Facsimile services over PSTN (Public Switched Telephone Network) are investigated, especially an error correcting G3,a supper high speed G3 and G4,which use high speed or bi-directional Modems such as V. 33 (14.4 Kbps) or V. 32 (9.6Kbps). From the viewpoit of communication efficiency, applied media and protocol, the sevice aspect of new facsimile services over PSTN is categorized. As a result, it is pointed out that there exist the following two types of facsimile servies : (1) supper high speed G3 communication service using V.33 Modem and PPS (Partial Page Selection) method, (2) G4 communication service with V.32 Modem.
This paper describes an Intelligent Video Communication System which can transmit video images through a very low bit rate (lower than 10 kb/s) transmission line with the use of picture recognition and picture processing techniques. At the sending side, the motion of a face is picked up and recognized by three feature points of the face. At the receiving side, it can be reconstructed by the help of image data base of the face on a real time basis.
A DPCM picture coding with adaptive prediction is discussed. The method prevents from blurring edges or contours of reconstructed images. The information on the edges is derived from the reconstructed neighboring pixels. Therefore, no additional information is required to select a suitable prediction. The effectiveness of the method compared with fixed type DPCM is shown by the simulations.
This paper describes a study of coded aperture imaging techniqes for laserproduced plasma diagnostics. In order to obtain a three-dimensional compressed core image of laser-imploded target, we have developed a new technique of computed tomograph (CT) which using two othogonal URA coded aperture imaging cameras. We also developed a new coded aperture imaging techniqe, penumbralimaging, to observe thermonuclear reaction region.
We investigate a resolution of SAR reconstructed images using a digital algorithm proposed by C.Wu. A computer simulation shows that this method makes a resolution for two point targets about 1.5 times worse than expected.
In order to clarify design concepts of Hi-vision camera tubes with excellent resolution capability, predominant factors in deciding the resolution of Hi-vision pickup tubes have been investigated by manufacturing experimental 2/3-inch tubes and anaiyzing electron-optical properties. The results obtaind were as follows, (1) the lower the magnification of beam spot is, the higher the resolution capability is. (2) the resolution is limited by the beam bending and optical lenses. Particularly it was found that the beam bending tended to be ignored in conventional design concepts of camera tubes was concerned with the resolution capability in Hi-vision image format. As the result that the suppression of the beam bending was tried, the high resolutional camera tube could be realized for Hi-vision.
This paper shows the transient behavior of a Ultra High Speed Framing Camera using the proximity focused image intensifier with an additional external transparent electrode. The experiment of fast gating of proximity focused image intensifier by supplying electrical pulse voltage to photocathode or to the additional external transparent electrode is acoomplished. By utilizing an external transparent electrode, gating time of subnanosecond is available. Experimental results can be analysed sufficiently and accurately, by using RLC transmission line equations.
2-dimensional photo-detectors whose sensitivity is as high as that of photomultipliers have been strongly required and recently the 2-dimensional photon counting imaging system with single photoelectron detection ability was developed. Operation principle and some examples of its application are presented.
We have developed new image sensor chips using thyristor shift register. The sensor chip integrates a 174-dots photo-transister array, a shift register formed by serial connection of thyristors and a pair of differential current switches. The simple scanning circuit reduces the width of the sensor chip and made it possible to operate with a simple driving circuit. We have fabricated an A4 size contact image sensor by mounting 10 chips linearly on an alumina substrate with conductive circuit pattern. This sensor is capable of scanning an A4 size document at a resolution of 8 dots/mm in 2.5 seconds.
An improvement of reading speed and color reproductibility in the contact type color image sensor that uses light-switching method is described. New structured light sources results twice of reading speed and 30-40% reduction of color difference comparing with the former type. A prototype model, introduced the light sources, reads B4-size document in 46 seconds at 16 dots/mm resolution.
Canon Color Laser Copier 1 is the first digital color copier to print out an plain paper. A main feature of Color Laser Copier 1 is high image quality and many intelligent functions as a digital copier. In order to obtain that, we have developed a high speed and real time digital image processer by means of many image processing techniques. They are 16 pel/mm high resolution scanning system using contact color CCD sensor, color compensation (maskig, UCR, UCA), color convertion, edge enhancement and so on.