JPH0258492A - Method for detecting movement information for composite color television signal - Google Patents

Abstract

PURPOSE:To improve detecting accuracy by using not only the low frequency component of a differential signal but also a high frequency component as the information of movement when a color signal component extracted by an inter-line comb-line filter is small. CONSTITUTION:A differential signal C between one frame is generated with a subtracting circuit 2 from a compound color television signal (a) delayed for the equivalent of one frame and a compound color television signal (b). The one of the differential signal C extracts a signal (d) of a low frequency component by an LPF circuit 3, and the other constitutes a differential signal (e) delay-adjusted by a delay circuit 8. On the other hand, at the comb-line filter 6, a color signal component is extracted, the level of the color signal component is detected by a level judging circuit 7, and when the color signal component is small, the differential signal (e) between one frame, when the color signal component is large, the low frequency component (d) of the differential signal between one frame is used respectively for the detection of movement information. Thus, the detecting accuracy of the movement information can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting motion information in a composite color television signal.

[Conventional technology]

IDT that receives composite color television signals with high image quality
V
In improved Definition TV), so-called motion-adaptive Y
C-separated signal processing achieves separation characteristics with less crosstalk components.

In order to perform the motion-adaptive signal processing described above, motion information is required. Therefore, as a knob method for detecting motion information from a composite color television signal, it is known to use, for example, a low frequency component of a difference signal between two frames or a difference signal between one frame.

[Problems to be Solved by the Invention] The above-mentioned conventional technology does not take into account the detection of motion in the vicinity of 15 Hz in the 9-time frequency component, and in response to this type of motion, the image may be erroneously stopped even though it is a moving image. Since the image is determined to be an image, there is a problem in that the motion adaptive processing malfunctions, resulting in image quality deterioration.

The object of the present invention is to provide the above-mentioned method in which motion information can be detected even for motions whose time-frequency components are around 15 Hz.
An object of the present invention is to provide a motion detection method for a composite color television signal.

[Means to solve the problem]

To achieve the above object, a difference signal between one frame of a composite color television signal is provided.

When the color signal component extracted by the line-to-line comb filter is small, a motion detection method that uses not only the low-frequency component of the difference signal but also the high-frequency component as motion information improves the detection accuracy for motion around a 1-hour frequency of 15 Hz. It is an improved version of

[Effect]

In the N'FS CJj type composite color television signal, the one-color signal C is superimposed on the luminance signal Y in a phase-inverted relationship for each line and frame.

Therefore, in the three-dimensional frequency domain of two hours horizontally and vertically,
The signal spectrum has characteristics as shown in FIG. In the figure, μ, shi, and f are the horizontal frequencies (H
z), vertical frequency (cph)+temporal frequency (Hz).

On the other hand, in the conventional motion detection method that utilizes the low frequency component of the difference signal between two frames of a composite color television signal or the difference signal between one frame, in the three-dimensional frequency domain, the diagonal line shown in FIG. The area is detected as movement information.

Here, (a) and (b) in the same figure show a difference signal between two frames, and (c) and (d) in the same figure show a low frequency component between one frame.

Therefore, the high frequency component of the luminance signal (for example μ>2MHz
) moves at a temporal frequency near L 5H2, it becomes impossible to detect movement information using the prior art.

Now, in the conventional technology, the low frequency component of the difference signal between one frame is used to detect the a difference signal because this high frequency component includes the component of the color signal C as well as the motion information of the luminance signal. It is.

Therefore, if there is no color signal C component in this high frequency component, this signal corresponds to motion information of the luminance signal and can be used for motion detection.

Now, the presence or absence of the color signal C component can be detected using, for example, an interline comb filter having characteristics as shown in FIG.

Therefore, if the component of the one-color signal C is not detected or is relatively small, the high-frequency component of the difference signal between one frame can also be used to detect motion information.
It is possible to improve the accuracy of motion detection and reduce malfunctions such as failure to detect motion information.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The subtraction circuit 2 calculates the difference between the composite color television signal a and the composite color television signal delayed by one frame by the one-frame delay circuit 1, and generates a one-frame difference signal C. do. One of the differential signals C is processed by the LPF circuit 3, for example, μ<
The other one, which extracts the signal d of the low frequency component of 2 MHz, forms a difference signal e whose delay is adjusted by a delay gate.

On the other hand, the line comb filter 6 extracts color signal components from the composite color television signal with the characteristics shown in FIG. 4, for example. The level of the extracted color signal component is detected by the level determination circuit 7, and for example, if the signal level is Δ'r
If it is within the range of h to ΔTh, it is determined that there is no color signal component, and if it exceeds this range, it is determined that there is a color signal component.

In the selection circuit 4, when the level determination circuit 7 determines that the color signal component is present, the signal d, i.e., the low frequency component of the difference signal between one frame, 1 when the color signal component is determined to be absent. is the signal e, that is, 1 including the high frequency component.
The inter-frame difference number 4rj is selected as the output signal.

Then, the output signal of the selection circuit 4 is subjected to absolute value quantization by an absolute value quantization circuit 5, for example, with a characteristic as shown in FIG. 4(b) to generate motion information.

Note that the level determination circuit 7 preferably performs processing such as spatial smoothing between a plurality of pixels to eliminate the influence of erroneous determination due to noise or the like.

Next, FIG. 5 shows an embodiment in which the present invention is applied to YC separation signal processing of a composite color television signal.

This embodiment shows a case in which detection of motion information according to the present invention and detection of motion information using a difference signal between two frames are used together.

For the composite color television signal, the frame comb filter 9 extracts a color signal component CF corresponding to a still image by performing interframe calculations. - side, horizontal BPF circuit 1
0. By combining the line comb filters 11, a color signal component Cs corresponding to a moving image is extracted. In this case, the edge detection circuit 12 detects the horizontal edge area, and the selection circuit 13 selects the horizontal 13 )) F
Extraction of the color 4B component with less deterioration is realized by controlling to extract the signal component of the circuit.

These extracted Cs + Cs signals are sent to the weighting circuit 20
Motion information coefficient k, which will be described later in each case.

The color signal component C is subtracted by the subtraction circuit 23 from the composite color television signal which has been delayed and adjusted by the addition circuit 21 and the addition circuit 22 to obtain the luminance signal component Y.
Extract.

Now, motion information is detected from the difference signal between one frame and between two frames of the composite color television signal.

The motion detection circuit 14 based on the difference between one frame
By the configuration shown in the figure.

Detects motion information. On the other hand, a two-frame difference signal detection circuit 15 detects a difference signal between two frames, and an absolute value quantization circuit 16 detects absolute value quantized motion information.

The MAX selection circuit 17 selects the maximum of both, and the multidimensional smoothing circuit 18 selects the horizontal one.

Smoothing is performed in a vertical two-dimensional space or in a three-dimensional space that also includes time. Then, the motion information coefficient is 1−
In the determination circuit 19, according to the smoothed motion information,
A motion coefficient between 1 for a completely still image and 0 for a moving image with large motion is determined.

Note that the motion information detected by this embodiment is as follows.

In addition to YC separation signal processing, the present invention can also be applied to signal processing such as conversion from interlaced scanning to sequential scanning using scanning line interpolation.

〔Effect of the invention〕

According to the present invention, since the detection accuracy of motion information can be improved, there is an effect of reducing image quality deterioration due to detection omission.

In this embodiment, the operation was explained using an NTSC television signal as an example of a composite color television signal. :Extended Def
It is clear that this method is also effective for initiation TV).

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing an embodiment of motion information detection of the present invention and a characteristic diagram of an absolute value quantization circuit, and FIG.
FIG. 3 is a three-dimensional signal spectrum diagram of a TSC composite color television signal, and FIG. 4 is an explanatory diagram of a motion information detection area according to a conventional method. A characteristic diagram showing an example of the characteristics of a line comb filter, and FIG. 5 is a circuit block diagram of an embodiment in which the present invention is applied to yc separation signal processing. 1...1 frame delay circuit, 2...subtraction circuit, 3-
°. LPF circuit, 4... Selection circuit, 5... Absolute value quantization circuit, 6... Line comb filter, 7... Level determination circuit, 8... Delay circuit, 9... Frame comb type filter. 10...Horizontal BPF, 11...Line comb filter. 12... Edge detection circuit, 13... Selection circuit, 14
...Motion detection circuit based on 1-frame difference, 1-2.
...Difference signal detection circuit between two frames, 16...Absolute value quantization circuit, 17...MAX selection circuit, 18...Multidimensional smoothing circuit, 19...Motion information coefficient, 1- Decision circuit, 2o... Weighting circuit, 21... Addition circuit, 2
2...Delay circuit, 23...Subtraction circuit. 31 Σ inscription + b) ke = 11 children, 50 A3, 1 Li Qi'
j Lord) Tarihiro Power 4z Tongue Musu 2! (d) (b) 11, N flat:, 4 table bottles! iria, cloth, department; 1. 'lZ' eup, l

Claims (1)

[Claims] 1. Means for extracting a difference signal between one frame of a composite color television signal and a low frequency component of the difference signal;
It has means for extracting a color signal component using a line comb filter, and when the color signal component is small, it is a difference signal between one frame, and when the color signal component is large, it is a low frequency component of the difference signal between one frame. A method for detecting motion information of a composite color television signal, the method comprising: detecting motion information of a composite color television signal.