IEEE Transactions on Circuits and Systems for Video Technology

We present a human face location technique based on contour extraction within the framework of a wavelet-based video compression scheme for videoconferencing applications. In addition to an adaptive quantization in which spatial constraints are enforced to preserve perceptually important information at low bit rates, semantic information of the human face is incorporated to design a hybrid compres... View full abstract»

A new technique of adaptively classifying the scene content of an image block has been developed in the proposed perceptual coder. It measures the texture masking energy of an image block and classifies it into one of four perceptual classes: flat, edge, texture, and fine-texture. Each class has an associated factor to adapt the quantizer with the aim of achieving constant quality across an image.... View full abstract»

A block-based gradient descent search (BBGDS) algorithm is proposed in this paper to perform block motion estimation in video coding. The BBGDS evaluates the values of a given objective function starting from a small centralized checking block. The minimum within the checking block is found, and the gradient descent direction where the minimum is expected to lie is used to determine the search dir... View full abstract»

A scalable implementation scheme for multirate finite impulse response (FIR) filters is presented in this paper. The implementation scheme can reduce the time and area cost of a multirate FIR filter simultaneously. According to the throughput requirement, the proposed scheme achieves a minimum-area design with specified speed. Furthermore, by employing the scalable implementation scheme, we also p... View full abstract»

The goal of this paper is to study the application of two-dimensional (2-D) finite-precision infinite impulse response (IIR) filters to enhanced National Television System Committee (NTSC) coding. It is well-known that suitable twoor three-dimensional (3-D) digital filtering greatly improves the quality of NTSC pictures by suppressing the interference between the luminance Y and the chrominances I... View full abstract»

An efficient video coding scheme is presented as an extension of the MPEG-2 standard to accommodate the transmission of multiple viewpoint sequences on bandwidth-limited channels. With the goal of compression and speed, the proposed approach incorporates a variety of existing computer graphics tools and techniques. Construction of each viewpoint image is predicted using a combination of perspectiv... View full abstract»

This paper presents a new systolic architecture that can be used to realize the full-search vector quantization (VQ) encoder for high-speed applications. The architecture possesses the features of regularity and modularity, and is thus very suitable for VLSI implementation. For a codebook of size N and dimension k, the VQ encoder has an area complexity of O(N), a time complexity of O(k), and I/O b... View full abstract»

We note that the arrangement of the rows or the block wavelet transform (BWT) matrix as given by Cetin, Gerek and Ulukus (see ibid. vol.3, no.6, p.433, 1993) is not in an increasing order of frequency as implied by the equations and figures in the same paper. The rows of the matrix are rearranged to follow an increasing order of frequency View full abstract»

A method of coding super high definition (SHD) still images based on vector quantization of wavelet coefficients is proposed. A compression scheme for SHD images should achieve data compression without any visible picture quality deterioration. We demonstrate that the proposed method meets this requirement. In this coding technique, each vector of wavelet coefficients is coded by a series of vecto... View full abstract»

Scalability refers to the ability to modify the resolution and/or bit rate associated with an already compressed data source in order to satisfy requirements which could not be foreseen at the time of compression. A number of researchers have already demonstrated the feasibility of efficient scalable image and video compression. The principle focus of this paper is to describe data structures for ... View full abstract»