To promote academic researches on earth environment utilizing satellite data, research infrastructure such as satellite data reception, processing, distribution and archival systems should be fully provided. The means to enhance the infrastructure were discussed by a working group and "Satellite Data Center via Network" has been proposed. This concept has three principles; (1) To realize necessary functions by organizing experts distributed all over Japan and connecting them by network, (2) To realize "Satellite Data Center via Network" for GMS and NOAA Satellites, which are widely used for research, and (3) Satellite data set oriented to specific research area should be generated by researchers having definite research purposes in cooperation with researchers in the fields of sensor algorithms and hugh volume data processing. Utilization of the Science Information Network (SINET) has been discussed to realize this concept, and to accelerate this project an experiment "Network Utilization for Wide Area Use of Satellite Image Data" under "Cooperative Experiment on Multimedia Communication" has been introduced. And the roles of the Institute of Industrial Science, University of Tokyo to contribute this project has been described.
This research is on an interactive animation prototype which can be used by many users from different computers, that means a network with one server and many clients. In our research, a complete motion is represented by simple motion characteristics. We establish databases which contain all kinds of human motion characteristics. Using flexible connection and appropriate time control, we are able to recompose a sequential serial motion data. Moreover, an interactive application system is needed among the users with a server from animator. In this research, we also investigate three methods of "connect motion database". We are planing to use the method of connecting motion database under networks with a client-server application system.
This paper presents animation techniques and issues involved in virtual environments where the participants interact with each other through a network. The state of the participant should be recognized at each local site, and broadcast to the other sites. Because information exchange is minimal, animation techniques are applied to convert the incoming low DOF parameters into high DOF joint angles that completely determine the configuration of the agents at each frame. As a case study, a software system VRLOCO is introduced, which has been developed by the author over the last five years. From a simple stream of body center positions, VRLOCO generates realistic curved path human locomotion in real-time. Based on the heading direction and speed, the locomotion automatically switches among five different primitives : walking, running, lateral stepping, backward stepping, and turnaround. The techniques presented here proved robust and faithful : the algorithm is not sensitive to the noise in the data, and the resulting animation conforms well with the original data.
In the field of Virtual Reality, many studies have been reported. Especially, there are many studies on generating virtual creatures on computer systems. In this paper, we propose an algorithm to automatically generate 3D fish models from 2D images which are printed in illustrated books, pictures or handwritings. At first, 2D fish images are captured by means of image scanner. Next, the fish image is separated from background and segmented to several parts such as body, anal fin, dorsal fin, ectoral fin and ventral fin using the proposed method "Active Balloon model". After that, users choose front view model and top view model among six samples, respectively. 3D model is automatically generated from separated body, fins and the above two view models. The number of patches is decreased without any influence on the accuracy of the generated 3D model to reduce the time cost when texture mapping is applied. Finally, we can get any kinds of 3D fish models.
Model-based coding is one of several approaches to very low bit rate image coding and it can be used in many applications such as image creation and virtual reality. However, its analysis and synthesis processes remain difficult, especially in the sense that the resulting synthesized image reveals some degradation in detailed facial components such as furrows around eyes and mouth. To solve the problem, a large number of methods have been proposed and the texture update method is one of them. In this paper, we investigate texture synthesis for model-based coding. In the update process of the proposed texture synthesis algorithm, texture information is stored in a memory and the decoder reuses it. With this method, the transmission bit rate for texture data can be reduced compared with the conventional method updating texture periodically.
This paper proposes a new concept in video called Graphical Video. Graphical Video is a content-based and scalable video representation. A video consists of several elements such as moving images, still images, graphics, characters and charts. All of these elements can be represented graphically except moving images. It is desirable to transform these moving images graphical elements so that they can be treated in the same way as other graphical elements. To achieve this, we propose a new graphical representation of moving images using spatio-temporal clusters, which consist of texture and contours. The texture is described by three-dimensional fractal coefficients, while the contours are described by polygons. We propose a method that gives domain pool location and size as a means to describe cluster texture within or near a region of clusters. Results of an experiment on texture quality confirm that the method provides sufficiently high SNR as compared to that in the original three-dimensional fractal approximation.
In this paper, a method for 3-D surface reconstruction with two real cameras is presented. The method, which combines the extraction of binocular disparity and its interpolation, can be applied to the synthesis of images from virtual viewpoints. The synthesized virtual images are as natural as the real images even when we observe the images as stereoscopic images. The method opens up many applications, such as synthesizing input images for multi-viewpoint 3-D displays, enhancing the depth impression in 2-D images and so on. We also have developed a video-rate stereo machine able to obtain binocular disparity in 1/30 sec with two cameras. We show the performance of the machine.
A new three step hierarchical search algorithm for motion estimation is proposed. The proposed algorithm exploits the motion correlation of spatially neighboring blocks and the motion continuity oftemporally neighboring blocks to alleviate the local minimum problem in the first step of the three step hierarchical search algorithm (3SHS). Simulation results show that the proposed scheme achieves significant improvements in both estimation accuracy and performance reliability compared with the existing fast block matching algorithms including 3SHS, while maintaining almost the same computational complexity as 3SHS. The proposed scheme also possesses the regularity and simplicity of hardware-oriented features.
This paper describes algorithms for the method to generate motions automatically. There are many efforts to generate motions with assistance from computers. But almost of these are methods for generating motions from scratch using computers - generally called "Computer Generated Animation". We propose a method called "Computer Aided Animation" which is a tool to help in animator generating motions. Many motions in cartoonized animation are included with impossible motions for human. Animator makes these motions based on knowledge of experiental techniques. The method in this paper works like a filter in the field of image processing. We call this method "Motion Filter". Motion Filter accepts captured motions from motion capture system and translate these motions to emphasized - cartoonized - motions.
Multimedia boom has happened worldwide these days. In multimedia, we use several kinds of media such as character, figure, voice, music, still images, moving picture etc.. Then I think image including moving picture is the most effective and important media for human being. Creating digital images using a computer has the following two main approaches, depending on how the computer is used. 1. CG Technology. Created images, produced through computer graphics. 2. Digital Image Processing. Images processed through digital image processing technologies. Approach (1) is very popular as Computer Graphics. Two-dimensional and three-dimensional computer graphics techniques are used over wide applications today. On the other hand, Approach (2), which uses digital image processing technology, has been attracting attention lately, in the field of movies and television. In this report, I will introduce these approaches of CG and digital image processing, and show some application fields such as current movies.
The Internet offers multicasting applications for interactive multimedia applications. MBone and CU-SeeMe are notable systems, and are introduced here as examples of the multicasting systems on the Internet. They are available globally now, and numerous applications are appearing on these systems and others.
In this paper, an efficient contour coding algorithm incorporating polygonal approximation and discrete sine transform is introduced. Contour information is inevitable in content based coding, and polygonal approximation method is widely used to compress the contour information. However polygonal approximation method is not suitable when fine contour is needed. We show that the error signal of polygonal approximation can be efficiently represented using DST, that is, the contour information can be represented accurately with polygons and DST coefficients. With this contour coding scheme, the required bits to represent a contour can be reduced by about 40-50% with virtually no degradation compared to the existing chain coding method.
We have developed an MPEG2 realtime codec system and ATM interface, and evaluated the performance and characteristics of the audio-visual communication in terms of Interoperability Specification of The ATM Forum, ITU-T H.310 draft recommendation ^<> and the reference points of DAVIC specification through the experiments using the experimental public ATM network.
We propose a novel algorithm for fractal video sequence coding, based on the circular prediction mapping (CPM), in which each range block is approximated by a domain block in the circularly previous frame. In our approach, the sise of the domain block is set to be same as that of the range block for exploiting the high temporal correlation between the adjacent frames, while most other fractal coders use the domain block larger than the range block. Therefore the domain-range mapping in the CPM is similar to the block matching algorithm in the motion compensation techniques, and the advantages of this similarity are discussed. Also we show that the CPM can be combined with non-contractive inter-frame mapping (NCIM), improving the performance of the fractal sequence coder further. The computer simulation results on real image sequences demonstrate that the proposed algorithm provides very promising performance at low bit-rate, ranging from 40 Kbps to 250 Kbps.