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This article relates to interactive command coding with active participation by the user in the coding process through his interactive operations, and structuralization of a moving image according to its substance. This coding process enables a low rate transmission with the preferential transmission of the substance of the original image, which is performed by using the user's interactive operations for extracting characteristics of objects relating to their shapes, texture, and motions, and by appropriately assigning a detailed description-based or simplified description-based technique, depending on the substance of the original image. In addition, it enables easy browsing for capturing outlines on the decoding side, and easy application even to nonlinear image editing, by modifying the motion-related parameters and also modifying the feature description technique to another technique. Concrete examples including test examples are given to explain this approach. © 1999 Scripta Technica, Syst Comp Jpn, 30(13): 73–83, 1999 [ABSTRACT FROM AUTHOR]

This paper proposes the adaptive discrete cosine transform coding with vector quantization (adaptive DCT-VQ), as a highly efficient coding for the picture signal. In the proposed method, the vector quantization is performed by applying the discrete cosine transform to the picture subblock and partitioning the transformed domain into several vectors. By regarding the transformed domain as more than one vector, the complexity in the coding is reduced. Each vector quantizer is designed according to the standard probability distribution of the cosine transform coefficient, and the universality of the vector quantizer is realized. The mode-selecting type adaptive control is introduced, to effect the adaptive control of the coding parameters according to the local property of the picture. To cope with the large bit allocation resulting from the adaptive control, each vector quantizer has two-stage structure thereby reducing the coding complexity. As a result of the performance evaluation by simulation, it was verified that the proposed coding method has a higher performance than the conventional adaptive cosine transform coding and has much less complexity than the vector quantization in the original space domain. [ABSTRACT FROM AUTHOR]

To realize fast search at vector quantization applied to high-efficiency coding of signals, we propose a partial distance algorithm and a nearest-neighbor search algorithm, both in the orthogonal transform domain. These algorithms provide efficient search for signals such as, for example, picture signals which have a concentration in the transform domain power distribution. Further, we propose a nearest-neighbor search algorithm in orthogonal transform domain with component selection which is effective also for memoryless random information sources with Gaussian distribution. The proposed algorithm is applied to vector quantizers of picture signals, separating-mean-normalized vector quantizers, and vector quantizers of memoryless Gaussian sources and its efficiency is demonstrated for these cases. Particularly, in the case of vector quantizers of picture signals, it is shown that the proposed method requires fewer multiplications to determine the optimum reconstructing vector than the conventional tree search algorithm. [ABSTRACT FROM AUTHOR]

A gain/shape vector quantizer for orthogonal transform domain has been designed based on a previous paper [11] on a gain/shape vector quantizer for a spherically symmetric random source. Such a design method is used in the design of a discrete cosine transform encoder with gain/shape vector quantizer. This encoder is similar to that described in [7] except in the following: (i) it has a gain/shape codebook; and (ii) its normalized coefficients of discrete cosine transform are modeled as having spherically symmetric distribution. The S/N rendition of this encoder is 1.0 - 2.5 dB better than that of the DCT coding scheme with Max-type scalar quantizer at the same bit rate. Furthermore, in spite of its similarity to the conventional discrete cosine transform coding scheme with vector quantizer [7], the encoder introduced in this paper delivers higher S/N using the same number of multiplications for the quantization of normalized coefficients, and/or the same amount of memory for the codebook. [ABSTRACT FROM AUTHOR]

In a picture data base the picture quality required depends on the actual application of the picture signal. Therefore efficient reversible coding systems are needed. On the other hand, users demand easy searching of the required pictures. Considering the above facts, two kinds of information preserving transmission systems-System 1 and System 2-are proposed for picture data base treating 8-bit PCM picture signals. In these systems, first, reference picture signal for user's reference are transmitted. Next, a supplementary transmission is performed. In System 1 a degenerate differential signal between PCM picture signal and reference picture signal is encoded and transmitted. In system 2, PCM picture signal is reversibly encoded and transmitted directly. In this paper, four kinds of coding systems are considered as coding system for reference pictures. The best performance has been achieved by discrete cosine transform pictures. The best performance has been achieved by discrete cosine transform coding. In addition, this paper presents a method for determining the better system in performance of supplementary transmission of the two systems on the basis of signal-to-noise ratio of the reference picture. Finally, the realization of a transmission systems is shown which combines the advantages of both Systems 1 and 2 by choosing the better system on the basis of coding performance at each reference picture. [ABSTRACT FROM AUTHOR]