JPH0244986A - Receiver for band compression television signal - Google Patents

Abstract

PURPOSE:To simplify an additional component and to make a receiver small in size by using a field memory in an inter-field interpolation circuit provided to the processing system for a luminance signal and that in an inter-field interpolation circuit provided to the processing system for a chrominance signal respectively so as to execute a still picture display function. CONSTITUTION:A one-field luminance signal is stored in a field memory 10 in the inter-field interpolation circuit 9 in the still picture display mode and while the still picture display mode is selected, the stored luminance signal is repetitively outputted. On the other hand, a one-field chrominance signal is stored in a field memory 22 in the inter-field interpolation circuit 21 in the still picture display mode of a chrominance signal and while the still picture display mode is selected, the stored chrominance signal is repetitively outputted. Thus, the same luminance and chrominance signals are repetitively outputted and the still picture display is executed. Thus, the still picture display function is executed by the addition of simple constitution.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to the so-called MUSE (Multipl
e 5ub-nyquist Sampling En
The present invention relates to a receiver for compressed band television signals according to the codir+g) system, etc., and is particularly intended to realize a static display function.

[Prior art] The baseband bandwidth of high-definition television signals is approximately 30
[t4Hz], which cannot be transmitted using one channel of current satellite broadcasting, and in order to transmit it, it is necessary to compress the band to about 8 [HH2].

The so-called MUSE system has been proposed as one of the systems for compressing and transmitting high-definition television signals.

This MUSE method uses a band compression method as exemplified below. (1) The time axis of the color signal is compressed to 1-/4 and multiplexed in the horizontal blanking period of the luminance signal.

(2) In static areas of the image, use incrace to the driver by inter-field, inter-frame offset sampling. (3) In the moving region of the image, use line-to-line offset 1 to 1 line interlace. (4) Motion compensation keeps resolution degradation to a minimum during panning and tilting.

Therefore, in the receiving device, a band expansion configuration compatible with these band compression methods is required.

[Problems to be Solved by the Invention] Recently, television receivers with a static display function have appeared. Therefore, it is desirable that a receiving device that receives MUSE television signals also have a static display function. In particular, in the case of high-definition television signals, the resolution is high, and the demand for a still display function is considered to be high.

However, as described above, the MUSE television signal is different from the so-called NTSC television signal in its signal format 1, so existing static display configurations cannot be applied as is.

The present invention has been made in consideration of the following two points, and is a compressed band television signal that can realize a static display function with a simple configuration for compressed band television signals according to the MUSE method, etc. It is intended to provide a receiving device.

[Means for Solving the Problem] In order to solve the problem, in the present invention, each of the luminance signal and chrominance signal processing systems processes driver 1 to ink race by inter-field offset sampling with respect to a still area in a field memory. Still image display in a receiver for compressed band television signals comprising an interfield interpolation circuit that restores dot interlace to the original state using line-to-line offset sampling for a moving region Luminance signal holding means for storing one field of luminance signals via the intra-field interpolation circuit in a field memory in the inter-field interpolation circuit of the luminance signal system to hold the luminance signal when the mode is selected; When the still image display mode is selected, color signal retention stores one field of color signals via the intra-field interpolation circuit in the field memory of the color signal system's inter-field interpolation circuit and holds the color signal. A still image is obtained by the signals held by the luminance signal holding means and the color signal holding means.

[Function] When the still picture display mode is entered, the luminance signal holding means stores the 1-field luminance signal in the field memory in the interfield interpolation circuit, and stores this luminance signal while the blue contest still picture display mode is selected. The stored luminance signal is repeatedly output. On the other hand, the color signal holding means stores one field of color signals in the field memory of the interfield interpolation circuit when the still image display mode is entered, and stores this stored color signal while the still image display mode is selected. Output the signal repeatedly.

In this way, the same luminance signal and color signal are repeatedly output to display a still image.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the overall configuration of the receiving device according to this embodiment.
Approximately 8 times depending on the satellite broadcast (BS) tuner section (not shown)
A television signal according to the MUSE system demodulated to the [NHZ] baseband is input to this receiving device.

The input television signal is applied to an analog/digital conversion circuit 1-, and after being converted into digital data by this analog/digital conversion circuit 1, it is applied to a de-emphasis circuit 2. The de-emphasis circuit 2 is
The inverse processing of the processing by the emphasis circuit of the transmission system is performed, and the de-emphasized signal is applied to the motion detection circuit 3, the interframe interpolation circuit 4, and the synchronization separation/timing generation circuit 5.

The motion detection circuit 3 detects motion of the television signal after de-emphasis processing and outputs a motion detection signal to each circuit as described below.

The synchronization separation/timing generation circuit 5 separates a synchronization signal from the de-emphasis-processed preview signal, and forms and outputs a control signal for controlling the operation timing of each circuit, which will be described later.

The interframe interpolation circuit 4 uses the frame memory 6 to insert one frame as data for dots that are compressed and have no data, since the still area of the received television signal is subjected to dot incretion by interframe offset sampling. Interpolate with previous data.

At this time, data of one frame before is moved in a predetermined direction based on a motion detection signal given from the motion detection circuit 3, and interpolated to prevent deterioration of the resolution of the panned and tilted screen. Further, the frame memory 6 is used to perform noise reduction processing.

The television signal output from the inter-frame interpolation circuit 4 is given to the low-pass filter circuit 7 to limit its band, and the sampling frequency is converted by the sampling frequency conversion circuit 8, and the next inter-field interpolation circuit B9 The data is provided to the interfield interpolation circuit 9 in a manner that facilitates processing.

The interfield interpolation circuit 9 has a detailed configuration shown in FIG. 2, and in modes other than the still image display mode (hereinafter referred to as normal display mode), the still area is interlaced with the driver 1 by interfield offset sampling. Therefore, the field memory 10 is used to interpolate data from one field before as data for dots with no data. At this time, the address for field memory 0 is controlled in accordance with the motion detection signal given from the motion detection circuit 3, the data position is corrected in the horizontal direction, and the panned screen is also treated as a static area to prevent deterioration of resolution. To prevent. This inter-field interpolated television signal is given to the adaptive mixing circuit 11.

The television signal subjected to interframe interpolation by the above-mentioned interframe interpolation circuit 4 is provided to an intrafield interpolation circuit 13 via a subsample switch circuit 12.

The sub-sample switch circuit 12 opens at the data timing of the interpolated dot between frames and replaces the data of that dot with "0", and closes for dot data for which there is data from the beginning and replaces that data. It is allowed to pass. The intra-field interpolation circuit 13 has a memory for several lines, and forms the data of the target dot I- (the target dot) by interpolating it from the data of several dots adjacent in the vertical and horizontal directions.

This is due to the line-to-line offset for moving areas of the image.
This is because the dot incline is applied by -, and cubic interpolation cannot be performed.

The television signal subjected to field interpolation in this manner is provided to the noise coring 14. The noise coring 14 removes components whose frequency is above a predetermined frequency and whose level is below a predetermined value as noise components, and converts the television signal after the noise removal into a static control circuit whose detailed configuration is shown in FIG. 2. is applied to the above-mentioned adaptive mixing circuit 11 via. In addition, stationary control time '#11
．． 5, without making any changes to the television signal from the noise coring 14 in the normal display mode.
This is applied to the adaptive mixing circuit 11-. On the other hand, in the still image display mode, a television signal with the same content is repeatedly output using the field 1 and memory 10.

A motion detection signal is supplied to the adaptive mixing circuit 11 from the motion detection circuit 3 . In the normal display mode, the adaptive mixing circuit 11 mixes the interpolated television signal as a still area given from the interfield interpolation circuit 9 and the still area given from the stillness control circuit 15 at a ratio corresponding to this motion detection signal. The interpolated television signal is mixed with the interpolated moving region, and the mixed television signal is supplied to the low frequency replacement circuit 16. On the other hand, in the still image display mode, 1-00% of the television signal from the still control circuit 15 is selected and output.

A television signal is supplied to the low frequency replacement circuit 16 from the de-emphasis circuit 2. The low frequency replacement circuit 16 is connected to the adaptive mixing circuit 11 when in the normal display mode.
The components of the television signal given from the de-emphasis circuit 2 of 4 [Mllz] or less are replaced with the components of the television signal given from the de-emphasis circuit 2 of 4 [Mllz] or less, and the replaced television signal is sent to the temporal filter circuit 1-7. give.

Here, the reason why the low frequency replacement port fY6.1.6 was provided is that in the region below 4 [Hzl] of the luminance signal, there is only folding for inter-frame offset sampling, so by replacing the frequency characteristic in the vertical direction. This is to flatten the curve and simplify the configuration of the vertical filters provided in the interpolation circuits 9 and 13 mentioned above.

The temporal filter 4B17 uses the frame memory 18 to perform processing to reduce changes in resolution at points of change between the still area and the moving area. The television signal from this temporal filter circuit 17 is given to a matrix circuit 1.9.

In the case of a television signal according to the MUSE system, the color signal is inserted into the horizontal blanking period, so when the color signal is displayed on a cathode ray tube (CRT) display device (not shown),
Since the signal during that horizontal blanking period becomes meaningless,
Temporal filter circuit 1-7 to 71 helix circuit 1
Even if the television signal for 9 includes a chrominance signal, that part is meaningless, and from this point on, the processing system from the global filter circuit 7 to the frame memory 18 constitutes a luminance signal processing system.

outputted from the above-mentioned interframe interpolation circuit 4], 2 The television signal is applied to a time base expansion circuit 20.

The time axis expansion circuit 20 extracts the color signal compressed to 1-/4 and inserted into the horizontal blanking period based on the control signal given from the synchronization separation/timing generation circuit 5, and multiplies the color signal by four times. The data is subjected to time axis expansion and provided to the interfield interpolation circuit 21.

The interfield interpolation circuit 21- has a detailed configuration shown in FIG. 2, and basically uses the field memory 22 to
In order to correspond to the inter-field dot incretion for the stationary area, the data of one field before is interpolated to the driver I for which there is no data. In this case, as in the luminance signal processing system, one image is formed from data between four fields through interframe interpolation and interfield interpolation, so the resolution can be increased. There will be. The inter-field interpolated color signal is given to the adaptive mixing circuit 23.

Furthermore, the television signal that has passed through the noise coring 14 described above is provided to a time axis expansion circuit 24 . The time axis expansion circuit 24 extracts the color signal inserted in the horizontal blanking period with the time axis compressed to 1/4 based on the control signal given from the synchronization separation timing generation circuit 5, and extracts the color signal inserted in the horizontal blanking period with the time axis compressed to 1/4. The time axis is expanded four times and applied to the field interpolation circuit 25.

This intra-field interpolation circuit 25 is provided in response to dot increase caused by line-to-line offset h of the color signal in the moving area, and uses built-in memory for several lines to perform interpolation in the vertical and horizontal directions. Dora l adjacent to
The data of the dot of interest is interpolated from the data, and the interpolated color signal is applied to the adaptive mixing circuit 23 via the static control I/roll circuit 26 whose detailed configuration is shown in FIG.

This still control I/roll circuit 26 is provided to realize still image display, and in the normal display mode, the adaptive mixing port B 23 does not change the color signal from the field interpolation circuit 25 in any way. give to On the other hand, in the still image display mode, the field memory 22 is used to repeatedly supply the same color signal to the adaptive mixing circuit 24f23.

The adaptive mixing circuit 23 is given a motion detection signal from the motion detection circuit 3, and in the normal display mode, the adaptive mixing circuit 23 receives the interfield interpolation circuit 21 which interpolates between fields in consideration of the static region. and the color signal from the stationary control I/roll circuit 26 interpolated within the field taking into account the moving area, are mixed at a ratio determined according to the motion detection signal and sent to the line-sequential decoding circuit 27. give. On the other hand, in still image display mode, still controller 1 to roll circuit 2
Select 100% of the color signals from 6.

The color signals according to the MUSE method are color difference signals R-Y and B-Y.
are inserted line-sequentially, and the line-sequential decoding circuit 27 separates and takes out these color difference signals and supplies them to the sampling frequency conversion circuit 28. The sampling frequency conversion circuit 28 is connected to the matrix circuit 18 from the temporal filter circuit 17 so that the conversion process by the matrix circuit 19 is performed well.
The sampling frequency of the incoming color difference signal is converted 152 to the same sampling frequency as the sampling frequency of the luminance signal given to .

The matrix circuit 19 performs matrix processing on the luminance signal given from the temporal filter circuit 17 and the color difference signal given from the sampling frequency conversion circuit 28, converting it into three primary color signals, and converts each primary color signal into corresponding digital/analog conversion. It is given to circuits 29R529G and 29B. Each of the digital/analog conversion circuits 29R to 29B converts a primary color signal made of a digital signal into an analog signal and outputs the analog signal to a display device (not shown).

Next, the interfield interpolation circuit, field memory, and still image control circuit that realize the still image display mode will be described in detail. Note that one interfield interpolation circuit, field memory 10 and still image control circuit 15 are provided in the luminance signal processing system, and one interfield interpolation circuit 21 and field memory 22 are provided in the color signal processing system.
Since these circuits 9, 10, and 15 provided in the luminance signal processing system will be explained here, these circuits 21 provided in the color signal processing system will be explained. The explanation of .22.26 will be omitted.

In FIG. 2, the television signal from the sampling frequency conversion circuit 8 is transferred to a switch circuit 40 having a two-power, one-output configuration that is switched by a sub-sampling clock signal for intra-field interpolation, and a still image display mode or a normal display. It is applied to a switch circuit 41 having a two-man power, one-output configuration that changes depending on the mode. In the normal display mode, this switch circuit 41 is connected to the stationary control circuit main body 4.
Switching signal SWI given from 2 (Fig. 3 (B))
The television signal provided from the sampling frequency conversion circuit 8 is selected based on the switching circuit 41, and the television signal via the switch circuit 41 is provided to the field memory 10 and delayed by the field period. It is applied to the other input terminal of the switch circuit 40. The switch circuit 40 selects the television signal delayed by one field and the directly input television signal using the sub-sampling clock signal, and adapts the television signal subjected to the intra-field interpolation process by this selection operation. Output to mixing circuit 11.

On the other hand, the television signal input from the noise coring 14 is switched to the switching signal SW2 given from the stationary control circuit main body 42 in the normal display mode.
According to FIG. 3(D), the signal is directly applied to the adaptive mixing circuit 11 via a switch circuit 43 having a two-man power, one-output configuration.

In addition to a configuration that performs such intra-field interpolation processing and outputs the television signal subjected to inter-field interpolation processing as it is, there is also a configuration that realizes still image display.

The television signal from the noise coring 14 is applied to a switch circuit 44 having a two-power, one-output configuration. This switch circuit 44 includes a stationary controller I to a roll circuit main body 42.
In the still image display mode, the television signal from the noise core song 18 is selected and sent to the switch circuit 41 only during the first 1-field in response to the switching signal 5W3 (FIG. 3(C)) given from the noise core song 18. give. When the switch circuit 41 enters the still image display mode, it immediately switches to the switch circuit 44 side in synchronization with the vertical synchronization signal VD (Fig. 3 (A)), and transmits the television signal from the noise coring 14 for one field. 1-
After the field period has elapsed, the switch circuit 44 is switched to input the output of the field memory 10.
The output television signal from this field memory 10 is selected and fed back to the field memory 1-0.

The output television signal from the field memory 10 is applied to a switch circuit 44 and also to a switch circuit 43. After the still image display mode is selected, the switch circuit 43 switches to select the television signal from the field memory 10 with a delay of 1° field, and selects the television signal from the field memory 10 to the adaptive mixing circuit 11. Output to.

In this way, when the still image display mode is entered, the television signal of the moving area processing system is stored in the field memory 10 for only one field in synchronization with the first vertical synchronization signal VD after that, and then the field memory 10 to the adaptive mixing circuit 11 and again to the field memory 10 for storage, so that the same television signal is output while the still image display mode is selected.

As a result, in the still image display mode, the adaptive mixing circuit 1-1 is provided with a television signal that has been inappropriately interpolated between fields and a television signal that has been interpolated within fields that repeats the same content. Therefore, in the still image display mode, the still control circuit main body 42 provides a signal instructing a mixing ratio in which the television signal via the switch circuit 43 is 100%, and transfers the television signal of the same content to the adaptive mixing circuit 11. , output from 1.

Furthermore, in the still image display mode, when reading a television signal from the field memory 1.0, the still control circuit main body 42 stops corrections due to panning, tilting, etc. by giving a readout address signal that is not related to the motion detection signal. I'll do what I do.

Furthermore, a replacement stop signal is given to the low frequency replacement circuit 16 to stop the low frequency replacement operation.

In this manner, in the still image display mode, a still image is displayed by providing the same luminance signal and color signal.

Therefore, according to the above-described embodiment, a still image display function can be realized even in a receiver for compressed band television signals according to the MUSE method.

For this reason, since the field memory 10.22 in the interfield interpolation circuit 9.21 is used, the added components are simpler and simpler than the addition of such functions.
It can be made small.

In the above-described embodiment, in order to repeatedly output the same signal from the field memories 10 and 22 in the still image display mode, the field memories 10 and 22 are
2 to the field memories 10 and 22.
, but the field memories 10 and 22
Writing may be stopped and reading may be repeated. In this case, field memories 10 and 22
Depending on the semiconductor device used, writing is stopped and only reading is repeated, so there is a risk that a large amount of noise may be mixed into the output signal over time.

[Effects of the Invention] As described above, according to the present invention, a still image display function can be realized by adding a small and simple configuration to a band compression television signal receiving device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a band compression television signal receiving device according to the present invention, FIG. 2 is a block diagram showing a detailed configuration of a four-axis portion for realizing still image display, and FIG.
The figure is a timing chart of each part of FIG. 2. 9.21-... Inter-field interpolation circuit, 10.22 Field memory, 13,25... Intra-field interpolation circuit, 15.26... Stationary control circuit, 41.4
3.44... Switch circuit, 42... Stationary control circuit main body.

Claims (1)

[Claims] Each of the luminance signal and chrominance signal processing systems includes an interfield interpolation circuit that uses a field memory to restore dot interlace by interfield offset sampling for a static area, and a line interpolation circuit for a moving area. In a band compression television signal receiving device that is equipped with an intra-field interpolation circuit that restores dot interlacing due to offset sampling, when a still image display mode is selected, the inter-field interpolation circuit of the luminance signal system In the field memory of
Luminance signal holding means for storing one field of luminance signals via the intra-field interpolation circuit and holding the luminance signals; and the inter-field interpolation circuit for color signal system when the still image display mode is selected. color signal holding means for storing the color signal of one field via the field interpolation circuit in the field memory and holding the color signal, and the luminance signal holding means and the color signal holding means hold the color signal. What is claimed is: 1. A receiver for compressed band television signals, characterized in that a still image is obtained from a signal obtained by