IEEE Transactions on Circuits and Systems for Video Technology

A vector transform is introduced. The application of the vector transform to image coding is discussed. The development of a vector transform coding technique consists of two parts. One part is to find a vector transform that has the decorrelation and energy-packing properties. The other part is to find a coding algorithm in the vector transform domain. A vector transform, originally developed for... View full abstract»

Adaptive multistage image transform coding is discussed, and an optimal method is introduced for bit allocation. The optimality is in the sense of minimizing the mean square reconstruction error with a given total number of bits and a given number of stages. The statistics of the coefficients in different stages and marginal analysis are used to optimise the division of the total number of bits am... View full abstract»

An optimization technique is presented for the design of multiplierless two-channel linear-phase finite-duration impulse-response (FIR) filter banks. It is shown to yield filter banks with good filtering performance and nearly perfect signal reconstruction. The design employs filters whose coefficients are represented by a canonic signed-digit (CSD) code. When applied to subband image coding this ... View full abstract»

An adaptive image coding technique-two-channel conjugate classified discrete cosine transform/vector quantization (TCCCDCT/VQ)-is proposed to efficiently exploit correlation in large image blocks by taking advantage of the discrete cosine transform and vector quantization. In the transform domain, a classified discrete cosine transform/vector quantization (CDCT/VQ) scheme is proposed and TCCCDCT/V... View full abstract»

The design of 2-D finite impulse response (FIR) digital filters is presented for two-dimensional sampling structure conversion. Both the sampling structure model and the filter characteristics have been chosen to cover a large class of problems related to multidimensional linear processing for video signals. Optimal infinite and finite precision filter design methods are proposed. Experimental ana... View full abstract»

The authors address the problem of adapting the Motion Picture Experts Group (MPEG) quantizer for scenes of different complexity (at bit rates around 1 Mb/s), such that the perceptual quality of the reconstructed video is optimized. Adaptive quantisation techniques conforming to the MPEG syntax can significantly improve the performance of the encoder. The authors concentrate on a one-pass causal s... View full abstract»

The authors focus on some peculiarities of 2-D group delay equalization by means of cascades of 2*2 sections, a 2-D equalization technique that has lately received considerable attention. It appears that the group delay performance obtained by just one or two 2*2 section equalizers cannot be significantly improved by using equalizers with a greater number of sections. As a consequence, this type o... View full abstract»

A nonseparable pyramid method based on a wavelet expansion is developed for image coding. It achieves high compression rates and at the same time allows a very efficient algorithmic implementation. In particular it uses only two additions and a shift (division by 2) for each image pixel during coding or decoding. Because the operations needed are mostly independent of each other and have a high de... View full abstract»

The authors developed a minimax adaptive quantization algorithm that operates in the discrete cosine transform domain conforming to the Moving Picture Experts Group (MPEG) standard. The algorithm is designed to optimize image quality by adapting a quantizer scaling factor to the local characteristics of the video pictures while preserving a constraint on the average output bit rate. The algorithm ... View full abstract»

The authors present an efficient block-matching algorithm called the parallel hierarchical one-dimensional search (PHODS) for motion estimation. Instead of finding the two-dimensional motion vector directly, the PHODS finds two one-dimensional displacements in parallel on the two axes (say x and y) independently within the search area. The major feature of this algorithm is that its search speed f... View full abstract»