JPH03139987A - Movement detecting circuit - Google Patents

Abstract

PURPOSE:To prevent a movement detecting signal generated at the periphery of a vertical edge from being erased by outputting either one of a binary movement detecting signal newly set up based upon the movement detecting signals of plural picture elements and a movement detecting signal to be the output of a correlation detecting means. CONSTITUTION:When a vertical edge is large, a selector 37 selects a signal outputted from a movement detecting circuit 33 in accordance with binary signals '0', '1' outputted from a vertical edge detecting circuit 36, and when the vertical edge is small, selects a signal from a setting circuit 35 and outputs the selected signal from an output terminal 32. Since the signal from the movement detecting circuit 33 is directly outputted in the vertical edge part in which an original movement detecting signal may be erased by a counting circuit 34 and a setting circuit 35, the original movement detecting signal can be prevented from being erased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a motion detection circuit that detects the motion of a subject in a video signal.

Conventional technology In recent years, as television receivers have become larger and have higher image quality, technologies such as motion-adaptive three-dimensional Y/C separation and sequential scanning, which make full use of digital signal technology using memory elements, have been introduced. has been done. The key to these motion-adaptive three-dimensional Y/C separation and progressive scanning techniques is a motion detection circuit that detects the motion of a subject in a video signal.

FIG. 6 is a block diagram of a motion detection circuit proposed in Japanese Patent Application No. 63-150749. In Figure 6,
1 is an input terminal, 2 is an output terminal, 3 is a motion detection circuit, 4 is a counting circuit, and 5 is a setting circuit.

First, a video signal input to the input terminal 1 is applied to the motion detection circuit 3.

The motion detection circuit 3 is composed of a circuit shown in FIG. 7, for example.

In FIG. 7, 11 is a frame delay device, 12 is a subtracter, 13 is a low-pass filter, 14 is an absolute value circuit, and 15
is a comparator. The video signal input to input terminal 1 is
For example, it is delayed by one frame period by a one frame delayer 11 realized by a frame memory (525H memory),
An interframe difference signal is obtained in the subtracter 12. By inputting this to the low-pass filter 13, motion information of the low frequency component is obtained, and after taking its absolute value in the absolute value circuit 14, it is input to the non-inverting input of the comparator 15. If the absolute value of this motion information exceeds a certain threshold, it is determined to be a moving image, and a logical value of 1 is output, for example.If it does not exceed the threshold, it is determined to be a still image, and a logical value of 0 is output, for example. do.

These data may also include data that is erroneously determined to be a moving image even though it is a still image due to the influence of noise and has a logical value of "1".

Next, the output of the motion detection circuit 3 is input to the counting circuit 4,
The number of occurrences of the logical value "1" is counted.

The counting circuit 4 is composed of a circuit shown in FIG. 8, for example.

In Fig. 8, 2] is an input terminal, 22 is an output terminal, 2
3 is an adder, 24a and b are 1-line delay devices, 25a to 2
5f is a 1-pixel delay device. The data at each point M1 to M9, which is input to the adder 23 in FIG. 8, corresponds to the data indicating the still image or moving image mode at each pixel M] to M9 in FIG. There is. In other words, with the configuration shown in FIG. 8, the number of occurrences of the logical value "1" in an area of 3 pixels in the horizontal direction and 3 lines in the vertical direction, totaling 9 pixels, is counted by the adder 23, and the counting result is sent to the output terminal. 22
It is output from

Next, the setting circuit 5 is composed of a comparator as shown in FIG. 10, for example. The comparator shown in Figure 10 compares the number of occurrences of the logical value "1" in the 9-pixel area with the darkness value, and if it exceeds the threshold, the logical value is determined as a value caused by the movement of the subject. “1” is output. If the threshold is not exceeded, the logic value is “O” as false data generated due to noise.
Output. For example, if the threshold value of the setting circuit is "4", and if only one pixel in the 9-pixel area becomes a logic value "1" due to the influence of noise, the output of the counting circuit 4 in FIG. 6 will be "1". ”, which is smaller than the threshold value “4” of the setting circuit 5, so data from the pixel whose logical value is “1” is ignored. In this way, the motion detection circuit shown in FIG. 6 can remove false motion signals caused by noise or the like.

Problems to be Solved by the Invention In the motion detection circuit configured as described above, for example, when a figure as shown in FIG. The logic value "1" is generated in the 9-pixel area as shown in FIG. Therefore, the output of the counting circuit 4 is "3", and the threshold value "
4'', its output will be a logic value of ``0''.

In other words, all of this motion data will be erased.

As described above, the configuration of the conventional example described above has a problem in that not only the false motion data caused by noise etc. but also the original motion data are removed.

In view of the above problems, the present invention correctly outputs a motion detection signal generated at a vertical edge as described above without erasing it, and
Another object of the present invention is to provide a motion detection circuit that removes false motion detection signals caused by noise or the like.

Means for Solving the Problems In order to solve the above problems, the motion detection circuit of the present invention includes means for detecting temporal correlation of a subject in an input video signal, and a method for detecting a signal from the means for detecting the correlation. means for counting the number of occurrences within an arbitrary area around the pixel of interest; means for setting a new signal based on the counting result of the counting means;
means for detecting the size of the edge in the vertical direction of the subject in the human video signal; and means for switching the signal from the signal setting means.

According to the above configuration, the present invention generates a newly set binary signal based on the motion detection signal of multiple pixels, which is the output of the setting means, as a motion detection signal generated around the vertical edge of the subject of the input video signal. By outputting either the motion detection signal or the motion detection signal that is the output of the correlation detection means, it is possible to prevent the motion detection signal generated around the vertical edge from being removed, and to prevent the motion detection signal generated around the vertical edge from being removed. false motion detection signals can be removed.

Embodiment Hereinafter, a motion detection circuit of the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram of a motion detection circuit according to a first embodiment of the present invention. In FIG. 1, 31 is an input terminal, 32 is an output terminal, 33 is a motion detection circuit, 34 is a counting circuit, 35 is a setting circuit, 36 is a vertical edge detection circuit, and 37 is a selector.

First, a video signal input to the input terminal 31 is guided to a motion detection circuit 33. The motion detection circuit 33 detects the temporal correlation of the subject, and if it is determined that the subject is moving (a moving image), it outputs a logic value of "1", for example, and the subject is stationary (still IF:, an image). If it is determined that this is the case, a logical value of "0" is output. Next, in the counting circuit 34, a setting circuit 35 calculates the number of occurrences of logical value "1" in a certain area based on the counting result.
The value of the pixel of interest is set in . The operation up to this point is the same as that described in the conventional example.

The video signal input to the input terminal 31 is a motion (time correlation)
At the same time as being supplied to the detection circuit 33, it is also supplied to the vertical edge detection circuit 36.

The vertical edge detection circuit 36 is realized, for example, by a circuit as shown in FIG. In FIG. 2, 41 is an input terminal, 49 is an output terminal, 42 is a Ronox filter, and 43a
, b is a one-line delay device 44a.

b is a subtracter, 45a and b are absolute value circuits, 46 is a maximum value selection circuit, and 47 is a comparator.

The operation will be explained below with reference to FIG. Third
The waveforms (a) to (hl) in the figure correspond to the video signal waveforms at points a-h in FIG. 2, respectively.

First, a video signal inputted from an input terminal 41 is passed through a low-pass filter 42 to remove its noise components. Assuming that the input video signal is, for example, a rectangular wave, the waveforms shown in Figure 3 (al, (bl) (C1) are obtained at points a, b, and c in Figure 2. All waveforms are shown when viewed in the vertical direction of the screen. The signal (a) from which noise has been removed after passing through the low-pass filter 42 is delayed by IH (signal fbl) by the 1-line delayer 43a, and further delayed by LH by the 1-line delayer 43b, for a total of 2H. These signals ta+(b) and fcl undergo subtraction processing in the subtracters 44a and b, respectively.The outputs of the subtractors 44a and b are as follows.
The waveforms fdl and tel in Fig. 3 are obtained, respectively. The outputs fdl and tel are converted into absolute values by the absolute value circuits 45a and 45b to obtain the output waveform of (gl) as shown in FIG. The larger value is selected and output.Therefore, when the signals shown by +f+ and Igl in FIG. 3 are input to the maximum value selection circuit 46, the waveform fhl in FIG. 3 is obtained as the output. This waveform shows the presence or absence of edges in the vertical direction of the input rectangular wave.Specifically, the former rectangular wave component of waveform fh) covers the edge portion from the black level to the white level, and the latter rectangular wave component It shows the edge part from the white level to the black level.

Next, the comparator 47 compares the output (hl) of the maximum value selection circuit 46 with the threshold value, and if it is larger than the threshold value, it outputs a logic value of "1", and if it is smaller, it outputs a logic value of " In other words, the size of the edge in the vertical direction is detected, and when it is determined that the edge is large, the logical value C is “1”.
”, and if it is determined that it is small, a logical value of “0” is output from the output terminal 49. This output signal is used as the selection signal of the selector 37 in FIG. 1.The input signal of the selector 37 The signals include the signal from the setting circuit 35 and the output signal of the motion detection circuit 10 that does not pass through the counting circuit 34 and the setting circuit 35. According to "1", when the vertical edge is large (detection circuit 36 output = "1"), the signal from the motion detection circuit 33 is selected, and when the vertical edge is small (detection circuit 36 output = "0"), the signal from the motion detection circuit 33 is selected. The signal from the setting circuit 35 is selected and output from the output terminal 32.In other words, the signal from the motion detection circuit 33 is selected at the vertical edge portion where the original motion detection signal may be erased by the counting circuit 34. By outputting the signal as is, the original motion detection signal is prevented from being erased.

FIG. 4 is a block diagram of a motion detection circuit in a second embodiment of the present invention. In the figure, 31 is an input terminal;
2 is an output terminal, 33 is a motion (time correlation) detection circuit, 34
1 is a counting circuit, 35 is a setting circuit, and 40 is a selector, which is the same as the configuration shown in FIG. The differences from the configuration in Figure 1 are as follows. The output from the setting circuit 35 is supplied to one input of the selector 40, while the logical value "1" indicating that the subject is moving is input as a fixed value to the other input. It is. Second, the output of the motion detection circuit 33 is connected to the horizontal correlation detection circuit 4 and is used as a selection control signal for the selector 40.
The point is that the output signal of is used.

The operation of the motion detection circuit configured as in ``-2'' will be explained below.

The video signal applied to the input terminal 31 in FIG. 4 is input to the motion detection circuit 33. The output of the motion detection circuit 33 is reset to a new value by a counting circuit 34 and a setting circuit 35, and then supplied to one input of a selector 40. The operation during this time is similar to that described in the conventional example, and for example, a logical value "1" is output when the image is determined to be a moving image, and a logical value "0" is output when the image is determined to be a still image.

The output of the motion detection circuit 33 is simultaneously transmitted to the horizontal correlation detection circuit 41.
is also supplied. The horizontal correlation detection circuit 41 is realized, for example, by a circuit as shown in FIG. In FIG. 5, 61 is an input terminal, 69 is an output terminal, 62a and b are 1-pixel delay units, 63 is an adder, and 64 is a comparator.

In FIG. 5, the signal at the input terminal 61 has a logical value of "1", for example, when the subject moves. Therefore, the number of pixels determined to be a moving image in a three-pixel area in the horizontal direction is output to the adder 63. This number and threshold C
are compared by a comparator 64, and if it is larger than the threshold C, it is determined that there is a correlation in the horizontal direction and outputs a logic value of "1", for example.

If it is small, it is assumed that there is no correlation in the horizontal direction and a logical value of "0" is output. This signal is output from the output terminal 69 and is used as a selection control signal for the selector 40 in FIG. The other input of the selector 40 is a logical value "l" indicating a moving image.
” is fixed.

Generally, a motion signal generated when a subject with vertical edges moves in the vertical direction has a strong correlation in the horizontal direction, so this horizontal correlation detection circuit 41 detects it and outputs the motion detection signal as a logical value "1". do. By doing so, the counting circuit 34. The setting circuit 35 does not erase the original movement. Furthermore, for motion signals for which horizontal correlation is not detected by the horizontal correlation detection circuit, it has the effect of removing false motion signals caused by noise, etc., as in the past.

Note that the counting circuit of the first embodiment has three lines in the vertical direction;
Although the case of an area of 3 pixels in the horizontal direction is shown, the area is not limited to this size and may be larger.

Further, in the horizontal correlation detection circuit of the second embodiment, a detection method is shown in an area of three pixels in the horizontal direction, but the present invention is not limited to this, and an area of three or more pixels may be used.

Effects of the Invention According to the present invention, there is a means for detecting the temporal correlation of a subject in an input video signal, and the number of signals generated from the means for detecting the correlation is counted in an arbitrary area around a pixel of interest. means for setting a new signal based on the counting result of the counting means; means for detecting the size of an edge in the vertical direction of the subject of the input video signal; and detecting the size of the edge. By providing a means for switching between a signal from the means for detecting the correlation and a signal from the means for setting the signal based on the detection signal from the means for detecting the correlation, the motion detection signal generated around the vertical edge of the subject of the video signal can be detected. It is possible to prevent false motion detection signals from being mistakenly removed, and it is also possible to remove false motion detection signals caused by noise or the like.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a motion detection circuit in the first embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the vertical edge detection circuit in FIG. 1, and FIG. 3 is a block diagram showing the operation of the vertical edge detection circuit. 4 is a block diagram showing the configuration of a motion detection circuit in the second embodiment of the present invention; FIG. 5 is a block diagram showing the configuration of the horizontal correlation detection circuit in FIG. 4; 6 is a block diagram of a conventional motion detection circuit, and FIG. 7 is a block diagram showing the main part configuration of the motion detection circuit shown in FIG. 6.
8 is a block diagram showing the configuration of the counting circuit in FIG. 6, FIG. 9 is a plan view showing pixels to explain the operation of the counting circuit, and FIG. 10 is the configuration of the setting circuit in FIG. 6. 11 and 12 are a waveform diagram and a plan view for explaining the problems of the conventional example. ]... Input terminal, 100... Output terminal, 10... Time correlation detection circuit, 20...
Counting circuit, 30...Setting circuit, 40...
・Vertical edge detection circuit, 50...Selector, 60
...Horizontal correlation detection circuit.

Claims (2)

[Claims] (1) means for detecting the temporal correlation of a subject in an input video signal; and means for counting the number of motion detection signals generated from the means for detecting the correlation within an arbitrary area around the pixel of interest; means for newly setting a motion detection signal based on the counting result of the counting means; means for detecting the presence or absence of an edge in the vertical direction of the subject in the input video signal; and means for detecting the presence or absence of an edge in the input video signal. A motion characterized by comprising means for selectively outputting a signal from the means for detecting the correlation based on the detection signal and a signal from the means for newly setting the signal as a motion detection signal. detection circuit. (2) means for detecting the temporal correlation of the subject of the input video signal; and means for counting the number of motion detection signals generated from the means for detecting the correlation within an arbitrary area around the pixel of interest; means for newly setting a motion detection signal based on the counting result of the counting means; means for detecting horizontal correlation of the motion detection signals from the correlation detecting means; and means for selectively outputting a signal from the setting means and a signal having a fixed value based on the detection result from the motion detection means and selectively outputting the signal as a motion detection signal. Motion detection circuit.