Hoang Trinh

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Substantial ambiguities arise in hand tracking due to issues such as small hand size, deformable hand shapes and similar hand appearances. These issues have greatly limited the capability of current multi-target tracking techniques in hand tracking. As an example, state-of-the-art approaches for people tracking handle indentity switching by exploiting the(More)
We demonstrate unsupervised learning of a stereo vision model involving monocular depth cues (shape from texture cues). We formulate a conditional probability model defining the probability of the right image given the left. This conditional model does not model a probability distribution over images. Maximizing conditional liklihood rather than joint(More)
Cashiers in retail stores usually exhibit certain repetitive and periodic activities when processing items. Detecting such activities plays a key role in most retail fraud detection systems. In this paper, we propose a highly efficient, effective and robust vision technique to detect checkout-related primitive activities, based on a hierarchical finite(More)
A variety of approaches using BP and image segmentation have been proposed for the stereo correspondence problem. In this paper, we introduce a novel approach, based on a combination of segmentation and BP. Our method inherits the idea of Multiscale BP, however at each level of the hierarchy, each graph node corresponds to an image segment, which we call(More)
For safety purposes, railroad tracks need to be inspected on a regular basis for physical defects or design non-compliances. Such track defects and non-compliances, if not detected in a timely manner, may eventually lead to grave consequences such as train derailments. In this paper, we present a real-time automatic vision-based rail inspection system, with(More)
A major source of revenue shrink in retail stores is the intentional or unintentional failure of proper checking out of items by the cashier. More recently, a few automated surveillance systems have been developed to monitor cashier lanes and detect non-compliant activities such as fake item checkouts or scans done with the intention of deriving monetary(More)
Humans, as well as many living organisms, are gifted with the power of Bseeing[ and Bunderstanding[ the environment around them using their eyes. The ease with which humans process and understand the visual world is very deceiving and often prompts us to underestimate the effort and methods needed to build practical, effective, and inexpensive computer(More)
We propose a novel approach for enhancing precision in a leading video analytics system that detects cashier fraud in grocery stores for loss prevention. While intelligent video analytics has recently become a promising means of loss prevention for retailers, most of the real-world systems suffer from a large number of false alarms, resulting in a(More)