Multi-Person Tracking Based on Faster R-CNN and Deep Appearance Features

Mostly computer vision problems related to crowd analytics are highly dependent upon multi-object tracking (MOT) systems. There are two major steps involved in the design of MOT system: object detection and association. In the first step, desired objects are detected in every frame of video stream. Detection quality directly influences the performance of tracking. The second step involves the correspondence of detected objects in current frame with the previous to obtain their trajectories. High accuracy in object detection system results in less number of missing detection and finally produces less fragmented tracks. Better object association increases the affinity between objects in different frames. This paper presents a novel algorithm for improved object detection followed by enhanced object tracking. Object detection accuracy has been increased by employing deep learning-based Faster region convolutional neural network (Faster R-CNN) algorithm. Object association is carried out by using appearance and improved motion features. Evaluation results show that we have enhanced the performance of current state-of-the-art work by reducing identity switches and fragmentation

Methods to Robust Ranking of Object Trackers and to Tracker Drift Correction

This thesis explores two topics in video object tracking: (1) performance evaluation of tracking techniques, and (2) tracker drift detection and correction. Tracking performance evaluation consists into comparing a set of trackers' performance measures and ranking these trackers based on those measures. This is often done by computing performance averages over a video sequence and then over the entire test video dataset, consequently resulting in an important loss of statistical information of performance between frames of a video sequence and between the video sequences themselves. This work proposes two methods to evaluate trackers with respect to each other. The first method applies the median absolute deviation (MAD) to effectively analyze the similarities between trackers and iteratively ranks them into groups of similar performances. The second method gains inspiration from the use of robust error norms in anisotropic diffusion for image denoising to perform grouping and ranking of trackers. A total of 20 trackers are scored and ranked across four different benchmarks, and experimental results show that using our scoring evaluation is more robust than using the average over averages. In the second topic, we explore methods to the detection and correction of tracker drift. Drift detection refers to methods that detect if a tracker is about to drift or has drifted away while following a target object. Drift detection triggers a drift correction mechanism which updates the tracker's rectangular output bounding box. Most drift detection and correction algorithms are called while the target model is updating and are, thus, tracker-dependent. This work proposes a tracker-independent drift detection and correction method. For drift detection, we use a combination of saliency and objectness features to evaluate the likelihood an object exists inside a tracker's output. Once drift is detected, we run a region proposal network to reinitialize the bounding box output around the target object. Our implementation applied on two state-of-the-art trackers show that our method improves overall tracker performance measures when tested on three benchmarks

Small Object Detection and Tracking: A Comprehensive Review

Object detection and tracking are vital in computer vision and visual surveillance, allowing for the detection, recognition, and subsequent tracking of objects within images or video sequences. These tasks underpin surveillance systems, facilitating automatic video annotation, identification of significant events, and detection of abnormal activities. However, detecting and tracking small objects introduce significant challenges within computer vision due to their subtle appearance and limited distinguishing features, which results in a scarcity of crucial information. This deficit complicates the tracking process, often leading to diminished efficiency and accuracy. To shed light on the intricacies of small object detection and tracking, we undertook a comprehensive review of the existing methods in this area, categorizing them from various perspectives. We also presented an overview of available datasets specifically curated for small object detection and tracking, aiming to inform and benefit future research in this domain. We further delineated the most widely used evaluation metrics for assessing the performance of small object detection and tracking techniques. Finally, we examined the present challenges within this field and discussed prospective future trends. By tackling these issues and leveraging upcoming trends, we aim to push forward the boundaries in small object detection and tracking, thereby augmenting the functionality of surveillance systems and broadening their real-world applicability