摘要:

AbstractThis paper proposes a hardware‐oriented method of computation for determining the shape descriptors of individual figures and which processes in real‐time at the video rate the input signal obtained by raster scanning. The method consists in the following techniques: (1) The connectivity of the figure on a raster is represented by a sequence of attribute symbols; (2) the attribute symbol sequence of an arbitrary raster is generated automatically; (3) the descriptors of the figure are calculated cumulatively by referring to the attribute symbol sequence. By the proposed method, an accurate and complete representation is obtained for any complex figure with intricate placeme

ISSN:0882-1666    

DOI:10.1002/scj.4690211001

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe protocol on the OSI basic reference model is standardized as a hierarchical model composed of seven layers. Protocols of some layers are applied link‐by‐link and protocols of other layers are applied end‐to‐end. The transmission timing of the protocol data unit of each layer depends on the network configuration as well as the protocol parameters. Consequently, there is a possibility that the throughput of the network is deteriorated unless the protocol parameters of each layer are determined adequately according to the network configuration. This paper considers the network containing the transport layer, network layer and data link layer of OSI protocol, and the performance is evaluated from the viewpoint of transmission efficiency, which is a measure in evaluating the network throughput. The relation between the protocol parameters and the throughput is derived. As the protocol parameters, the transmission speed, transmission delay, data unit length, window size, number of intermediate nodes, bit error rate and protocol processing time are considered. The protocol parameters can be determined based on the presented

ISSN:0882-1666    

DOI:10.1002/scj.4690211002

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe short‐term Fourier transform analysis‐synthesis technique is promising as a means to obtain high‐quality synthetic speech, since the original speech can be reconstructed from the parameters of analysis. This paper proposes a speech modification method using this synthesis system, especially the pitch frequency modification. Among various methods of the short‐term Fourier spectrum synthesis, the proposed method employs the minimization of squared error between the spectrum of the reconstructed speech and that of the target speech. The proposed method features the following two points: [1] In the pitch frequency modification, only the parameters exclusively related to the pitch frequency are modified; [2]the phase spectrum is not manipulated directly but is estimated by the speech reconstruction algorithm. As a result of evaluation of the proposed method by a hearing test, it was verified that a high‐quality modified speech is obtained for both the uniform pitch modification over the whole word and the nonuniform pitch modification to change the accent position of

ISSN:0882-1666    

DOI:10.1002/scj.4690211003

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA multiprocessor system with bus connections has a throughput which may be reduced significantly due to the bus conflict. One approach to ease this conflict is to group processors into a few clusters. This paper presents a clustered multiprocessor prototype called “MUGEN” and the systems software implemented. Its performance also is disusssed. As for the systems software, ext‐C and para‐C languages are introduced that are developed to express parallelism explicitly. Also, the par‐C preprocessor (P3C) that translates a standard C program into a parallel program written in para‐C is introduced. Finally, the Livermore loop results are presented to measure the

ISSN:0882-1666    

DOI:10.1002/scj.4690211004

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe authors have proposed several pointing methods (a combination of pointing device and the controlling software), aiming at the improvement of the user interface using the pointing device. Experiments have been made to evaluate the effect of those techniques on the pointing efficiency, such as the time for pointing, the work area and the ratio of unsuccessful pointing. This paper assumes the high‐resolution display, which will be developed in the future, together with the progress in the computer performance. The pointing by a mouse is considered, and the effect of the screen resolution on the pointing efficiency is examined. As a result, it is seen in the case of the high‐resolution display that the nonlinear technique, where the cursor moves as a nonlinear function of the speed of the mouse, is useful in reducing the working area on the desk and the time required for point

ISSN:0882-1666    

DOI:10.1002/scj.4690211005

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA multiwindow system is one in which several rectangular regions called windows are defined on the screen of CRT or other display devices, and the user can handle each of the windows as if they were separate display devices. The features of such a system are that it has the virtual function and multiwindow image synthesis function. One of the important requirements is to reduce the overhead due to those added functions.

ISSN:0882-1666    

DOI:10.1002/scj.4690211006

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA color image produced from a continuously toned color image by using a smaller number of colors (e.g., 256) is called a “color quantized image.” Previously, the author and colleagues proposed a high‐speed color quantization method which produces an image of almost the same quality as the original. However, if colors in an image change gradually (such as an image produced by computer graphics), false contouring occurs and deteriorates the image quality. To solve the problem, this paper proposes four new methods, three of which are shown by experiments to have excellent dithering effects which overcome the weakness of the conventional error‐diffusion method and are pr

ISSN:0882-1666    

DOI:10.1002/scj.4690211007

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA method to evaluate quantitatively the faint line‐shaped defect existing in the imaging signal of a solid‐state imaging device has been developed. Classifying line‐shaped defects into nondirectional ones for which the direction of the line defect cannot be specified and those of vertical direction, we investigate an evaluation algorithm for each of them and evaluate them by experiments. For nondirectional line defects, noticing that the line defects resemble straight line defects, line defects are detected within an image using Hough transformation. Next, computing the length and contrast of line defects as evaluation parameters, the degree of defect was evaluated. In the computation, efficient processing was attempted by making some additions to the processing method. As a result, detection and evaluation were achieved within a practically reasonable time. Taking into consideration vertical line defects and noticing that defect evaluations by human eye are different depending on frequency ranges of lines, defects of contrast in high‐frequency range using data interpolation and contrast in low‐frequency range using smoothing process were found and then the degree of defects by these contrasts was evaluated. Using the forementioned algorithm, a system was developed for automatic evaluation of line‐shaped defects for experiment and compared with the traditional evaluation by human eye. As a result, good agreement was obtained and the line‐shaped defects of a solid‐state imaging device were evaluate

ISSN:0882-1666    

DOI:10.1002/scj.4690211008

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractRecently, Modulo‐PCM (MPCM) was proposed as one of the waveform speech coding schemes. The MPCM is considered to be a possible alternative to the DPCM. This is because the MPCM has only granular noise without overload although it has the “anomaly errors” instead of the overload noise. The variable bit rate modulo‐PCM (VBR‐MPCM) has been proposed which applies the variable rate coding method to the Modulo‐PCM. This paper proposes the improved variable bit rate modulo‐PCM (improved VBR‐MPCM) whose performance is the same and whose complexity is about half compared with that of the conventional VBR‐MPCM. Moreover, the variable bit rate modulo‐PCM using adaptive predictor (VBR‐MPCM‐AP) also is proposed which uses second‐order pole and sixth‐order zero adaptive predictors instead of the fixed ones used in the improved VBR‐MPCM. From the computer simulation results, it is confirmed that the VBR‐MPCM‐AP is about 0 to 8 dB in segmental SQNR (SQNRseg), which is better than the conventional VBR‐MPCM, MPCM‐AQF and ADPCMs. From the listening test results, it is also confirmed that the proposed VBR‐MPCM‐AP is

ISSN:0882-1666    

DOI:10.1002/scj.4690211009

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractWhen a group of parallel lines pass through an ellipse, the center point between two intersecting points of each straight line is on another straight line passing through the center of the ellipse. Furthermore, a graphical plot of the distance between the two intersecting points vs. a coordinate value (eitherxory) of the center point will form an elliptical shape. These two characteristics of the ellipse are exploited by an algorithm for ellipse extraction. Given an input image of ellipses, a center point map is constructed. Then a Hough transform is used to detect the center line that represents the ellipse. Next, the center line so detected is used to estimate the parameters and to obtain sample pixels of the ellipse. This is followed by a least‐square fitting and high precision parameter value computation. Numerous experiments were conducted which demonstrated the effectiveness of our algorith

ISSN:0882-1666    

DOI:10.1002/scj.4690211010

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY