Showing papers on "Video quality published in 1979"

Facsimile communication system

Abstract: PURPOSE:To obtain an efficient communication without deterioration of the video quality, even if the channel is altered by reading out the characteristic data corresponding to the line from a memory circuit and adjusting a modulation/demodulation device, equalizer and waiting time. CONSTITUTION:The system is provided with a memory circuit 11 which stores the characteristics per line connected to specific correspondence party, such as adjusting value of an equalizer, amplifier gain of modulation and demodulation device, and waiting time of response signal. Further, when a communication control circuit 10 reads out the characteristic data corresponding to the said line from the circuit 11 at the start of correspondence and the modulation and demodulation devices 6 and 8, equalizer 7 and the waiting time are adjusted, allowing to make efficient communication without incurring the deterioration of video quality, even if the facsimile channels are changed.

Video signal processing system

Abstract: PURPOSE:To increase the data compression rate of profile coding to the picture after processing without accompanying the deterioration of reproduced video quality, by performing the smoothing processing suitable for the complexity of picture for each part to the original picture sampled. CONSTITUTION:The complexity of the video element pattern in block is taken as the number of profile lines present in the block, and the greater value is regarded as complex, and on the other hand, the patterns which can be smoothed or omitted are arranged in the order from the one applicable to the block having the complexity lowermost to the simplest and are grouped. Further, when the complexity of block is 1, all the processing of groups 1, 2 and 3 is applied and when it is 2, that of the groups 1, 2 and when more than 3, the processing of only group 1 is applied. As a result, the profile data after processing can increase the effect of data compression at coding.

Video transmission system

Abstract: PURPOSE:To enable to judge the video quality of the received picture at the transmission side and to reduce the video transmission time, by returning a part of the received picture to the transmission side with detection. CONSTITUTION:The interface 3A of the transmission side A transmits the information from the read-in section 1A to the reception side B and records the local picture 16A via the write-in section 10A. Further, at the receiving end B, the picture memorized in the write-in section 10B is obtained as the local picture 16B. Then, the corresponding part of the recorded picture by the write-in sections 10A and 10B are respectively detected with the concentration detection means 18A and 18B and the integration value of concentration is obtained. The integration value of the means 18B is returned to the transmission side A, where it is compared with the integration value of the means 18A resulting in judging the received video quality.

Video signal sampling method for small picture in television receivers

Abstract: PURPOSE:To enable to receive the small screen of excellent video quality, by performing the timing of sampling at the second field at the intermediate place of the sampling timing of the first field. CONSTITUTION:TV reception signal received on the antenna 3 is inputted to the large and small screen reception circuits 1 and 2 via the brancher 4. The reception circuits 1 and 2 consist of the tuners 11 and 21, intermediate frequency amplification and detection circuits 12, 22, and synchronism separation circuits 13, 27, and the signal is displayed on the Braun tube 15 via the video amplifying circuit 14. The video signal for small screen is written in the memory 24 based on the instruction of the control circuit 28. Or, it is read out from the memory 24. Further, the range of sampling is narrowed suitably for the reproduction as a small screen, so that the screen of excellent resolution can be obtained with the same sampling frequency or memory capacity. Further, in the second field, the sampling is made in the intermediate timing as that in the first field, allowing to increase the effect.

Adjusting circuit for video quality

Abstract: PURPOSE:To automatically control the video quality according to input electric field, with the control means of the video signal by AGC voltage. CONSTITUTION:When the input electric field is weak, the reverse AGC voltage is increased and the transistor 3 is turned on. Thus, the transistors 7, 8 are turned off and the transistors 6, 9 are turned on and also the transistors 13, 14 are turned on. Thus, the video signal fed to the terminal 18 is outputted through the transistors 13, 14, 19 and the high band component is grounded with the capacitor 17. As a result, soft picture in which the high band components are dull is obtained and no noise is eminent. With the input electric field stronger, the operation is converse and the video signal is outputted through the transistors 3, 17 and normal picture not affected with the capacitor 17 can be obtained in this case.

Narrow band video trsnsmission system

Abstract: PURPOSE:To increase the video quality of reproduction, even if noise is intruded, by performing the request of retransmission and rewriting the part causing error for the reception side video memory content, through the error detection at the reception side.

Improvement method of video quality in signal processing

Abstract: PURPOSE:To improve the video quality, by obtaining the output video elements with higher density than the sampling video elements. CONSTITUTION:The video element signal S(i,j) read in is made quantized in five values (S5 to S1) in the order of greater black signal. Further, the video element S(i,j) is made fine into subcells Pij(a) to Pij(d). When the video element S(i,j) is at maximum level S5, Pij(a) to Pij(d) are all made to black (1) and are all white (0) at minimum level, and at intermediate levels S2 to S4, the subcells are burried with the signal (black) in the specific order.

Interpolation system of deframing of television signal

Abstract: PURPOSE:To increase the video quality of inserted picture, by taking broader the dynamic interpolation area to perform interpolation suitable for the dynamic region than the region judged as the dynamic region, after removing the region in which the static region is misjudged as the dynamic region with the superposition of noise. CONSTITUTION:One frame of the input TV signal is divided into suitable blocks, the frame differential value is accumlated as to all the video elements in each block, the absolute value of the accumulated value is compared with the threshold value predetermined, the video element in the block more than the threshold value is judged as the video element in the dynamic region, and the video elements other than it are discriminated as the video elements in the static region. At this time, the threshold value is increased so that no dynamic region 1 misjudged with noise can not be caused, the dynamic insection region hatched portion performing the interpolation suitable for the dynamic region is determined by extending the dynamic region block to left and right, and the remaining regions are taken as the static interpolation region performing the interpolation suitable for the static region. For example, the video elements in the dynamic region are interpolated at the first and second field by using the video element value in the preceding or subsequent field.

Delivery unit for coded signal

Abstract: PURPOSE:To perform picture reproduction of high density and video quality, by comparing the memory content with the output of the latch circuit with the comparator when the output from the decoder is an intermediate tone signal and determining the video element sectioned into two and burying the space from the result. CONSTITUTION:When the output from the line counter 19 is an odd number signal being small apperture, the output from the latch circuit 11 is outputted from the OR circuit G2 via the output line 4. Further, when the output from the line counter 16 is an even number signal, the output from the circuit 11 is outputted from the circuit G2 via the output line, if the output of the decoder 14 is black or white signal. Further, when the output from the decoder 14 is an intermediate tone signal, the comparator 13 compares the content of the memory 12 with the output of the circuit 11, and the voltage Vcc is outputted from the OR circuit G2 via the line Sig or resistor R through the output line 1 or 2 according to the result, determining two divided video element and burrying the space. Thus, the video reproduction of high density and high video quality can be made.

Facsimile delivery system

Abstract: PURPOSE:To prevent the lowering in the video quality, due to jitter by detecting the center of each bit of the video signal from the transmitter section read in and by performing phase adjustment again when the detection point is shifted by a given amount. CONSTITUTION:The crystal oscillator 1 at the reception side is a high oreder colck source, the output is divided by 16 with the counter 2, generating the recording clock, and one circulation is made with n counts corresponding to the number of bits of one line at the counter 3. Further, the video signal read in with the transmitter is sampled with the period the same period as the recording clock at the reception side, the faxsimile signal E received at the reception side is differentiated 4, setting the counters 2 and 3 via the gate 5. Further, the output decoding 6 the output of the counter 3 controls the gaste 5. Further, phase alignment is made so that the center of each bit of the signal E can be detected, and when the detected point is shifted by a given amount, the lowering in the video quality due to jitter can be prevented.

Detection and processing unit for code error

Abstract: PURPOSE:To prevent the deterioration of video quality and to increase the compression rate by making unnecessary the parity bit, by recording the video signal priorto one scanning line at the occurrence of delivery error based on the result of judgement of the number of video elements.

Video quality improving method

Abstract: PURPOSE:To obtain the reproduced picture in response to the video signal level, by deflecting the light beam toward subscanning line according to the amplitude of video signal and giving wobbling. CONSTITUTION:The video information signal is separated into the video signal amplitude-modulated with the demodulator and the synchronized signal. The video signal performs luminance modulation to the optical beam according to the level via the amplifier and the synchronizing signal produces the saw tooth waves to oscillate the optical beam toward scanning. After the video signal passes through the suitable correction circuit, it is inputted to the deflection circuit so that the optical beam is oscillated toward subscanning. Thus, the optical beam luminance- modulated with the video signal is subjected to the deflection according to the level of the video signal even toward subscanning. Then, since the optical beam is scattered two dimensionally on the screen, no saturation of luminance on the screen is made and the tone can be increased.

Sensitivity Study and Optimization of Predictive Systems for Transmission of Video Signals

Abstract: A method is proposed to optimize the prediction coefficient of a first order predictor. The optimization is with respect to the sensitivity of variations in statistics of the video signal. Given the characteristics of human vision, it has been shown that the DPCM is not worse than the PCM with respect to the sensitivity to variations in the input video signal statistics, but is even better than the PCM. Also, the following point is made clear. If an encoding system is designed with a = as (?Mo) providing the satisfactory quality for the picture with ? = ?Mo, this system will yield picture of better or equal quality as for ? = ?Mo for any other picture.