JPH04292084A - Video signal pedestal level transfer system - Google Patents

Abstract

PURPOSE:To efficiently transfer video signals while multiplexing prediction coded video signals by sampling the pedestal level value of the digital video signals for each scanning line, and removing horizontal blanking period. CONSTITUTION:The pedestal level value of the digital video signal without horizontal blanking period to be outputted from a luminance/chrominance signal separation means 31 is eliminated is sampled for each scanning line of the digital video signal by a pedestal level extraction means 34. This sampling pedestal level value is outputted after multiplied with predictive coded digital video signals without horizontal blanking period. Thus, the video signal can be efficiently transferred and the flickering noise can be prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal pedestal level transmission system that is applied to a video transmission apparatus that performs YC separation (luminance signal/chrominance signal separation) of a video signal and band compression of intraframe codes and the like.

[0002] In recent years, with the increasing need for video transmission,
There are great expectations for the development of image communication systems configured using video transmission devices and the like. In addition to transmission and exchange technologies, the technologies that make up this system include technologies unique to image information, such as image input/output, image compression and encoding, image processing, and image databases.

[0003] Image information (video signal) generally has a huge amount of information, so if it were to be transmitted as is, a broadband transmission line would be required, which would increase the cost. Therefore, it is necessary to efficiently transmit images using techniques such as image compression encoding and image processing.

However, in this case, the image quality may deteriorate, so there is a need for a video signal pedestal level transmission system that can efficiently transmit video signals with high quality.

[0005]

[Prior Art] In a conventional video transmission device, the video pedestal level value is not specially transmitted, and the video pedestal level value during the vertical blanking period (vertical synchronization signal) of the transmitted video signal is transmitted by the receiving device. n pieces of data were sampled, and the average value was used as the video pedestal value and played back in field units.

[0006]

[Problems to be Solved by the Invention] However, in the conventional method described above, since the average value of the video pedestal level value during the vertical blanking period of the video signal is reproduced as a representative value, fluctuations in the video pedestal level value will vary in field units (field frequency: 59.94 Hz).

This means that the visual characteristics of flicker noise are
Considering that it is detected conspicuously near the field frequency, the video pedestal value is 1LSB (Least Significant
Even when there is a change in bit), there is a problem in that flicker noise appears in the reproduced video displayed on the monitor, and in fact, the quality of the reproduced video deteriorates due to this drawback.

[0008] The present invention has been made in view of the above points, and it is an object of the present invention to provide a video transmission device or the like that can efficiently transmit video signals and obtain high-quality reproduced video without flicker noise. The purpose of this project is to provide a video signal pedestal level transmission system that enables

[0009]

[Means for Solving the Problems] FIG. 1 shows a diagram of the principle of the present invention. In the figure, 30 is an analog/digital conversion means, which converts an analog video signal S obtained by imaging into a digital video signal.

31 is a luminance signal/chrominance signal separation means;
The horizontal blanking period of the digital video signal outputted from the analog/digital conversion means 30 is removed to output other digital video signals including a luminance signal and a color signal.

34 is a pedestal level extraction means;
It samples and outputs the pedestal level value of the digital video signal from which the horizontal blanking period has been removed, which is output from the luminance signal/color signal separation means 31.

[0012] 32 is a predictive encoding means, and the luminance signal/
The digital video signal from which the horizontal blanking period has been removed, which is output from the color signal separation means 31, is predictively encoded and output.

Reference numeral 33 denotes a multiplexing means, which outputs the pedestal level value outputted from the pedestal level extraction means 34;
The signal is multiplexed with a digital video signal from which the horizontal blanking period has been removed and which has been predictively encoded, which is output from the predictive encoding means 32, and then output.

[0014]

According to the present invention described above, the pedestal level value of the digital video signal from which the horizontal blanking period has been removed, which is output from the luminance signal/chrominance signal separation means 31, is extracted from the digital video signal by the pedestal level extraction means 34. The sampled pedestal level value is sampled every scanning line of
The horizontal blanking period outputted from the predictive encoding means 32 is removed, and the signal is multiplexed with the predictively encoded digital video signal and output.

[0015] If the multiplexed digital video signal output in this way is processed on the receiving side and displayed on a monitor,
The imaged object can be reproduced according to the video signal obtained by imaging, and flicker noise can be prevented from occurring during this reproduction.

This is because the pedestal level value is sampled and transmitted for each scanning line of the digital video signal. That is, even if the pedestal level value fluctuates by about 1 LSB due to quantization noise or the like when the video signal S is converted into a digital video signal by the analog/digital conversion means 30, the pedestal level value for each scanning line will be changed on the receiving side. In order to be reproduced, the fluctuation is at a frequency of 15.734
Hz line unit (scanning line unit), and due to visual characteristics,
This is because it is not detected as flicker noise on the monitor.

Conventionally, since the average value of the pedestal level during the vertical blanking period of the video signal was used as a representative value for reproduction, the fluctuation of the pedestal level value fluctuated in units of fields at a frequency of 59.94 Hz, which was noticeable in terms of visual characteristics. Therefore, even if the pedestal level value fluctuated by 1LSB due to quantization noise or the like, flicker noise appeared on the monitor.

Further, in the present invention, an arbitrary number of average values of pedestal levels obtained by sampling multiple times within one scanning line are multiplexed together with a digital video signal from which a horizontal blanking period has been removed and which has been predictively encoded. Flicker noise can be prevented in the same manner as described above even if the signal is converted into a digitized signal and transmitted.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing the configuration of a transmitting section of a video device using the video signal pedestal level transmission method according to an embodiment of the present invention, and FIG. 3 is a diagram showing the configuration of a receiving section of the video device.

In FIG. 2, S is a composite video signal (analog signal), which is obtained by performing blanking on a video signal captured by an imaging section (not shown), and then adding a horizontal synchronization signal and a vertical synchronization signal. .

FIG. 4 shows the configuration of one scanning line of this composite video signal S. In this figure, S1 is a horizontal synchronization signal, S2
is a color burst signal, PL is a pedestal level, and S3 shown by a broken line is a luminance signal Y and a color signal C.

The composite video signal S is first input to the A/D (Analog/Digital) converter 2 of the transmitter shown in FIG. 2, where it is converted into a digital signal (digital composite video signal) DS and converted into a luminance signal The signal is output to the color signal separation section 3.

The luminance signal/color signal separation section 3 removes the horizontal blanking period (horizontal synchronization signal) from the digital composite video signal DS, and generates burst data DS2 corresponding to the color burst signal S2 shown in FIG. 4 and the pedestal level. P
The pedestal level value DPL corresponding to L is output to the video pedestal level value insertion section 4, and the luminance data D corresponding to the luminance signal sampled in the period corresponding to the luminance signal sample period and the color signal sample period shown in FIG.
Color data DC corresponding to Y and the color signal is output to the time division multiplexer 5.

The time division multiplexing unit 5 time-divisionally compresses the color data DC and time-division multiplexes it during the horizontal blanking period of the luminance data DY. As a result, a time division multiplexed signal TS having the format shown in FIG. 5 is generated and output to the predictive encoding section 6. However, the time division multiplexed signal TS in the format shown in FIG. 5 is obtained from the composite video signal S of one scanning line shown in FIG. 4.

The predictive encoding section 6 performs intra-frame predictive encoding on the time division multiplexed signal TS, and outputs video encoded data D1 obtained by this predictive encoding to the video frame multiplexing section 7.

On the other hand, the video pedestal level value insertion section 4 multiplexes the pedestal level value DPL and the burst data DS2, and outputs this to the video frame multiplexing section 7 as control data D2.

The video frame multiplexing unit 7 multiplexes the input video encoded data D1 and control data D2 with the self-generated video frame synchronization pattern, as shown in FIG. 6(a).
A video frame F shown in is created and outputted to the buffer memory 8. FIG. 6(b) shows the structure of the control data D2.

The buffer memory 8 sequentially stores each piece of data constituting the video frame F, and outputs the data to the transmission line frame multiplexer 9 in the stored order.

The transmission path frame multiplexing section 9 multiplexes the audio signal VS output from the audio processing section (not shown) onto the video frame F to create a transmission video frame F1, and transmits this to the transmission path (not shown). Send to.

[0030] This transmitted transmission video frame F1 is as follows:
The signal is input to the receiving section shown in FIG. 3 via the transmission path. This receiving section performs an operation opposite to that of the transmitting section shown in FIG. 2, thereby finally obtaining a composite video signal S' corresponding to FIG. 4.

[0031] However, since the signals output from each part of the receiving section, which will be explained below, correspond to the signals output from each part of the transmitting section, they are given the same reference numerals, but in order to clarify the distinction between the transmitting and receiving sections, , add ′ to the upper right of the symbol.

The transmission video frame F1 inputted to the receiving section shown in FIG. 3 is first inputted to the transmission path frame separation section 10.

The transmission path frame separation section 10 separates the audio signal VS' from the transmission video frame F1 and outputs it to the audio processing section, and also stores the video frame F' obtained by separating the audio signal VS' in a buffer memory. Output to 11. As a result, the video frame F' is stored in the buffer memory 11.

The stored video frame F' is output to the video frame separation section 12, where the video encoded data D1' and the control data D2 are synchronized by the video frame synchronization pattern of the video frame F'. ′ and are separated. The separated video encoded data D1' is output to the predictive decoding section 13, and the control data D2' is output to the video pedestal level value reproduction section 14.

[0035] The predictive decoding unit 13 receives encoded video data D.
1' predictive decoding is performed to reproduce the time division multiplexed signal TS', which is output to the time division demultiplexing section 15.

[0036] The time division demultiplexer 15 receives the time division multiplexed signal T.
The time-division multiplexed color data is separated and reproduced during the horizontal blanking period of the luminance data of S', and the reproduced color data DC' and the luminance data DY' from which the color data is separated are reproduced.
and is output to the luminance signal/color signal combining section 16.

On the other hand, the video pedestal level value reproduction section 14
reproduces the pedestal level value DPL' and the burst data DS2' from the input control data D2', and outputs them to the luminance signal/chrominance signal synthesis section 16.

The luminance signal/color signal synthesis section 16 synthesizes the input color data DC' and luminance data DY' with the pedestal level value DPL' and the burst data DS2', and also generates horizontal blanking data generated by itself. By combining period data (data that becomes a horizontal synchronizing signal) or vertical blanking period data (data that becomes a vertical synchronizing signal) with each of the previously synthesized signals, a digital composite video signal DS' is reproduced and D/ A(Digital/An
alog) output to the converter 17.

The D/A converter 17 converts the digital composite video signal DS' into an analog signal. As a result, a composite video signal S' is obtained.

The obtained composite video signal S' of one scanning line
is output to an image receiving section (not shown). Thereafter, similarly, the composite video signals S' are sequentially outputted to the image receiving section, so that images corresponding to the composite video signals S' are displayed on the monitor of the image receiving section.

[0041] On the monitor on which this image is displayed, flicker noise as described in the conventional example does not appear.

This is done by sampling the pedestal level value DPL of the digital video signal DS for each scanning line by the video pedestal level value insertion unit 4 of the transmitting unit shown in FIG. This is because the signal is transmitted as the transmission video frame F1, and the receiving section shown in FIG. 3 reproduces the pedestal level value DPL' for each scanning line.

That is, even if the pedestal level value fluctuates by about 1 LSB due to quantization noise etc. when converting the video signal S into the digital video signal DS in the analog/digital converter 2, the reception part This is because since the pedestal level value is reproduced, its fluctuation becomes line-by-line (scanning line-by-scanning line) at a frequency of 15.734 Hz, and due to visual characteristics, it is not detected as flicker noise on the monitor.

Further, the video pedestal level value inserting unit 4 of the transmitting unit inserts the pedestal level value D obtained for each scanning line.
An arbitrary number of average values of PL may be output, and this average value may be reproduced as the representative pedestal level value DPL' in the receiving section. However, the pedestal level value D
The arbitrary number of PLs is within the number of scanning lines in a frame.

[0045]

[Effects of the Invention] As explained above, according to the present invention,
In a video transmission device or the like, it is possible to efficiently transmit a video signal, and there is an effect that high quality reproduced video without flicker noise can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is a diagram showing the configuration of a transmitting section of a video device using a video signal pedestal level transmission method according to an embodiment of the present invention.

FIG. 3 is a diagram showing the configuration of a receiving section of a video device using a video signal pedestal level transmission method according to an embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a decoded video signal input to the transmitter shown in FIG. 2;

FIG. 5 is a schematic configuration diagram of a time division multiplexed signal output from a time division multiplexer of the transmitter shown in FIG. 2;

FIG. 6 is a schematic configuration diagram of a video frame output from a video frame multiplexing section of the transmitting section shown in FIG. 2;

[Explanation of symbols]

30 Analog/digital conversion means 31 Luminance signal/color signal separation means 32 Predictive encoding means 33 Multiplexing means 34 Pedestal level extraction means S Video signal

Claims (2)

[Claims] Claim 1: A video signal (S) obtained by imaging is converted into a digital video signal by an analog/digital conversion means (30), and separated into a brightness signal and a color signal by a brightness signal/color signal separation means (31). At the same time, the horizontal blanking period of the digital video signal is removed, and the digital video signal is predictively encoded by the predictive encoding means (32), and then multiplexed and transmitted by the multiplexing means (33). The device includes pedestal level extraction means (3) for sampling a pedestal level value of the digital video signal.
4), and the pedestal level extraction means (34) extracts the pedestal level value from one of the digital video signals.
The sampled pedestal level value is sampled for each scanning line, and the multiplexing means (33) multiplexes and transmits the sampled pedestal level value together with the digital video signal from which the horizontal blanking period has been removed and which has been predictively encoded. A video signal pedestal level transmission system characterized by: 2. Multiplexing an arbitrary number of average values of a plurality of pedestal levels obtained by sampling within one scanning line with a digital video signal from which the horizontal blanking period has been removed and which has been predictively encoded. 2. The video signal pedestal level transmission system according to claim 1, wherein the video signal pedestal level is transmitted.