IEEE Transactions on Circuits and Systems for Video Technology

This paper presents several error resilient video coding methods based on redundant pictures. We combine redundant picture coding with reference picture selection and reference picture list reordering to prevent error propagation in motion compensated video coding. A hierarchical redundant picture allocation method is employed to make a tradeoff between error resilience and coding efficiency. For ... View full abstract»

In this paper, a simultaneous MAP-based video denoising and rate-distortion optimized video encoding algorithm is proposed. We begin with formulating the denoising problem as a maximum <i>a</i> <i>posteriori</i> (MAP) estimate problem. Then, according to the Bayes rule, we show that the MAP estimate is determined by two terms: noise conditional density model and <i>pr... View full abstract»

In this paper, we present a patch-based variational Bayesian framework for video processing and demonstrate its potential in denoising, inpainting and deinterlacing. Unlike previous methods based on explicit motion estimation, we propose to embed motion-related information into the relationship among video patches and develop a nonlocal sparsity-based prior for typical video sequences. Specificall... View full abstract»

This paper proposes a hardware architecture for object detection based on an AdaBoost learning algorithm with Haar-like features as weak classifiers. We analyze and discuss the parallelism in this detection algorithm and propose a partially parallel execution model suitable for hardware implementation. This parallel execution model exploits the cascade structure of classifiers, in which classifier... View full abstract»

In this paper, a combined kernel architecture for efficiently decoding the residual data in the H.264/AVC baseline decoder is proposed. The kernel architecture in the H.264/AVC decoder consists of context-based adaptive variable length code (CAVLC) decoder, inverse quantization (IQ), and inverse transforms (IT) units. Since the decoding speeds of these kernel units vary with data, traditional meth... View full abstract»

This paper describes a unified framework for object mining system for videos, which combines shot segmentation, clustering, retrieval and object mining using a single set of detected local invariant regions. The local invariant regions are tracked throughout a shot and stable tracks are extracted. The conventional key frame method is replaced with these stable tracks of local regions to characteri... View full abstract»

This paper presents an end-to-end system for moving object verification in airborne video sequences. Using a sample selection module, the system first selects frames from a short sequence and stores them in an exemplar database. To handle appearance change due to potentially large aspect angle variations, a homography-based view synthesis method is then used to generate a novel view of each image ... View full abstract»

This paper introduces a head pose estimation system that automatically localizes the nose-tips of the faces and estimates head poses in images simultaneously. In the training stage, the nose-tips of the faces are first manually labeled. The appearance variations caused by head pose changes are then characterized by a tensorposes model. Given an image with unknown head pose and nose-tip location, t... View full abstract»

In H.264/AVC video encoding, zero quantized discrete cosine transform (DCT) coefficients are quite common in low bit-rate video application. The computations of DCT and quantization can be remarkably reduced if zero quantized DCT coefficients are detected prior to DCT and quantization. Many methods have been applied to early detect most zero quantized DCT coefficients. But the detection ratios of ... View full abstract»

Pattern-based block motion estimation (PBME) is one of the most widely adopted compression tools in the contemporary video coding systems. However, despite that many researches have studied PBME, few have yet attempted to construct an analytical model that can explain the underneath principle and mechanism of various PBME algorithms. In this paper, we propose a statistical PBME model that consists... View full abstract»

Occlusion reasoning is one of the most challenging issues in visual surveillance. In this letter, we propose a new approach for reasoning about occlusions between multiple people. In our approach, occlusion relationships between people are explicitly defined and deduction of the occlusion relationships is integrated into the whole tracking framework. The prior knowledge is supplied by a set of mod... View full abstract»

In this paper, we study the rate-distortion (RD) optimization of the H.264 main profile encoding. Specifically, a soft decision quantization (SDQ) algorithm is developed based on the context adaptive binary arithmetic coding (CABAC) method in the H.264 main profile. Given motion prediction and quantization step sizes, the proposed SDQ algorithm is proved to achieve near-optimal SDQ for residual co... View full abstract»

The latest video coding standard H.264/AVC significantly outperforms previous standards in terms of coding efficiency. H.264/AVC adopts variable block sizes ranging from 4 times 4 to 16 times 16 in inter frame coding, and achieves significant gain in coding efficiency compared to coding a macroblock (MB) using regular block size. However, this new feature causes extremely high computation complexi... View full abstract»

In this letter, we introduce a novel approach for lip activity detection and speaker detection, using solely visual information. The main idea in this work is to apply signal detection algorithms to a simple and easily extracted feature from the mouth region. We argue that the increased average value and standard deviation of the number of pixels with low intensities that the mouth region of a spe... View full abstract»