JP2863174B2 - Television receiver - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for receiving a multi-subsample transmission signal having a freeze function.

2. Description of the Related Art As one of methods for band-compressing a wideband video signal such as a high-quality television signal, a "MUSE system" has been proposed. The details are described in, for example, [NHK Technical Research, "Development of MUSE System", Vol. 39, No. 2, 1987]. This MU
In the SE system, a video signal is subjected to offset sub-sampling between fields, between frames, and between lines, and a process in which the sampling phase makes one cycle in four fields to perform band compression. Therefore, the receiving apparatus is provided with a frame memory for storing video signals transmitted sequentially over four fields and combining them to restore the original high-definition television signal. A conventional example of a MUSE television receiver will be described with reference to FIG.

The signal input terminal 10 is supplied with a digitized video signal. The still image processing circuit 11 performs inter-frame interpolation using video signals sequentially transmitted over four fields, and then performs inter-field interpolation to restore a still image and send it to the mixing circuit 14. On the other hand, the moving image processing circuit 12 performs field interpolation, restores a moving image, and sends it to the mixing circuit 14. The motion detection circuit 13 detects a motion portion using the frame correlation of the video signal, and supplies a motion control signal to the mixing circuit 14. In the mixing circuit 14, the output signal of the still image processing circuit 11 and the output signal of the moving image processing circuit 12 are mixed and restored at a predetermined ratio in pixel units in response to the motion control signal. Although the output signal of the mixing circuit 14 has been restored to a practically acceptable image quality, the temporal circuit 15
Performs processing in the time axis direction. The temporal circuit 15 includes a temporal operation circuit 16 and a frame memory 17. The output signal of the mixing circuit 14 is separated into low-frequency components by a two-dimensional spatial filter in the temporal operation circuit 16, and the high-frequency component is separated by a temporal low-pass filter composed of the temporal operation circuit 16 and the frame memory 17 in the time axis band. After the restriction, the high-definition television signal which is synthesized with the original low-frequency component by the temporal operation circuit 16 and restored at the output terminal 18 is obtained.

Problems to be Solved by the Invention However, the above-described receiving apparatus has a problem that an arbitrary display screen is displayed in a stationary state, that is, a so-called freeze display cannot be performed.

In view of the above, an object of the present invention is to provide a television receiver capable of performing a freeze display without a double image of a moving part, that is, a so-called multi-line blur.

Means for Solving the Problems The present invention provides a still image processing for performing a restoration process by inter-frame interpolation and inter-field interpolation by using a video signal sequentially transmitted over four fields in a receiver for a multiplex sub-sample transmission signal. A moving image processing circuit that performs a restoration process by inter-field interpolation using the video signal, a motion detection circuit that detects a motion portion using inter-frame correlation of the video signal, and a motion from the motion detection circuit. A mixing circuit that controls a mixing ratio between an output signal of the still image processing circuit and an output signal of the moving image processing circuit by a control signal, a temporal operation circuit that receives the output signal of the mixing circuit as an input signal, and a freeze signal input terminal. A switch 1 for selecting an output signal of the mixing circuit when a freeze signal arrives, and a field unit for storing the output signal of the switch 1 The still image processing part selects the signal of the previous field stored in the frame memory according to the obtained frame memory and the still image motion control signal, and selects the signal of the current field for the moving image part and the still area of the previous field to exit. Switch 2
The odd field indicates the signal of the current field stored in the frame memory, the even field indicates the switch 3 for selecting the output signal of the switch 2, and the switch 4 for selecting the output signal of the switch 3 when the freeze signal arrives.
A field memory for storing a motion control signal for the current field; a field memory for storing a motion control signal for the previous field; an output signal from the field memory for storing the motion control signal for the current field; and a motion control for the previous field. And an OR circuit for receiving an output signal of a field memory for storing a signal and outputting the still image motion control signal.

Operation The present invention stores the video signal of one frame of the current field (current field) and the previous field (previous field) in the frame memory by the freeze signal with the above-described configuration. A signal stored in units of fields obtains a freeze screen without multi-line blur by using a current field and a previous field for a still image portion and using a current field for a moving image portion of a current field and a previous field. .

Embodiment An embodiment of the present invention will be described below with reference to the drawings. For easy understanding, an outline of the operation will be first described with reference to FIG. In the following description, the current field is an odd field, and the previous field is an even field.

In FIG. 2, it is assumed that the moving object that was in A in the previous field has moved to A 'in the current field. If these two fields are simply combined and displayed on one screen, the moving part will be doubled and become a so-called multi-line blur,
The image becomes unnatural. (A). Therefore, in the present invention, the current field is displayed in the odd field for the still image portion, the previous field is displayed in the even field, and the A 'of the current field is displayed in the moving image portion for both the odd field and the even field. It is to try to prevent.

That is, in the odd field, the current field is displayed regardless of the still image portion and the moving image portion. In the even field, the still image portion displays the previous field. However, the moving image portion displays A 'of the current field instead of A of the previous field. Further, the still field of the previous field which exits by displaying the current field A 'instead of the previous field A is also displayed in the current field. In other words, the odd field indicates the current field of FIG. 2 (a). The still image portion of the even field displays a portion other than the “brow-eye” portion surrounded by the dotted line of the previous field in FIG. 2B, and the moving image portion is surrounded by the solid line of the current field in FIG. 2B. The displayed "eyebrows" portion is displayed to obtain an image without multi-line blur.

FIG. 1 is a block diagram showing a television receiver according to an embodiment of the present invention. The same operations as those in FIG. 4 showing the conventional example are denoted by the same reference numerals.
Description is omitted.

In FIG. 1, reference numerals 20 and 21 denote field memories for storing a motion control signal from the motion detecting circuit 13, 22 denotes an OR circuit for calculating the logical sum of the field memory 20 and the motion control signal stored in the field memory 21, and 23 to 26. Is a switch, 27 is a freeze signal input terminal for obtaining a freeze screen, and 30 and 31 are field memories constituting the frame memory 17.

The operation of the television receiver of the present embodiment configured as described above will be described below. First, the capture of the freeze screen will be described. Freeze signal input terminal 27
, The switches 23 and 26 are in the state shown by the solid line in FIG. In the conventional example, the video signal for one frame from the mixing circuit 14 restored by the operation described above is stored in the frame memory 17 via the switch 23. The frame memory 17 includes two field memories 30 and 31. The current field is stored in the field memory 30 and the previous field is stored in the field memory 31.

The other motion control signals for the current field and one frame of the previous field from the motion detection circuit 13 are stored in the field memory 20 for the motion control signal of the current field and the field memory 21 for the motion control signal of the previous field for one frame. A control signal is stored. Next, reading from the frame memory 17 will be described. For the video signal of the odd field, the output signal of the field memory 30 is obtained at the output terminal 18 via the switches 25 and 26. The switch 25 is switched for each field in synchronization with a vertical synchronizing signal (not shown), and at the time of an odd field, the connection is shown by a solid line in FIG. Next, in the even field, at this time, the switch 25 is connected as indicated by a dotted line in the figure. Switch 24
The video signal of the current field stored in the field memory 30 is supplied to one of the two input terminals, and the video signal of the previous field stored in the field memory 31 is supplied to the other input terminal.

The OR of the motion control signals of the current and previous fields stored in the field memories 20 and 21 is obtained by an OR circuit 22 to be a still image motion control signal indicating a motion portion of the current field and the previous field. At the output terminal of the switch 24 controlled by the still image motion control signal, the still portion obtains the signal of the previous field stored in the field memory 31 and the moving portion obtains the signal of the current field stored in the field memory 30. . The signal for the even field obtained at the output terminal of the switch 24 is sent to the output terminal 18 of the switch 26 via the switch 25 that switches every field.

FIG. 3 is a block diagram of a television receiver according to a second embodiment of the present invention. 1 in that a binary circuit 40 is provided at the input end of the field memory 20.

The original motion control signal is composed of several bits in order to perform fine control. However, in the case of the operation of switching the switch 24 as in the present invention, the purpose can be achieved by a binary operation. Therefore, in the present invention, a binarization circuit 40 for binarizing the motion control signal is provided at the input end of the field memory 20, and the field memories 20, 21 are reduced in capacity.

The binarization of the N-bit motion control signal is performed, for example, by providing an N-bit comparator and comparing it with a certain threshold value, or by using an N-bit input OR circuit to determine the presence or absence of the motion control signal, or It can be realized by a method using the MSB of a bit or the like. The operation in FIG. 3 is the same as the operation in FIG. 1 except for the above-described binarization of the motion control signal.

As described above, according to the present invention, a still image portion uses continuous two-field signals, and a moving image portion uses a single-field signal, and has good image quality without multi-line blur. Is obtained, and the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a block diagram of a television receiver according to one embodiment of the present invention, FIG. 2 is a schematic explanatory view of the operation of the embodiment, and FIG. 3 is a block diagram of a television receiver according to another embodiment of the present invention. FIG. 4 is a block diagram of a conventional television receiver. 20,21 …… Field memory, 22 …… OR circuit, 23-26…
... Switch, 30, 31 ... Field memory, 40 ... Binary circuit.

Continuation of the front page (72) Inventor Yuichi Ninomiya 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Research Institute (72) Inventor Seiichi Koshi 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting (56) References JP-A-62-104386 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 7/015

Claims (2)

(57) [Claims] 1. A still picture processing circuit for performing a restoration process by inter-frame interpolation and inter-field interpolation by using a video signal sequentially transmitted over four fields in a receiver for a multiplexed sub-sampled transmission signal; A moving image processing circuit that performs a restoration process by interpolating fields using a video signal; a motion detection circuit that detects a motion portion using inter-frame correlation of a video signal; and a still image processing process that uses a motion control signal from the motion detection circuit. A mixing circuit for controlling a mixing ratio between an output signal of the circuit and an output signal of the moving image processing circuit, a temporal operation circuit having an input signal of an output signal of the mixing circuit, and a freeze signal input terminal for a freeze signal. A switch 1 for selecting an output signal of the mixing circuit, and a frame memory configured for each field for storing the output signal of the switch 1; Still image processing part by the still picture motion control signal selects the signal of the previous field stored in the frame memory, the switch 2 still region of the previous field of the moving image portion and exit is to select a signal of the current field
The odd field indicates the signal of the current field stored in the frame memory, the even field indicates the switch 3 for selecting the output signal of the switch 2, and the switch 4 for selecting the output signal of the switch 3 when the freeze signal arrives.
A field memory for storing a motion control signal for the current field; a field memory for storing a motion control signal for the previous field; an output signal from the field memory for storing the motion control signal for the current field; and a motion control for the previous field. A television signal receiving device, comprising: an OR circuit that inputs an output signal of a field memory that stores a signal and outputs the still image motion control signal. 2. The television signal receiving apparatus according to claim 1, wherein the two field memories for storing the motion control signals are constituted by field memories for storing binarized motion control signals.