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Within the past decade, significant effort has occurred in developing methods of facial expression analysis. Because most investigators have used relatively limited data sets, the generalizability of these various methods remains unknown. We describe the problem space for facial expression analysis, which includes level of description, transitions among(More)
Most automatic expression analysis systems attempt to recognize a small set of prototypic expressions, such as happiness, anger, surprise, and fear. Such prototypic expressions, however, occur rather infrequently. Human emotions and intentions are more often communicated by changes in one or a few discrete facial features. In this paper, we develop an(More)
  • Ying-li Tian
  • 2004 Conference on Computer Vision and Pattern…
  • 2004
Most automatic facial expression analysis (AFEA) systems attempt to recognize facial expressions from data collected in a highly controlled environment with very high resolution frontal faces ( face regions greater than 200 x 200 pixels). However, in real environments, the face image is often in lower resolution and with head motion. It is unclear that the(More)
Objects in the world exhibit complex interactions. When captured in a video sequence, some interactions manifest themselves as occlusions. A visual tracking system must be able to track objects which are partially or even fully occluded. In this paper we present a method of tracking objects through occlusions using appearance models. These models are used(More)
We present a new method to robustly and efficiently analyze foreground when we detect background for a fixed camera view by using mixture of Gaussians models and multiple cues. The background is modeled by three Gaussian mixtures as in the work of Stauffer and Grimson (1999). Then the intensity and texture information are integrated to remove shadows and to(More)
Tracking-based approaches for abandoned object detection often become unreliable in complex surveillance videos due to occlusions, lighting changes, and other factors. We present a new framework to robustly and efficiently detect abandoned and removed objects based on background subtraction and foreground analysis with complement of tracking to reduce false(More)
For many practical applications, it is sufficient to estimate coarse head to infer gaze direction. Indeed for any application in which the camera is situated unobtrusively in an overhead corner, the only possible inference is coarse pose because of the limitations of the quality and resolution of the incoming data. However, the vast majority of research in(More)
Closed-circuit television cameras used today for surveillance sometimes enable privacy intrusion. The authors' privacy console manages operator access to different versions of video-derived data according to access-control lists. Additionally, their PrivacyCam is a smart camera that produces a video stream with privacy-intrusive information already removed.
Previous work suggests that Gabor-wavelet-based methods can achieve high sensitivity and specificity for emotionspecified expressions (e.g., happy, sad) and single action units (AUs) of the Facial Action Coding System (FACS). This paper evaluates a Gabor-wavelet-based method to recognize AUs in image sequences of increasing complexity. A recognition rate of(More)
Effectively evaluating the performance of moving object detection and tracking algorithms is an important step towards attaining robust digital video surveillance systems with sufficient accuracy for practical applications. As systems become more complex and achieve greater robustness, the ability to quantitatively assess performance is needed in order to(More)