In this paper, we propose a new zero-crossing representation in the wavelet transform domain and propose a method of signal reconstruction from it. The proposed zero-crossing representation have additional information that is defined as an inner-product between an original signal and an integral function of the wavelet basis at zero-crossing points. The signal reconstruction method provides a reconstructed signal with SNR of 50 dB. Furthermore, we extend the zero-crossing representation to the 2-dimensional case. The image reconstruction method provides a reconstructed image with SNR of 76 dB.
In a conventional block matching method, prediction efficiency decreases and moreover it becomes difficult to produce a natural predicted image when a block includes an outline of a moving object. It is thought that this problem can be overcome by dividing an image into variable-shape-blocks suitable for its contents From this point of view, this paper proposes a new motion compensation method which partitions the previous image into variable-shape-blocks composed of quadrilateral s so that their boundaries can run parallel with its principal contours. Then texture-mapping using pseudo Affine transformation is carried out in every block to produce a predicted image. Simulation results indicate that this method can provide not only higher prediction efficiency but also more natural predicted images than the conventional block matching method.
This paper presents a motion information representation technique for ultra low bit rate image coding. The proposed technique reduces the amount of motion imformation by extracting representative motion vectors from the original motion vector field. We propose two extracting method. One is "sequential" and uses the skeleton of distance transformation,and the other is "global" and employs Quad-Tree devision. These methods are discussed and the simulation results shows the usefulness of the proposed methods.
Color desktop publishing system has attracted special interest recently. The system has become to be applied to the field of printing and graphic arts industry. From the view point of digital data processing,this paper describes present status and future trends of the relation between DTP system and color electronic prepress system. We think that DTP system will receive wide application in the future. With these electronic system developed, DDCP (Direct Digital Color Proof) system will pay an important role.