JPS62258569A - Receiving device for band compression - Google Patents

Abstract

PURPOSE:To prevent deterioraton in the picture quality of a frozen picture by bringing substantially a memory for an inter-frame interpolation processing into the frozen state, using the signal stored in the memory so as to apply the inter-frame interpolation processing thereby a picture signal for still part. CONSTITUTION:An incoming input signal is controlled so as to be sent sequentially through the 2nd signal selection means 201, the 1st delay means 301, the 3rd signal selection means 202, the 2nd delay means 311, 312 and the 4th signal selection means 203, and a moving signal processing means is activated to expand a signal from a moving detection means 501 for a prescribed time in the time axis direction and to attenuate or stop the expansion. In freezing a picture by a control means, the 2nd and 4th signal selection means 201, 203 select the output of the 1st delay means 301 and the 3rd signal selection means 202 selects the output of the 2nd delay means 311,312.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a television signal receiving apparatus, and more particularly to an image signal receiving apparatus that performs band compression processing using multiple sub-Nyquist sampling. .

Conventional technology When transmitting a wideband image signal such as a high-definition television signal, the signal bandwidth is reduced by sub-Nyquist sampling [Television Society Technical Report [Satellite 1-channel transmission system for high-definition television J (
MUSE) TEBS95-2. VOJ7. /ni44]
is proposed.

This MUSE method applies an offset to the sampling phase between fields, frames, and lines, and transmits the image signal by performing processing such that the sampling phase goes around in 4 fields, that is, 2 frames. . Therefore, the receiving device is equipped with a frame memory to store image signals sequentially transmitted over four fields, and combines them to restore a high-definition television image. For the still image part, the above-mentioned inter-frame and inter-field offset subsampling processing and restoration processing of this signal are the basics, and for the moving image part, the inter-line offset subsampling processing and the restoration processing of this signal are the basics. MUS
A conventional example of an E-scheme television receiver will be described with reference to FIG.

The 16.2 MBPS signal supplied to the signal input terminal 100 is connected to the switch 200 and the field memory 300.3.
The signal is supplied to the interframe interpolation processing loop configured by 10. The signal delay time of this loop is set to approximately 562H for the field memory 300 forming the loop, and approximately 663H for the field memory 310, which is a total of 1 frame.
These field memories delay a 32.4 MBPS signal which has been subjected to interframe interpolation processing by a switch 200 that performs a selection operation approximately every 3Q nanoseconds, and sends the delayed signal to the next stage. The operation of the switch 200 is normally controlled by an interframe interpolation control signal among various control signals for the receiving device that are transmitted every field along with the image signal.Since this signal is a frame alternating signal, it is necessary to input the field memo IJK once. After the video signal has passed through this loop twice, it is replaced with a new video signal. In addition, the field memory 310 has a signal input terminal 1.
In response to the motion vector signal from 01, the image signal is configured to perform horizontal and vertical position correction on the image signal by changing its readout phase, in other words, the delay time.

The signal output by the interframe interpolation processing loop described above is supplied to the spatial interpolation processing circuit 400, the motion detection circuit 500, and the mixing circuit 700 through the conductor 210, and the spatial interpolation processing circuit 400 performs the interframe interpolation processing. The signal of the field is extracted from the received signal, subjected to a predetermined spatial interpolation process, and the moving image portion is supplied to the mixing circuit 700 via the conductor 410. The motion detection circuit 600 detects a moving part using image signal frame correlation, expands the detected motion signal in the time axis direction, that is, in the field or frame direction, by a temporal filter 600, and then passes the detected motion signal to the mixing circuit via a conductor 610. 700, and for the static part of the image, the signal from the conductor 210,
Regarding the moving part, the signal from the conductor 410 is controlled so that the mixing circuit element 00 selects the signal from the signal output terminal 1.
The restored high-definition television image is sent to 03.

Problems to be Solved by the Invention Since the above-mentioned band compression national signal receiving apparatus has a memory for interframe interpolation processing, this memo IJ k
Use it to reproduce images @! can be easily maintained in a frozen state. For example, by controlling the switch 200 to continuously select signals from the field memory 310,
By circulating the four-field image signal through the interframe interpolation loop, a signal that has been subjected to interframe interpolation processing on the conductor 210 can be obtained. However, in known receiving devices, the signals supplied to the motion detection circuit 600 are the same, so if motion detection is performed using frame correlation, the motion signal may not be output or may be incorrect. As a result, there is a practical problem in that the mixing circuit 700 cannot be controlled well. In addition, the spatial interpolation processing circuit 400 includes a conducting wire 210.
A signal that has been subjected to frame interpolation processing is supplied via the frame interpolation loop, and since this signal circulates through the frame interpolation loop, if only the signal of the relevant field is extracted, field skipping must be performed, and the field If signals are extracted for each field, spatial interpolation processing will be performed on the signals of two different fields.

Therefore, known receiving apparatuses have a problem in that when freezing an image, the image quality of moving parts deteriorates.

Means for Solving the Problems The receiving device according to the present invention has first and second delay means or storage means, and these first and second delay means
a first signal selection means coupled to the delay means to substantially perform interframe interpolation processing; and a second signal selection means whose output is coupled to the first delay means and one of the input terminals is coupled to the signal input terminal. , a third signal selection means disposed on the input side of the second delay means for selecting either one of the respective output signals of the first delay means or the second delay means, and an output signal to the other of the second signal selection means described above. are coupled to the first delay means or the second delay means.
interframe interpolation processing means including fourth signal selection means for selecting one of the output signals of the delay means;
a spatial interpolation processing means coupled to the delay means for performing spatial interpolation processing on the signal of a predetermined field; and a spatial interpolation processing means coupled to the first and second delay means for detecting a moving portion using frame correlation of the image. a motion signal processing means comprising a motion detection means to be detected and a third delay or storage means for expanding the output signal of the motion detection means in the time axis direction;
The mixing ratio is controlled by the output signal of the delay means, and the control means is coupled to the interframe interpolation processing means and the spatial interpolation means to perform image freeze control.

Operation The above-described frame interpolation processing means based on the present invention usually has an incoming input signal that is selected by the second signal selection means, the first delay means, the third signal selection means, the second delay means, and the fourth signal selection means. The motion signal processing means operates to stretch the signal from the motion detection means in the time axis direction for a predetermined period of time, and then attenuate or stop the stretching action. When the image is frozen by the control means, both the @2 and fourth signal selection means are controlled to select the output of the first delay means, and the third signal selection means selects the output of the second delay means.

Further, the motion signal processing means is controlled by the control means to hold the motion signal for the immediately previous field or frame, and the mixing means is controlled by the spatial interpolation processing means depending on the presence or absence of the motion signal supplied from the motion signal processing means or the amount thereof. and the interframe interpolation processing means, respectively, or a mixture thereof at a predetermined mixing ratio is sent out.

Embodiments Examples of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a receiving device according to the present invention. In FIG. 1, a switch 201, which is a second signal selection means, is connected between a signal input terminal 100 and memories 301 and 302, which constitute a first delay means. Normally, this switch 201 is controlled by a signal from the control signal input terminal 102 so as to successively select the incoming input signals supplied to the signal input terminal. The memo 17303 is coupled to the inputs of the memories 311 and 312 constituting the second delay means via the switch 202 which is the third signal selection means, and the memory 312 is connected to the inputs of the switches 202 and 203 which are the fourth signal selection means. A signal is supplied to one of the input terminals and also to a motion detection circuit 501 which uses frame correlation to detect moving parts of the image. These switches 202 and 203 are each controlled by a control signal from the terminal 102 similarly to the switch 201 described above, and normally the switch 202 connects the output of the memory 302 to the memory 311.
The switch 203 also supplies the output of the memory 312 to the other input of the switch 201 described above.

The switch 201 includes the motion detection circuit 50f, the spatial interpolation processing circuit 401, and the switch 2 which is the first signal selection means.
A signal is supplied to one input terminal of the memory 301, and the spatial interpolation processing circuit 401 receives approximately 1
A field-delayed signal is also provided and is further applied to terminal 102.
Normally, the control signal from conductor 420 determines its operation.
It is controlled so that spatial interpolation processing is performed on the image signal. The switch 202 supplies an image signal to the motion detection circuit 501 and the other input terminal of the switch 2040,
This switch 204 interpolates, or time multiplexes, two image signals having relatively different times for one frame, and supplies the interpolated image signals to the mixing circuit 700 as an image signal for a still portion. The above-mentioned motion detection circuit 501 uses the image signal supplied from the switch 201 as a reference, and detects between one frame with the signal from the switch 202 and between two frames with the signal from the memory 312. Both of these are configured so that image motion detection can be performed using frame correlation, but these can be selected as appropriate. A temporal filter (hereinafter abbreviated as such) 6o1, which is a motion signal processing means, expands the motion signal from the motion detection circuit 601 in the time direction, that is, in the field or frame direction. is controlled, typically in response to changes in the motion signal output by the motion detection circuit, to control the mixing ratio of the mixing circuit 700 via conductor 610. On the other hand, terminal 10
When the image is frozen by a control signal from switch 201.2, the receiving device according to the present invention described above
02 and 203 are the switch 203 and the memory 312, respectively.
, the memory 301.3o2 is controlled to successively select the output signal of the memo 1J302, the first image signal circular loop is created by the switches 203 and 201, and the memo 173
11, 312 and the switch 202 form a second image signal circulation loop. These switches 201 to 203
The image signals of the four fields received in advance of the field are stored in the memory 301.
2.311 and 312, and in the present invention, one frame from one field before and two fields before is stored in the first image signal circulation loop, and one frame from three fields before and four fields before Since each frame is retained by circulating the image signals in the second image signal circulation loop, the switch 204 for inter-frame interpolation basically only needs to perform signal selection operations sequentially. A motion vector signal is transmitted along with the signal, and an interframe interpolation phase control signal is also transmitted.If the phase of this signal is not sequential with respect to the four fields mentioned above, or if the phase of this signal is not sequential with respect to the field immediately before the field in question If the interpolation phase control signals are different, store this interframe interpolation phase control signal for one frame, and based on this, switch 204
It is only necessary to control the signal selection phase of . The temporal filter eo1 is controlled by a control signal from the terminal 102 in conjunction with the image freeze control so as to hold the motion signal for the field or one frame immediately preceding the field. For example, as shown in FIG. 2, a motion signal from the motion detection circuit 501 and a signal obtained by delaying this signal by one frame by the memo 17602 are supplied to the maximum value selection circuit 603, and the larger one of these is selected and the signal is 610, and the contents of this memory 602 are sent to terminal 1.
02, the maximum value selection circuit 603 is substantially configured to continuously select the motion signal from the memo I 7602 during the period of freezing the image. That is, the memo 1 placed by the motion detection circuit 6Q1 for the above-mentioned interframe interpolation process is substantially
If no motion signal is to be sent out by circulating the image signal through the respective loops including J301, 302 and 311°312, the temporal filter 601 may be constructed as in the specific example shown in FIG. In the case where a motion signal is sent out, the maximum value selection circuit 603 is made not to respond to this, and various other configurations are selected as appropriate. Further, in FIG. 3 shown as another configuration example, a three-man power maximum value selection circuit 604 is connected to a motion detection circuit 501 and a conductor 610.
A field memory 606, a coefficient unit 60
6 (K(1)) and the output of the memory 605 and the second feedback signal via the Sui Nochi 607 are used as the other two inputs of the aforementioned three-man power maximum value selection circuit 604. The switch 607 may be short-circuited only when freezing the image, and the configuration can be modified in various ways as in FIG. 2.

The spatial interpolation processing circuit 401 connects the terminal 10 during the freeze period.
The conductor 41 is controlled to successively select one of two image signals relatively different by one field supplied from the conductors 420 and 430 by two or more control signals.
An image signal for a moving part that has been subjected to spatial interpolation processing is transmitted. Also, in Figure 1, notes 17302 and 312
A switch 205 is disposed between the control signal input terminal 101 and the control signal input terminal 101, and the switch 205 is kept open during the image freeze period by a control signal from the terminal 102, thereby substantially prohibiting motion correction operations by the field memories 302 and 312. Therefore, it is effective to use this motion vector-based motion correction operation prohibition control together with the control of each section according to the present invention described above.

Effects of the Invention As described above, according to the receiving device of the present invention, the memory for interframe interpolation processing is substantially frozen, and the interframe interpolation processing is performed from the signals held in this memory to generate signals for static portions. At the same time, the spatial interpolation processing circuit continuously responds to the signal of a predetermined field to obtain the image signal for the moving part, and the output signal of the motion detection circuit using frame correlation is obtained. By substantially freezing the temporal filter that expands the field in the time direction, it is possible to select a part that can use signals of multiple fields and a part that requires a signal of a single field in a good manner or to set a predetermined ratio. This has the advantage that the image quality of the frozen image does not deteriorate.

In addition, in the above explanation, the mixing circuit is explained, but the conductor 61 is also
It is also possible to control whether interpolation is possible using a motion signal from 0, which has great industrial value.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a receiving device for band-compressed image signals according to an embodiment of the present invention, FIGS. 2 and 3 are block diagrams of a temporal filter used in the same device, and FIG. 4 is a conventional receiving device. FIG. 100.101.102,103... terminal, 2
01.202.203--...Switch, 3o1゜302.311,312...Memory, 401.
... Spatial interpolation processing circuit, 501 ... Motion detection circuit, 601 ... Temporal filter. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 ω/ Figure 4

Claims (1)

[Claims] A receiving device for an image signal subjected to band compression processing using multiple sub-Nyquist sampling, the receiving device comprising first and second delay means or storage means, a signal input terminal and an input of the first delay means or storage means. a first signal selection means for coupling the outputs and inputs of the first and second delay means or storage means, and another input of the first signal selection means; a third signal selection means for coupling the output of the second delay means or the storage means; the other input of each of the second and third signal selection means is coupled to the output of the second and first delay means, respectively; A control means for controlling the first to third signal selection means, and two signals coupled to the first delay means and each field being input relatively, and the control means extracts a signal of any field. spatial interpolation processing means for performing spatial interpolation processing; motion detection means coupled to the first and second delay means or storage means; and a third motion detection means controlled by the control means to expand the output of the motion detection means in the time direction. In a receiving device for a band compressed image signal having a motion signal processing means including a delay means or a storage means, when the control means freezes the image, the first delay means or storage means, the third signal selection means and the third signal selection means are used. The first to third signal selection means are controlled to form a first image signal circulation loop consisting of one signal selection means, a second image signal circulation loop consisting of a second delay means, and a second signal selection means, and a motion signal selection means is controlled. A receiving device for a band compressed image signal which is controlled to hold a motion signal of a processing means.