Browsing CBCL Memos (1993 - 2004) by Title
Now showing items 82-101 of 123
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People Recognition in Image Sequences by Supervised Learning
(2000-06-01)We describe a system that learns from examples to recognize people in images taken indoors. Images of people are represented by color-based and shape-based features. Recognition is carried out through combinations of Support ... -
Perceiving Illumination Inconsistencies in Scenes
(2001-11-05)The human visual system is adept at detecting and encoding statistical regularities in its spatio-temporal environment. Here we report an unexpected failure of this ability in the context of perceiving inconsistencies in ... -
Perceptual Evaluation of Video-Realistic Speech
(2003-02-28)abstract With many visual speech animation techniques now available, there is a clear need for systematic perceptual evaluation schemes. We describe here our scheme and its application to a new video-realistic ... -
Perceptually-based Comparison of Image Similarity Metrics
(2001-07-01)The image comparison operation ??sessing how well one image matches another ??rms a critical component of many image analysis systems and models of human visual processing. Two norms used commonly for this purpose are L1 ... -
Policy Improvement for POMDPs Using Normalized Importance Sampling
(2001-03-20)We present a new method for estimating the expected return of a POMDP from experience. The estimator does not assume any knowle ge of the POMDP and allows the experience to be gathered with an arbitrary set of policies. ... -
Pre-Attentive Segmentation in the Primary Visual Cortex
(1998-06-30)Stimuli outside classical receptive fields have been shown to exert significant influence over the activities of neurons in primary visual cortexWe propose that contextual influences are used for pre-attentive visual ... -
Priors Stabilizers and Basis Functions: From Regularization to Radial, Tensor and Additive Splines
(1993-06-01)We had previously shown that regularization principles lead to approximation schemes, as Radial Basis Functions, which are equivalent to networks with one layer of hidden units, called Regularization Networks. In this ... -
Probabilistic Independence Networks for Hidden Markov Probability Models
(1996-03-13)Graphical techniques for modeling the dependencies of randomvariables have been explored in a variety of different areas includingstatistics, statistical physics, artificial intelligence, speech recognition, image ... -
Properties of Support Vector Machines
(1997-08-01)Support Vector Machines (SVMs) perform pattern recognition between two point classes by finding a decision surface determined by certain points of the training set, termed Support Vectors (SV). This surface, which in some ... -
The Quadric Reference Surface: Theory and Applications
(1994-06-01)The conceptual component of this work is about "reference surfaces'' which are the dual of reference frames often used for shape representation purposes. The theoretical component of this work involves the question ... -
Reciprocal Interactions Between Motion and Form Perception
(1995-04-21)The processes underlying the perceptual analysis of visual form are believed to have minimal interaction with those subserving the perception of visual motion (Livingstone and Hubel, 1987; Victor and Conte, 1990). ... -
Recognizing Indoor Scenes
(2001-07-25)We propose a scheme for indoor place identification based on the recognition of global scene views. Scene views are encoded using a holistic representation that provides low-resolution spatial and spectral information. The ... -
Relative Contributions of Internal and External Features to Face Recognition
(2003-03-01)The central challenge in face recognition lies in understanding the role different facial features play in our judgments of identity. Notable in this regard are the relative contributions of the internal (eyes, nose and ... -
Risk Bounds for Mixture Density Estimation
(2004-01-27)In this paper we focus on the problem of estimating a bounded density using a finite combination of densities from a given class. We consider the Maximum Likelihood Procedure (MLE) and the greedy procedure described by ... -
Role of color in face recognition
(2001-12-13)One of the key challenges in face perception lies in determining the contribution of different cues to face identification. In this study, we focus on the role of color cues. Although color appears to be a salient attribute ... -
Role of Low-level Mechanisms in Brightness Perception
(2001-08-01)Brightness judgments are a key part of the primate brain's visual analysis of the environment. There is general consensus that the perceived brightness of an image region is based not only on its actual luminance, but also ... -
Rotation Invariant Object Recognition from One Training Example
(2004-04-27)Local descriptors are increasingly used for the task of object recognition because of their perceived robustness with respect to occlusions and to global geometrical deformations. Such a descriptor--based on a set of ... -
Rotation Invariant Real-time Face Detection and Recognition System
(2001-05-31)In this report, a face recognition system that is capable of detecting and recognizing frontal and rotated faces was developed. Two face recognition methods focusing on the aspect of pose invariance are presented and ... -
Selecting Relevant Genes with a Spectral Approach
(2004-01-27)Array technologies have made it possible to record simultaneously the expression pattern of thousands of genes. A fundamental problem in the analysis of gene expression data is the identification of highly relevant genes ... -
Sequential Optimal Recovery: A Paradigm for Active Learning
(1995-05-12)In most classical frameworks for learning from examples, it is assumed that examples are randomly drawn and presented to the learner. In this paper, we consider the possibility of a more active learner who is allowed ...
