JPH0123994B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a method for detecting motion information of an image from a video signal when converting a video signal based on interlaced scanning such as the NTSC system into a video signal using a progressive scanning system. Background technology Standard television system (NTSC system, SECAM system)
(PAL, PAL, etc.) is a composite signal in which the luminance signal and chrominance signal overlap on the frequency axis, so conventional frequency separation methods and comb wave separation methods may cause cross colors or the resolution of the luminance signal may deteriorate. The image quality deteriorates in the horizontal and vertical directions, making it impossible to obtain good image quality. In addition, these systems employ interlaced scanning, which causes phenomena such as line flicker interference, pairing interference, and the fact that scanning lines are viewed separately, degrading the image quality of the video. As a countermeasure for this, the luminance signal and color signal are separated based on the correlation between frames and between scanning lines.
It has been proposed to obtain interpolated signals by line interpolation and Hnoord interpolation, and to perform sequential scanning corresponding to one frame of interlaced scanning after supplementing the interpolated signals during one field period of interlaced scanning. Progressive scan conversion devices for converting images into progressive scan video signals have become popular, and these devices use motion detectors for the purpose of detecting image motion. However, the conventional motion detector is
As disclosed on page 19-24)
It is composed of a coring circuit, an isolated point removal circuit, a difference signal interpolation circuit, etc., and has the disadvantage of being expensive due to the complicated structure. In addition, in conventional motion detectors, it is necessary to extract and provide a luminance difference signal that indicates the difference between frames only in luminance signals from a composite video signal using an interlaced scanning method. This also has the disadvantage of complicating the structure and increasing the cost. DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and an object of the present invention is to provide an image motion information detection device that has a simple and inexpensive configuration and has a noise removal effect and a color signal component removal effect. belongs to. In order to achieve this objective, in the present invention,
By supplying a composite signal indicating the difference between frames in an interlaced scanning composite video signal in units of one scanning line, the central composite difference signal value at an odd number of sampling points adjacent to the scanning line can be calculated. A delay means for extracting, a first addition means for extracting composite difference signal values at mutually symmetrical positions on the left and right sides, and a first addition means for adding these, an output value of the addition means and an output value of the delay means. In contrast, the above-mentioned selection of coefficients is performed using a plurality of coefficient units that multiply each coefficient by a coefficient, and a second addition means that adds the output values of the coefficient units and detects the added value as image motion information. A low frequency filter having a characteristic of blocking color signal components is formed by this. Therefore, according to the present invention, it is possible to realize a motion detection means having a noise removal function and a color signal component removal function with a simple and inexpensive configuration, and without going through the signal processing process of YC separation as in the conventional case. Good motion information can be detected from a processing system for composite video signals obtained by receiving broadcasts. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be explained in detail with reference to figures showing examples. FIG. 1 is a block diagram showing a specific example of a motion information detector to which the present invention is applied. From an interlaced scanning composite video signal, a luminance signal Y _F separated from a field based on the correlation between frames, A chivalry signal Y _L separated from the scanning line in the same field based on the correlation between the scanning lines is given, and these are each subjected to phase adjustment by delay elements 1 and 2, and then , are multiplied by coefficients K _F and K _L by coefficient multipliers 3 and 4, and added by adder 5, and sent out as a luminance signal Y _R for sequential scanning. On the other hand, a composite difference signal ΔC indicating the difference between frames is given to the motion detector 6, and the detector 6 extracts a luminance difference signal component from the composite difference signal ΔC and detects a change in the luminance difference signal component. In order to generate and give this to the coefficient generator 7, the generator 7 sends out a signal indicating the coefficients K _F and K _L that change complementary to each other, and thereby the coefficients to be multiplied by the coefficient units 3 and 4 are Control. Therefore, when the image displayed by the video signal is a still image, the coefficient K _F is set large, when the image is a moving image, the coefficient K _L is set large, and when the image is in an intermediate state, the coefficient K F is set large. By selecting the ratio of both coefficients K _F and K _L , the luminance signal of the chivalry signal Y _R
The degree of dependence on Y _F and Y _L is determined. In other words, in the case of a still image, the brightness of each frame does not change, so the brightness signal Y _F can be used as the brightness signal Y _R , but in the case of a moving image, the brightness of each frame changes, so the brightness signal Y _F is used. Therefore, the luminance signal Y _L must be used as the luminance signal, and in an intermediate state between a still image and a moving image, the luminance signals Y _F and Y _L must be adjusted at a suitable ratio depending on the degree of movement. These operations are realized by the configuration shown in FIG. Note that the coefficient generator 7 has a plurality of threshold levels, and after determining the detected force level of the motion detector 6, sends a signal indicating the coefficients K _F and K _L according to the detected force level. things are used. In addition, the interpolated luminance signal is obtained by a separate circuit based on signals equivalent to the luminance signals Y _F and Y _L , and
It is temporarily stored in a memory or the like together with the luminance signal _YR , and then sent out at a scanning speed twice that of interlaced scanning, resulting in a progressive scanning luminance signal. However, the motion detector 6 and the coefficient generator 7 are
It can be used not only to control a circuit that obtains the luminance signal _YR , but also to control a circuit that obtains an interpolated luminance signal, a circuit that obtains a color signal for sequential scanning, and the like. FIG. 2 is a block diagram showing an embodiment of the present invention. A composite difference signal .DELTA.Cd indicating the difference between frames digitized in accordance with the sampling clock pulse is applied to the register 21a at the first stage. This register 21a stores and sends data with a time difference corresponding to one cycle of the sampling clock pulse. Further, similar registers 21b, 21c, and 21d are connected in cascade at the subsequent stages of this register 21a, and these registers 21a in even stages.
〜21d group is formed. Therefore, each register 2
Since there is a delay corresponding to one sampling period between the input and output of registers 1a to 21d, when the composite difference signal ΔCd is sequentially transmitted by registers 21a to 21d, the input of register 21a and the registers 21a to 21d The values of odd-numbered sampling points P ₁ to _{P 5} adjacent to each other on the scanning line are extracted from each output. That is, the composite difference signal value at the central sampling point _P3 among the sampling points _P1 to _P5 is here extracted from the output of the register 21b. Registers 21a, 21b therefore form delay means here. Also the central sampling point
Composite difference signal values at sampling points P ₂ , P ₄ and P ₁ , P ₅ at mutually symmetrical positions on the left and right with respect to P ₃ are extracted from the input and output of register 21a and the outputs of registers 21c and 21d. . These output values are summed in first adding means formed by adders 22 and 23, respectively. A register 21 representing this added value and the central sample point _P3
The output value of c is multiplied by an appropriate coefficient by coefficient multipliers 24 to 26, respectively. This coefficient unit 24~
The output values of 26 are added by an adder 27 forming a second adding means. And this adder 26
The added output value is sent as the detection power DO. Here, the coefficients to be multiplied by the coefficient units 24 to 26 are
If the coefficients are defined as K ₁ to _{K 3} and selected according to A or B in the following table, then when the frequency fs of the sampling clock pulse is four times the color subcarrier frequency fso, the coefficients K ₁ to K If ₃ is A, then Figure 3 A
When the coefficients K ₁ to _{K 3} are B, the transmission characteristics shown in FIG. 3B are obtained. This is done by paying attention to the frequency near the color subcarrier frequency fsc and thereafter, and creating a low-pass filter having characteristics that block the color signal component.

[Table] Therefore, the detection power DO includes the luminance difference signal value with the color signal component removed and each sampling point P ₁ ~
A value accumulated for _P5 is obtained, which indicates the motion information of the image, and the noise component in the luminance difference signal is removed by the integral action of accumulation, preventing false detection due to sudden noise. Ru. In addition, in FIG. 2, registers 21a to 2
Instead of 1d, a delay element such as an ultrasonic delay line or a CCD may be used. Also, each sampling point P ₁
The number and interval of ~ _P5 may be determined according to the maximum video area of the screen. It is also possible to configure the entire circuit with an analog circuit, and it is also possible to change the coefficients according to desired characteristics. In addition, although the embodiment has been explained using an example of 5 sample points, since a lot of information is concentrated at the center point as motion information in this type of video information, up to about 7 sample points can be used. If you do so, you can obtain practically sufficient results.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the use of the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a diagram showing pass characteristics. 21a to 21d...Register, 22, 23, 2
7...Adder, 24-26...Coefficient unit, ΔCd...
Composite difference signal, P ₁ to P ₅ ... sampling point, 21
a, 21b...delay means, 22, 23...first addition means, 27...second addition means.

Claims (1)

[Claims] 1 A device for detecting image motion information when converting an interlaced scanning composite video signal to a progressive scanning video signal, the apparatus comprising: a composite difference signal indicating a difference between frames in the interlaced scanning composite video signal; is supplied in units of one scanning line, so that screen 1
a delay means for extracting a central composite difference signal value at an odd number of sampling points adjacent to each other on a scanning line; a first adding means for extracting and adding these; and a first adding means for extracting and adding these; and a first adding means for extracting and adding these; Detection of motion information of an image, characterized by comprising a plurality of coefficient units for multiplying by a coefficient, and a second addition means for adding the output values of the coefficient units and extracting the added value as motion information of the image. Device.