SU1285503A1 - Device for quantizing video signals - Google Patents

Abstract

The invention relates to automation and computing, in particular to devices for quantizing video signals. The purpose of the invention is to improve the accuracy of the device and expand the area of its application due to the possibility of quantizing and recording video signals in different subbands. The device for quantizing video signals contains a recording unit, a digital-analog converter, an analog-digital converter, a decoder, two operational amplifiers, a signal module driver, a memory element, a subtractor, a counter, a generator of reference signals, a zero transition signal generator, and a switching element. 1 il.

Description

The invention relates to automation and computing, in particular to devices for quantizing video signals.

The aim of the invention is to improve the accuracy of the device and expand its scope by providing the possibility of quantizing and recording video signals in different subbands. ten

The drawing shows a functional block diagram of a device for quantizing video signals.

The device has the first input 1,

At the same time, the pulses from the decoder 13 are output to the control input of the key 4 at the times corresponding to the peak values of the input oscillation, and to the clock input of the analog-digital converter 14, the pulses from the output of the decoder are delayed relative to the first ones by a certain amount. When the input signal drops to zero level at modulation sites, the decoder 13 outputs pulse sequences phased with an error that does not exceed ... the first operational amplifier 2 forms 5 with the appearance of a carrier oscillation signal on the control input of the key 4 pulses from the decoder 13 are output at the moments of time corresponding to the peak values of the input oscillation and to the synchronizing input of the analog-digital converter 14, the pulses from the output of the decoder delay relative to the first ones on the determinant this value. When the input signal dips to zero level at modulation sites, the decoder 13 generates pulse sequences, phased with an error,

globalizer 3 signal module, key 4, memory element 5, subtraction unit 6, second input 7, second operational amplifier 8, third input 9, shaper 10 signals of zero transitions, 2Q counter 11, generator 12 of reference signals, decoder 13, analog a digital converter 14, a switching element 15, a quarter input 16, a digital-to-analog converter 17, a recording unit 18, a development drum 19 and a recording medium 20.

The device works as follows.

fillers from the output of the decoder 13 synchronization with the latter. Thus, the key 4 in the peak places of the input oscillation is opened with the help of a pulse from the output of the decoder 1, and the memory element 5 stores the amplitude value of the input signal module.

Next, the input signal envelope, which is a video signal, is fed to the subtraction unit 6, and a second input is fed to its second input, which is the second input 7 of the device.

The input signal is the corresponding voltage, corresponding to

the amplitude-modulated oscillation is fed to the first input 1 of the device, which is the input of the first operational amplifier 2. From the output of the first operational amplifier 2, the signal enters the inputs of the former 3 of the signal module and the former 10 zero-crossing signals. The output signals of the latter are set to the initial state of the counter 11, counting the pulses of the generator 12. The frequency of the pulses of the generator 12 is equal to

,

where N is the conversion factor of the counter; f - carrier frequency

input signal; F is the frequency corresponding to the instability of the frequencies of the carrier oscillation of the input signal and the generator reference signals.

therefore, a decoder 13 is connected, 55 connected. The number of levels and the scale to the outputs of counter 11 provide quantizing in the selected subband a sequence of pulses, the sync-input video signal is set at phase and frequency, with the switching element 15, the first real oscillation of the input signal. which entrance which is the fourth

The waves from the output of the decoder 13 are in sync with the latter. Thus, key 4 at the peak locations of the input oscillation is opened with a pulse from the output of the decoder 13, and memory element 5 stores the amplitude value of the input signal module.

Next, the input signal envelope, which is a video signal, is fed to the subtraction unit 6, and its second input, which is the second input 7 of the device, is supplied to the constant value of the subband of the displayed video signal. From the output of block 6, the signal is amplified by a second operational amplifier 8,

the gain of which is controlled by the third input 9 of the device, after which it corresponds to the subband size of the displayed video signal. For example, at a gain factor of ten, an analog-to-digital converter 14, connected to the output of the second operational amplifier 8, converts the values of the video signal, which are

are located in a certain one tenth part (specified by the voltage value at the second input 7 of the device) of the whole range of the input video signal. The output code of the analog-to-digital converter 14 through the switching element 15 is fed to the digital-to-analog converter 17, which converts the input code into the output 16 of the device and is connected to a constant voltage source corresponding in size to one of the logical levels of the output code of the analog-digital converter 14 The recording unit 18 records the input voltage on the recording medium 20 (e.g., photographic) fixed to the unwinding drum 19.

Thus, the proposed device provides registration on the recording media of a video signal in a selected sub-band in size with the required number of levels and a quantization scale. At the same time, high accuracy of signal processing is provided due to adjustment of the detection process and conversion to - fluctuations of the carrier frequency of the input signal.

Claims (1)

Invention Formula A device for quantizing video signals, comprising a recording unit, a digital-to-analog converter, the output of which is connected to the input of a recording unit, an analog-to-digital converter and a decoder, the first output of which is connected to the first input of the analog-digital converter, characterized in that expanding its scope, application by enabling quantizing and recording video sequences in different subbands, it contains the first operational amplifier, the input of which is the first device input, driver the signal module, the input of which is connected to the output of the first operational amplifier, the key, the first input of which is connected to the output of the driver signal modulus, and the second input is connected to the second output of the decoder, the memory element whose input is connected to the key output, the subtraction unit, the first input of which is connected with the output of the memory element, and the second input is the second input of the device, the second operational amplifier, the first input of which is connected to the output of the subtractor, the second input is the third input of the device, and the output is connected to the second input of the analog-digital converter, the counter, the outputs of which are connected to the inputs of the decoder, the generator is signals, the input of which is connected to the first input of the counter, the zero-crossing signal generator, the input of which is connected to the output of the first operational amplifier, and the output is connected to the second input of the meter, and the switching element, the first input of which is the fourth input of the device, the other inputs are connected to the outputs of the analog-to-digital converter, and the outputs are connected to the inputs of the digital-to-analog converter.