 1st on the new MOT17 benchmark, outperforming over 90 trackers.Comment: 10 pages, 4 figures; Winner of the MOT17 challenge; CVPRW 201

An Efficient Multiple Object Vision Tracking System using Bipartite Graph Matching

For application domains like 11 vs. 11 robot soccer league, crowd surveillance and air traffic control, vision systems need to be able to identify and maintain information in real time about multiple objects as they move through an environment using video images. In this paper, we reduce the multi-object tracking problem to a bipartite graph matching and present efficient techniques that compute the optimal matching in real time. We demonstrate the robustness of our system on a task of tracking indistinguishable objects. One of the advantages of our tracking system is that it requires a much lower frame rate than standard tracking systems to reliably keep track of multiple objects

Deep Network Flow for Multi-Object Tracking

Data association problems are an important component of many computer vision applications, with multi-object tracking being one of the most prominent examples. A typical approach to data association involves finding a graph matching or network flow that minimizes a sum of pairwise association costs, which are often either hand-crafted or learned as linear functions of fixed features. In this work, we demonstrate that it is possible to learn features for network-flow-based data association via backpropagation, by expressing the optimum of a smoothed network flow problem as a differentiable function of the pairwise association costs. We apply this approach to multi-object tracking with a network flow formulation. Our experiments demonstrate that we are able to successfully learn all cost functions for the association problem in an end-to-end fashion, which outperform hand-crafted costs in all settings. The integration and combination of various sources of inputs becomes easy and the cost functions can be learned entirely from data, alleviating tedious hand-designing of costs.Comment: Accepted to CVPR 201