A study of high density digital recording has been carried out by using MUSE signal. Two types of high performance tape such as metal particle (MP) and metal evaporated (ME) are used for this experiment. It is confirmed that the 8-14 code, which has been adopted for 1/2 inch composite digital VTR, is suitable for not only MP but also ME tapes. An areal density of 1.26μm^2/bit (514Mbpi^2) with byte error rate 3.0×10^<-4> has been obtained.
MUSE, a Hivision transmission system for analog lines. modulates a digital audio signal to a unique form with large redundancy. Digital recording/transmitting of MUSE signal, however, does not require such redundancy. A new coding method for the modulated signal is described in this report. It substantially reduces the bit rate of the signal using vector quantization, taking full advantage of the characteristics of the signal. It can be realized in very simple hardware and has been applied to an experimental MUSE digital VTR. Satisfactory results have been obtained.
In order to realize a single-channel recording of HD baseband signals, a high-efficiency transmission method suitable to analog recording VCR has been examined. In this method, the transmission bandwidth is reduced by considering the redundancy of video image and the human-eye characteristics. As a result, a signal processing method, which we call BASE (Baseband adjacent-line Add-Subtract TCI Encoding Method) has been proposed. In BASE, the add and subtract signals of adjacent two lines in the same field are transmitted with a TCI form. The spectrum analysis in a two dimensional frequency area, and the effect of the transmission noise have been examined. Consequently, we can confirm the feasibility of single-channel recording of HD baseband signals by employing BASE, which can reduce the transmission bandwidth to approximately 69% with almost no picture degradation.
An HD VCR, which can record and reproduce HD baseband signals by using a single-channel recording method, has been developed. The VCR has realized a high picture-quality and long-time recording of wideband HD baseband signals. In this paper, the SNR improvement techniques used in the VCR are described. In a wideband recording system with an FM recording method, a drastic SNR improvement can be obtained by suppressing the triangular noise caused by FM signal Processing. In this study, the optimum equalization characteristics have been analized. Then an equalizer circuit with a dynamic or non-linear property, which can realize linearly descending characteristics by keeping the white-black inverting margin, has been developed. As a result, by improving the performances of both equalizer and emphasis circuits, a total SNR improvement value of 8 dB has been achieved.
EDTV signal format has been studied for achieving higher quality pictures. In order to realize high dynamic vertical resolution, interlaced scanning signals are produced by the arrangement of the same frame signals obtained with progressive scanning camera. The crominance and the high resolution signals are frequency multiplexed with field-line-paired format so as to avoid the crosstalk.
The extension of horizontal luminance bandwidth is one of the subjects of the second generation EDTV, so far, some proposals have been made, which fold down horizontal high component into 4.2MHz band by modulation of subcarrier. Using the transmission model we have proposed before, step responses of horizontally extended bandwidth signals are compared varing the subcarrier frequency, subcarrier phase error in demodulator, and so on.
This papaer presents a new NTSC system : NTV Mode1.5,situated as an intermediate system between the side panel system (NTV Mode1) and the letter box system (NTV Mode2). In this system. wide screen image with an aspect ratio of 9 : 16 is encoded to be reproduced on the conventional NTSC receivers maintaining about 90% of original image. NTSC compatibility and feasibility of this system as a wide aspect advanced televiosion have been confirmed through hardware evaluation.
Various data broadcasting services can be transmitted using the Data Channel of DBS. The Still Picture broadcasting system which contains graphics, characters and sound has been studied as one of the services. Subjective tests have been conducted for comparison between several picture coding methods. The transmission format and receiver systems will also be discussed.
The effects of both continuous Gaussian noise and burst Gaussian noise on TV picture degradation were studied by using a Gaussian noise generator which can control noise parameters such as power, ACR, duration, and occurrence frequency. The disturbance was subjectively evaluated. The tendency of the picture degradation against the both noises was the same. However, when the noise power was constant, the mean opinion scores for the burst noise approached to those for the continuous noise as increase of the occurrence frequency at constant burst duration.
As application of picture enhancement technique to color natural pictures has been investigated. Two appication methods have been considered; one processes RGB uniformly based on histogram information of Y-component and the other deals with HLS components which are obtained by a color space conversion. The quality of processed pictures was mostly satisfactory.
In order to obtain suggestions for the application to neural networks, basic characteristics of visually recognizing space positions, gradients and time durations are investigated experimentally. The experimental results indicate that a kind of symbolic long-term-memory takes part in recognitions of continuous objects such as positions and gradients, and that the recognition error of time duration less than 5 seconds is increased in proportion to the about 0.3th power of duration.
Since a multi-view lens-plate 3D image is displayed with picture data of many views, it is necessary to compress the data before transmission and recording. In this paper, a method of data compression using the geometrical relations between views of still, opaque, and color objects is proposed. By computer simulation, the estimated number of bits or a compressed data is about 1.5 times greater than that of a stereoscopic image under the condition of the same resolution. Experimental data obtained by camera were compressed and expanded by this method, and 3D feature of the object was reproduced.
We studied on the objective measurements of the "Sensation of Reality" by utilization of the postural control response. We measured the subjects' body sway induced by the rotation 3D-image and 2D-image. As a result, in the case of the rotation 3D-image, there existed the component corresponding to the rotation image in the spectra of the subjects' body sway, but no conspicuous one in the case of the 2D.