JPH067651Y2 - Image motion detection circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an image motion detection circuit used for scan conversion of IDTV and EDTV.

[Conventional technology]

Conventionally, for example, in IDTV, it has been proposed to scan-interlace (interlace) video signals, that is, the current NTSC video signals to be converted into progressive scan (non-interlace) video signals to improve image quality. ing.

When performing the above-described scan conversion, it is described in, for example, Japanese Patent Laid-Open No. 58-130685 (H ₀₄ N 9/02), Proceedings of the 1986 National Conference of the Television Society, page 51, etc. In addition, the motion of the video signal is digitally detected from the inter-frame difference of the interlaced video signal to be scan converted, and a signal of motion information corresponding to the motion amount is obtained, and based on the signal, the motion amount is determined according to the motion amount Interpolation data for scanning lines must be generated by selectively performing interfield interpolation and intrafield interpolation.

By the way, a conventional image motion detecting device for digitally detecting the motion is configured as shown in FIG.

The interlaced video signal, which is an NTSC video signal, for example, is converted into digital data by a digital conversion unit (not shown), and is input to the frame memory unit (2) via the input terminal (1).

At this time, the memory unit (2) delays the input digital data by one or more frames and outputs the input digital data.
The Da and the frame-delayed digital data Db are output to the interframe difference calculation unit (3).

Then, based on the level difference between the input data by the calculation unit (3), the inter-frame difference of the interlaced video signal is calculated in pixel units or in block units of a plurality of pixels, and from the calculation unit (3). The difference data at the calculated level of the difference between frames is output to the preprocessing circuit unit (4).

Further, the circuit section (4) digitally performs preprocessing such as an absolute value conversion of the input difference data and a low-pass filter for noise removal, and the circuit section (4) moves the motion determination section.
At (5), detection data obtained by converting the difference data into an absolute value, that is, motion detection data in pixel units or block units is output.

By the way, the determination unit (5) is composed of a digital comparator and the like, and in order to determine the amount of motion with a predetermined determination characteristic, determination reference data for motion detection of a plurality of level stages is set.

The determination unit (5) compares the input motion detection data with the determination reference data to determine the amount of motion, and the data indicating the level of the amount of motion is used as the motion information signal Dc in the post-processing circuit unit.
Output to (6).

Furthermore, post-processing such as low-pass filter processing for final noise removal is digitally performed by the circuit section (6), and the post-processed signal Dc is output from the circuit section (6) to the output terminal (7).
Is output.

Actually, the circuit unit (4) also has a coring function for adjusting the level of the difference data based on the sync edge of the video signal, and when the difference data is obtained from the inter-frame difference between one frame, By the calculation unit (3), for example
The frame difference is calculated by the method described in Japanese Patent Application Laid-Open No. 0-57794 (H ₀₄ N 11/20) and Japanese Patent Laid-Open No. 58-130685.

[Problems to be solved by the device]

By the way, in the conventional motion detecting circuit of this type, since the characteristic of the determining unit (5) is fixed to a predetermined characteristic, the detection characteristic of the moving portion is fixed.

Therefore, for example, when the received electric field strength is lower than the standard strength, the noise level for the video signal increases, and the noise of the video signal increases, almost all of the screen is determined to be a moving part, and Even if the same video signal of
There is a problem that proper motion interpolation cannot be performed based on Dc.

On the other hand, the best motion compensation differs depending on whether the screen content of the video signal has many moving parts and vice versa.Therefore, the detection characteristics should be varied according to the screen content, in addition to the magnitude of the noise described above. However, in the case of the conventional detection circuit, the signal Dc does not change depending on the screen content,
There is also a problem that it cannot be detected with an appropriate characteristic according to the screen content.

In order to vary the detection characteristic, for example, the determination unit (5)
It is conceivable to set reference levels for multiple judgment characteristics in and to switch the characteristics manually by switching the switch, but in this case, complicated operation is required and
Proper switching is difficult and impractical.

The present invention aims to automatically change the detection characteristics of a moving part according to the judgment result of the motion judging section, and further, the detection standard to be considered as a moving part is automatically strict according to the magnitude of noise. , The purpose is to change the detection criteria to be considered as a moving part automatically and gently according to the contents of the screen.

[Means for Solving the Problems]

In order to solve the above problems, the image motion detection circuit of the present invention digitally detects the motion of the video signal from the inter-frame difference of the interlaced scanning video signal, and outputs the signal of the motion information of the video signal. In the image motion detection circuit, a digital conversion unit that digitally converts the video signal, an inter-frame difference calculation unit that calculates the inter-frame difference of output data of the conversion unit in pixel units or block units, and outputs difference data. A motion determination unit that compares the motion detection data obtained by converting the difference data into an absolute value with determination reference data for motion detection to determine a motion amount, and outputs the motion amount data as a signal of the motion information; A counting unit that repeatedly counts the amount of the motion information signal in a predetermined field cycle, and the determination reference data according to the count data of the counting unit,
And a detection control means for varying the input data of the determination unit or the output data of the determination unit and varying the determination movement amount according to the count data.

When the detection characteristic is varied depending on the magnitude of noise, an inverse proportional control means for varying the determination motion amount according to the magnitude of the count data may be provided as the detection control means.

Further, when the detection characteristic is varied depending on the screen content, a proportional control means for varying the determination movement amount according to the magnitude of the count data may be provided as the detection control means.

[Action]

The image motion detection circuit configured as described above, based on the count of the counting unit, repeatedly counts the determination result of the predetermined motion amount or more of the motion determination unit in a predetermined field cycle and controls the detection control unit. Based on the magnitude of the count data of the counting unit, the determination movement amount is changed, and the detection reference regarded as a moving portion is automatically changed according to the count data.

Then, depending on whether the noise is large or small,
The determination movement amount may be decreased or increased according to the smallness, and the detection reference may be changed strictly according to the size of the counting data.

Depending on the screen content, the amount of determination movement may be increased or decreased depending on whether the count data is large or small, and the detection reference may be changed gently or strictly depending on the size of the count data.

〔Example〕

Next, this invention will be described in detail with reference to FIG. 1 showing an embodiment thereof.

In FIG. 1, the same symbols as those in FIG. 2 indicate the same things, and (8) is a judgment criterion variable type motion judging unit provided in place of the judging unit (5) in FIG. It is composed of a memory that stores each reference data of the determination characteristic, a digital comparator that compares each determination data with the input difference data, and outputs a motion information signal Dc.

Reference numeral (9) is a counting unit connected to the circuit unit (6), which is composed of a counter or the like and has a predetermined level through the circuit unit (6) at a preset N field cycle (N is an integer of 1, ...). The above signal Dc is repeatedly counted and count data is output.

(10) is a judgment control unit connected to the counting unit (9), which forms a detection control unit, and based on the content of the count data, outputs the selection data of the judgment characteristic to the judgment unit (8) and outputs the count data. The amount of determination movement is changed according to the above, and the determination characteristic is changed.

Then, the level of the signal Dc output from the determination unit (8) changes in accordance with the amount of noise in the video signal or the screen content, and the counter unit (9) causes the signal Dc via the circuit unit (6) to change. Among them, only the signal Dc having a level equal to or higher than a preset level, that is, a signal Dc when it is regarded as a moving portion having a level equal to or higher than a predetermined level is repeatedly counted in N field cycles.

Therefore, the count data output from the counting section (9) is the signal Dc of the moving part having a predetermined level or higher in each N field period.
It becomes the data of the number of.

The control unit (10) has, for example, a memory that operates using the count data as a read address, and selectively reads the selection data of each determination characteristic stored in the memory according to the count data to determine the determination unit (8). ).

Furthermore, the determination unit (8) operates, for example, as the read address of the memory of each detection characteristic that stores the input selection data, and changes the determination reference data to the data of the detection characteristic designated by the selection data. .

Therefore, the determination characteristic of the determination unit (8) is changed according to the count data, the determination movement amount for detecting a moving part is changed according to the count data, and the signal Dc is automatically changed according to the count data. Then, the detection characteristic of the moving portion is automatically variably adjusted.

By the way, when the video signal contains a lot of noise, the difference data of each one field becomes large as a whole regardless of the screen content of the video signal, and the signal Dc of a predetermined level or more continues in a large state.

In addition to the noise included in the video signal, when the screen content has many moving parts, the signal Dc of a predetermined level or more is larger than that when the moving parts have few moving parts.

Then, in order to eliminate the influence of noise and detect the moving part, the level of each reference data is changed to large or small depending on the size of the noise to change the detection reference of the moving part strictly or gently,
As the noise increases, the level regarded as a moving part may be increased and the determination motion amount may be decreased.

Therefore, when the detection characteristic is varied according to the magnitude of noise, the control unit (10) varies the reference level to high or low according to the magnitude of the count data to reduce the determination motion amount, Inversely proportional control means for outputting the selectable data to be increased or decreased is provided.

In this case, the detection characteristic is automatically and strictly changed depending on the magnitude of noise, and the moving portion is detected with an appropriate characteristic according to the noise amount.

On the other hand, in order to detect with appropriate characteristics according to the screen contents, the level of each reference data can be changed to small or large by increasing or decreasing the moving part, and the detection reference of the moving part can be changed slowly or strictly. As the number of moving parts increases, the level regarded as a moving part may be lowered.

Therefore, when changing the detection characteristics according to the screen contents,
As the control unit (10), selection data that is the opposite of the case where the noise is varied depending on the magnitude of noise. That is, a proportional control means for outputting selection data for increasing / decreasing the determination movement amount according to the magnitude of the count data is provided.

In this case, the detection characteristic is automatically changed strictly and gently depending on the number of moving portions of the screen content, and the moving portion is detected with an appropriate characteristic according to the amount of moving portions.

In addition, in the case of FIG.
The detection characteristic is changed by changing the judgment reference data of (8), but instead of changing the judgment reference data of the detection unit (8), based on the selection data, for example, the coring characteristics of the circuit unit (4) May be provided with detection control means for varying the detection characteristics by varying the differential data input to the determination unit (5), and based on the selection data, the input or output side of the circuit unit (6). A detection control unit that changes the detection characteristic by changing the level and changing the data output from the determination unit (5) to the output terminal (7) may be provided.

When the difference data is variable, a coring characteristic variable type preprocessing circuit unit may be provided in place of the circuit unit (4) and the selection data of the control unit (10) may be supplied to the circuit unit.

When the data output from the determination unit (5) to the output terminal (7) is changed, an input or output level variable type post-processing circuit unit is provided instead of the circuit unit (6), and the circuit unit is provided. Controller (1
It is sufficient to supply the selection data of 0).

On the other hand, the counting period (= N field) of the counting unit (9) may be set arbitrarily, and the reference data and selection data of the determination unit (8) and the control unit (10) can be switched by an electronic analog switch or the like. You may do it in.

And, of course, it can be applied to motion detection of images of various interlaced video signals of television systems.

[Advantages of the Invention] Since the present invention is configured as described above, it has the following effects.

Detecting a moving part according to a video signal by providing a counting unit and detection control means, and changing the judgment reference data, the input data or the output data of the motion judging unit according to the count data, and changing the judgment movement amount. The characteristics can be automatically and variably adjusted.

By providing an inversely proportional control means as the detection control means, the detection characteristic is automatically and rigorously and variably adjusted according to the magnitude of the noise of the video signal, and the characteristic is adjusted according to the noise amount. It can be detected.

Further, by providing the proportional control means as the detection control means, the detection characteristics are automatically loosely and strictly variably adjusted according to the number of moving parts of the video signal, and the appropriate characteristics according to the screen contents are adjusted. Can be detected with.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of an image motion detection circuit of the present invention, and FIG. 2 is a block diagram of a conventional image motion detection circuit. (3) …… Frame difference calculation unit, (8) …… Motion judgment unit, (9)
…… Counter, (10) …… Judgment controller.

Claims (3)

[Scope of utility model registration request] 1. An image motion detection circuit for digitally detecting the motion of the video signal from the inter-frame difference of the interlaced scanning video signal and outputting a signal of motion information of the video signal, wherein the video signal is digital. A digital conversion unit for converting, a frame difference calculation unit for calculating a difference between frames of output data of the conversion unit in a pixel unit or a block unit, and outputting difference data, and motion detection data obtained by converting the difference data into an absolute value. And a motion detection determination reference data to determine a motion amount, and output a motion amount data as a signal of the motion information, and a motion information signal of a predetermined motion amount or more in a predetermined field. A counting unit that repeatedly counts in a cycle, the judgment reference data according to the count data of the counting unit,
An image motion detection circuit comprising: a detection control unit that varies input data of the determination unit or output data of the determination unit, and varies a determination motion amount according to the count data. 2. An image motion detection circuit according to claim 1, wherein the detection control means is provided with an inverse proportional control means for decreasing or increasing the determination motion amount according to the magnitude of the count data. 3. An image motion detection circuit according to claim 1, wherein the detection control means is provided with a proportional control means for increasing / decreasing the determination motion amount according to the magnitude of the count data.