JPH0226915B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a motion detector that detects motion information of an image based on a video signal when converting a video signal based on interlaced scanning such as an 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 methods employ interlaced scanning, and based on this, line flicker interference,
Pairing interference and scanning lines being viewed separately have caused a phenomenon in which the image quality of the video is degraded. 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 that an interpolated signal is obtained by line interpolation and field interpolation, and in one field period of interlaced scanning, the interpolated signal is supplemented and sequential scanning corresponding to one frame of interlaced scanning is performed. Progressive scan converters have been developed to convert images into progressive scan video signals, 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, a vertical point removal circuit, a difference signal interpolation circuit, etc., and has the disadvantage of becoming 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 drawbacks of the conventional art, and has a simple and inexpensive configuration, and
The object of the present invention is to provide an image motion information detection device having a noise removal effect and a color signal component removal effect. In order to achieve this objective, in the present invention,
By supplying a composite difference signal indicating the difference between frames in an interlaced scanning composite video signal in units of one scanning line, the composite difference signal value at the center of an odd number of sampling points adjacent to each other on the scanning line can be calculated. Delay means to extract, composite difference signal values at mutually symmetrical positions on the left and right with respect to the delay means, and composites of sampling points corresponding to the center on each scanning line located before and after the scanning line. a first addition means for extracting the difference signal value and adding these;
The output value of the first addition means and the output value of the delay means are each multiplied by a coefficient and then added. Along with detecting information,
By selecting the coefficients, a low frequency filter having a characteristic of blocking color signal components is formed. Therefore, according to the present invention, it is possible to realize a motion detector 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 image motion information can be detected from a processing system for composite video signals obtained by receiving broadcasts. [BEST MODE FOR CARRYING OUT THE INVENTION] The details of the present invention will be explained below with reference to figures showing examples. _FIG . 1 is a block diagram showing an example of the use of an embodiment of the motion detector according to the present invention, in which a luminance signal Y , and a luminance signal Y _L separated from the scanning line in the same field based on the correlation between the scanning lines.
After undergoing phase adjustment, the signals 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. , and in order to supply it to the coefficient generator 7, the generator 7 sends out signals indicating the coefficients K _F and K _L that vary in a complementary manner. 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 luminance 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. This will give an inaccurate result, so the luminance signal Y _L is replaced by the luminance signal Y _R
In the intermediate state between a still image and a moving image, it is required to mix the luminance signals _YF and _YL at a suitable ratio depending on the degree of movement, and these operations are performed as shown in Figure 1. This is achieved through the configuration. 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 from a separate answer based on signals equivalent to the luminance signals Y _F and Y _L ,
It is temporarily stored in a memory or the like together with the luminance signal _YR , and then sent out at twice the scanning speed 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 illustrating an embodiment of the present invention, in which the data between frames digitized in response to the sampling clock pulse is input to the input of a register 21 which provides a delay corresponding to one cycle of the sampling clock pulse. A composite difference signal ΔC _d is given that indicates the difference between . In addition, a memory 22 provides a delay corresponding to a period of one scanning line of interlaced scanning (hereinafter referred to as H).
via register 2, which is equivalent to register 21 described above.
3a and 23b are also given the composite difference signal ΔC _d . The output of the register 23a is connected to a memory 24 similar to the memory 22, and a composite difference signal ΔC _d delayed by 1H plus one cycle of the sampling clock pulse is applied to the memory 24. register 2
1 and 23b, and memories 22 and 24
Each output value is added to an adder 2 forming a first adding means.
5 is added. Then, after multiplying the output of the register 23a and the output of this adder 25 by coefficients α and β using coefficient multipliers 26 and 27, respectively,
An adder 28 forming the second adding means obtains an added value and sends it out as the detection power DO.
Therefore, the memory 22 and the register 23a form delay means for determining the center point of the sample image, which will be described later. Therefore, there is a gap between each input and output of the memories 22 and 24.
A time difference of 1H is generated, and registers 21, 23a,
There is a time difference equivalent to one sampling period between the input and output of each memory 22, 23b.
4. Output of registers 21, 23a, 23b as P ₁
~ _P5 , each sampling point _P1 ~ _P5 of the sample image in FIG. ₃ showing scanning lines _S1 ~S3
It corresponds to Therefore, register 2
1 and the input of the memory 22 correspond to the reference point P ₀ when viewed from the sample images on the scanning lines S ₁ to S ₃ . Further, the output of the register 23a includes odd number sampling points P2 _{to P4 adjacent} to each other on the scanning line _S2 .
In the middle, a composite difference signal value at the central sampling point _P3 is obtained. The added value by the adder 25 is the composite difference signal value at the sampling points P ₂ and P ₄ at mutually symmetrical positions on the left and right with respect to the central sampling point P ₃ , and the previous position of the scanning line S ₂ . and sampling points P ₁ , corresponding to the central sampling point P ₃ on each scanning line S ₁ , S ₃ located at the rear;
It becomes the sum value with each composite difference signal value of _P5 . the result,
The detection output DO is multiplied by coefficients α and β and then added, so this is
It shows the motion information of the integrated sampling image in the horizontal and vertical directions centered on the sampling point _P3 . Here, the coefficients α and β to be multiplied by the coefficient multipliers 26 and 27 are selected as shown in A or B in Table 1,
When the frequency f _s of the sampling clock pulse is set to four times the color subcarrier frequency f _sc , in case A, the passage characteristic shown in Fig. 4A is obtained, and in case B, the passage characteristic shown in Fig. 4A is obtained.
The pass characteristic shown in Figure B is obtained. Therefore, if attention is paid to the vicinity of the color subcarrier frequency _fsc and beyond, a low frequency filter having characteristics that blocks the color signal component is formed.

[Table] As a result, the detection power DO includes the luminance difference signal value from which the color signal component has been removed at each sampling point P ₁ to _{P 5}
An accumulated value is obtained, which indicates the motion information of the image, and the noise component in the luminance difference signal is reduced due to the integral action of the accumulation, thereby preventing false detection due to sudden noise. Further, since sampling points are arranged not only in the horizontal direction, which is visually sensitive to movement, but also in the vertical direction, it is possible to accurately detect image movement information. FIG. 5 is a block diagram in which the number of sampling points is increased to 5 instead of 3 in the example of FIG. 2, and registers 51a and 51b that provide a delay of one sampling period are connected in series. A digitized composite difference signal ΔC _d is applied to the input side of this. Also, a memory 52 that provides a delay of 1H, and registers 53a and 53b similar to the above-mentioned registers 51a and 51b.
A composite difference signal ΔC _d is also given to the series circuit of the memory 52, and the output of the memory 52
A composite difference signal ΔC _d is connected to a series circuit consisting of registers 55a to 55d similar to the registers 51a and 51b described above, and is delayed by 1H.
is giving. The output of the register 55b is connected to a series circuit of memories 56a and 56b similar to the memory 52. Further, the output values of the registers 53b, 55a, 55c and the memory 56a are added by an adder 57 forming a part of the first adding means. On the other hand, each output value of the registers 51b, 55d and memories 54, 56b is sent to an adder 58 forming a part of the first adding means.
is added by The output of the register 55b and the outputs of the adders 57 and 58 forming the first addition means are converted into coefficients α,
They are each multiplied by β and γ and added by an adder 62 forming a second adding means. The output value of this adder 62 is sent out as the detection power DO. Therefore, if each output is defined as P ₁ to P ₉ as in Figs. 2 and 3, the sampling points of the sampling image in Fig. 6 showing scanning lines S ₁ to _{S 5}
It corresponds to P ₁ to _{P 9} , and the register 51a
The input of the memory 52 corresponds to the reference point P ₀ when viewed from the sampling images on the scanning lines S ₁ to _{S 5} . Therefore, sampling point P ₅ corresponds to sampling point P ₃ in FIG. 3, and sampling point P ₄ ,
P ₆ , P ₂ , and P ₈ are the sampling points P ₂ , P ₄ , and
This corresponds to P ₁ and P ₅ . The coefficient multipliers 59 and 60 correspond to the coefficient multipliers _{26 and 27} in FIG _. After the composite difference signal values at are added, the coefficient multiplier 6
The coefficient γ is multiplied by 1 and this is added in an adder 62 forming the second adding means. Here, the coefficients α, β, and γ are A or B in Table 2.
If the selection is made as shown in FIG. 7A or B in FIG. That is, in the case of Table 2 A, the passage characteristic as shown in FIG. 7A is obtained, and in the case of Table B, the passage characteristic as shown in FIG. 7B is obtained, and the same result as that in FIG. 2 is obtained.

[Table] According to the configuration shown in FIG. 5, the sampling points are distributed over scanning lines S ₁ to _{S 5} as shown in the sampling image shown in FIG. 6, so compared to the configuration shown in FIG. Motion information of a wider range of images is detected, improving the accuracy of the detection situation. In FIGS. 2 and 5, a delay element such as an ultrasonic delay line or CCD may be used instead of the register and memory, and the number and interval of each sampling point may be determined according to the maximum moving image area of the screen. Of course, it would be fine if it were determined. In addition, it is optional to construct the entire circuit using analog circuits, and various modifications are possible, such as selecting coefficients according to desired characteristics.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the use of an embodiment of a motion detector according to the present invention, FIG. 2 is a block diagram showing an embodiment circuit of the present invention, and FIG. A diagram showing an example of a sampling image, FIG. 4 is a diagram showing the pass characteristic in the embodiment circuit of FIG. 2, FIG. 5 is a block diagram showing another embodiment circuit of the present invention, and FIG. 6 is a diagram of FIG. FIG. 7 shows an example of a sampling image on a scanning line corresponding to
This figure is a diagram showing the pass characteristics in the circuit of the embodiment shown in FIG. 6...Motion detector, 21, 23a, 23b, 5
1a, 51b, 53a, 53b, 55a-55d
...Register, 22, 24, 52, 54, 56
a, 56b...Memory, 25, 28, 57, 5
8, 62... Adder, 26, 27, 59-61...
... Coefficient unit, ΔC _d ... Composite difference signal, S ₁ to _{S 5} ... Scanning line, P ₁ to _{P 9} ... Sampling point, 22, 23a,
54, 55a, 55b...Delay means, 25, 5
7, 58...first addition means, 28, 62...second addition means.

Claims (1)

[Claims] 1 A motion detector for detecting image motion information when converting an interlaced scanning composite video signal into a progressive scanning video signal, and a motion detector that detects the difference between frames in the interlaced scanning composite video signal. By supplying one composite difference signal in units of one scanning line, a delay of one sampling period, which is one period of the sampling clock pulse, is given to the first composite difference signal to generate a second composite difference signal. A first register 21 for outputting, and a first memory for applying a delay of one scanning line period, which is a period for one scanning line of interlaced scanning, to the first composite difference signal and outputting a third composite difference signal. 22
and a second circuit that applies a delay of one sampling period to the third composite difference signal to output a fourth composite difference signal.
a fourth register 23b that applies a delay of one sampling period to the fourth composite difference signal to output a fifth composite difference signal; 6th signal given
a second memory 24 that outputs a composite difference signal of , a first addition means 25 that adds the second, third, fifth, and sixth composite difference signals, and an output value of the first addition means and It is characterized by comprising a second addition means 28 that multiplies each of the fourth composite difference signal values by a coefficient and then adds them, and extracts the added value of the second addition means as motion information of the image. motion detector.