JP2570649B2 - Motion detection circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion detection circuit for a television signal, and more particularly, to motion information of a subject including a composite color television signal in which a color difference signal is modulated at a width carrier frequency and superimposed on a luminance signal. It relates to a circuit to be extracted.

[0002]

2. Description of the Related Art In a composite color television signal, the polarity of a carrier color signal is inverted for each scanning line, and is inverted between the current scanning line and the scanning line one frame before. Therefore, when extracting the motion information of the subject included in the television signal, since the difference signal between the simple frames includes the carrier color signal component, a significant difference signal appears even in a still image, and the correct motion information is obtained. Could not be extracted.

In the scanning line two frames before, the polarity of the carrier chrominance signal returns to the original, and as shown in Japanese Patent Application Laid-Open No. 61-70888, motion information can be extracted from the difference. FIG. 2 shows the configuration. In FIG.
Are input to the frame memory 2 having a capacity of two frames (1050H, H is a horizontal scanning cycle), and a signal two frames before the frame is obtained. When the difference between the two frames is calculated by the subtraction circuit 3 and the absolute value is calculated by the absolute value circuit 7, the motion information is obtained at the output terminal 6.

FIG. 2B shows another configuration, in which a signal two frames before the frame is obtained by continuously connected frame memories 8 and 9 having a capacity of one frame, and a subtraction circuit 3 calculates a difference between the two frames. . When the carrier chrominance signal band component is extracted by the band-pass filter (BPF) 13 and its absolute value is calculated by the absolute value circuit 14, the motion information of the carrier chrominance signal band is obtained.
On the other hand, the difference between the input and output of the frame memory 8 is calculated by the subtraction circuit 10, the low-frequency component is extracted by the low-pass filter (LPF) 11, and the absolute value is obtained by the absolute value circuit 12.
The carrier chrominance signal component is removed, and motion information of the luminance signal low frequency component is obtained. Therefore, these two signals are added to the addition circuit 16.
, Motion information is obtained at the output terminal 6.

[0005]

In the above-mentioned prior art, a still image is correctly determined to be "no motion". However, since a fast-moving subject uses a signal two frames before, no motion may be detected. There was a problem. FIG.
In the example of (b), the problem of the detection omission is reduced because the information of the difference between frames is also used. However, the motion of the subject having the same luminance signal level but only the hue different from the background is also not detected. Had occurred.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to accurately detect the movement of a fast-moving subject.
An object of the present invention is to provide a motion detection circuit for a composite color television signal in which detection omission does not occur.

[0007]

SUMMARY OF THE INVENTION The above-mentioned object is to provide one frame.
This is achieved by integrating a signal containing motion information obtained from the difference signal between two frames or two frames over a past finite field period.

[0008]

The movement of a part of a fast-moving subject which cannot be detected by the difference between one frame or two frames is detected in the past field or frame of the same pixel or its surrounding pixels. I have. Thus, 1 frame - arm or between 2 frame - obtaining a difference signal between beam and input to the motion information conversion circuit for converting it into motion information, integrating the output signal in the time spatial direction. As a result, if a motion is detected before a finite past field period, a significant signal is always obtained, and it is possible to prevent a detection omission that a motion of the subject cannot be detected.

[0009]

An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, an NTSC composite color television signal input to an input terminal 1 is input to a frame memory 2 having a capacity of two frames (1050H).
The subtraction circuit 3 calculates a difference between input and output of the frame memory 2, that is, a difference between two frames. On the other hand, after converting the difference signal between two frames into a signal representing motion by the motion information conversion circuit 4, integrating the motion information over the past finite frame period of the same pixel or a peripheral pixel by the integration circuit 5 in the time direction. Accordingly, desired accurate motion information can be output to the output terminal 6.

FIG. 3 shows the configuration of another embodiment of the present invention. In the figure, one frame capacity (525H)
A subtraction circuit 10 for subtracting a difference between frames and a difference between two frames by using two frame memories 8 and 9 connected in cascade.
Obtained by 3. The carrier chrominance signal component is removed from the frame difference signal by the LPF 11, its absolute value is taken by the absolute value circuit 12, and the read-only memory (ROM) 17 is used to read the motion information of the luminance signal low-frequency component corresponding to the magnitude of the motion. It is converted to M _1.
On the other hand, the difference signal between the two frames obtained by the subtraction circuit 3 is
Absolute value circuit 18, LPF 19, ROM 20, adder circuit 2
2 fluctuation by the motion information conversion circuit 4 consisting of 1 as the output of the ROM 20 - by the adding circuit 21 to obtain the original Nuisance motion information M ₂ to arm difference obtaining the sum of the motion information M ₁ previously obtained. This addition circuit 22 and 25, Fi - Rudomemori (262H) 23, a line memory (IH) 24, Fi in spatial direction of the integration circuit 5 when made from the coefficient circuit 26 - by integrating the field period unit output terminal 6 To obtain desired motion information.

FIG. 4 shows the configuration of still another embodiment of the present invention. In the figure, the luminance signal component of the NTSC signal input to the input terminal 1 is transmitted to the frame memory 27, the subtraction circuit 28, the LPF 29, the absolute value circuit 30, and the ROM 31 in the same manner as in the embodiment of FIG. motion information M ₁ is extracted from the low-frequency component of the beam between the differences. On the other hand, a band-pass filter (BPF) 32 and a demodulation circuit 3
2. After returning to the baseband color difference signal by 3
2 frames by the frame memory 2 with the frame capacity and the subtraction circuit 3
To obtain a difference signal between the signals. Next, the absolute value circuit 34 and the ROM 3
5 by the motion information M ₂ is extracted for the color difference signals, for selecting the larger of M _1, M ₂ with a maximum value circuit (MAX) 36. The selected motion information is a maximum value circuit (MAX) 37,
The coefficient circuit α, the field memory (262H) 39 and the line memory 40 constitute an integration circuit 5 in the time direction. The output terminal 6 outputs the maximum value of the motion information of the current scanning line and the upper and lower scanning lines one field before. Output to The resulting maximum value is alpha multiplied by the coefficient circuit 38 (0 <α <1) , Fi - is input to Rudomemori 39 finite Fi - Check <br /> while integration is achieved when over field period.

In the embodiment described with reference to FIG.
The difference signal between the two frames obtained in step (1) can be input to the absolute value circuit 18 after extracting the carrier color signal band by the BPF. If the ROMs 17 and 19 are shared and the outputs of the absolute value circuit 12 and the LPF 19 are added and then converted into motion information by the ROM, the required amount of the ROM can be reduced.

[0013] In the embodiment of FIG. 4, the finite Fi by subtracting a fixed number provided subtractor circuit instead of the coefficient α from the output of the MAX circuit 37 - it may implement spatial integration time over field period.

[0014] spatial direction of the integration circuit when the 3 and 4 examples are field cycle unit, with vertically spread also not time direction only. 2 frame - To rescue the motion information defects beam difference signal is also effective spatial integration effect time,
Those shown in the examples show good characteristics. Furthermore, in the embodiment it was the vertical spread, it is easy to vertically, the space-time integrating circuit having a spread in the horizontal directions.

[0015]

According to the present invention, in the motion detection using the difference between two frames of the NTSC color television signal, it is possible to prevent omission of motion detection, so that accurate motion information can be extracted, and There is an effect that the characteristics can be greatly improved by applying to various kinds of adaptive signal processing circuits.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a motion detection circuit according to the present invention.

FIG. 2 is a configuration diagram of a conventional motion detection circuit.

FIG. 3 is a configuration diagram of an embodiment of a motion detection circuit according to the present invention.

FIG. 4 is a configuration diagram of an embodiment of a motion detection circuit according to the present invention.

[Explanation of symbols]

1: input terminal, 2, 8, 9, 23, 24, 27, 39,
40 ... (frame, field, line) memory, 3,
10, 16, 21, 22, 25, 28 addition / subtraction circuit, 4 motion information conversion circuit, 5 integration circuit, 6 output terminal, 7, 12, 14, 18, 30, 34 ... absolute value circuit,
11, 13, 19, 29, 32 ... filters, 17, 2
0, 31, 35: read-only memory; 26, 38: coefficient circuit; 36, 37: maximum value circuit.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masato Sugiyama 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (72) Kenji Katsumata 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa (56) References JP-A-61-70888 (JP, A) JP-A-61-140291 (JP, A) JP-A-62-135094 (JP, A)

Claims (1)

(57) [Claims] In a motion detection circuit for extracting motion information of each pixel relating to the motion of an image, a difference signal between a signal of a pixel of interest and a signal of a pixel one frame before or a signal of a pixel of interest. A motion information conversion circuit for obtaining motion information of a pixel of interest from a difference signal between the signal and a signal of a pixel two frames before, or a difference signal between the two, and a field memory and a line memory; An integration circuit for integrating in the spatio-temporal direction using the motion information of the existing pixel and the motion information of the pixels of at least the upper and lower scanning lines of the previous field which has already been subjected to the integration processing in the spatio-temporal direction. Motion detection circuit.