JPS6248432B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television image processing device, and more particularly to a moving object trajectory display device that displays the trajectory of a desired moving object, such as a baseball ball.

Conventionally, an image of a moving object is detected by comparing a video signal for one frame at a certain point with a video signal for one frame m (m is an integer) frames before, and the detected image of the moving object is There is known a device that displays the trajectory of a moving object by sequentially storing frames in an image memory in a superimposed manner (Japanese Patent Publication No. 51-12369).

However, in this case, if you compare the entire screen, all moving objects on the screen will be detected.For example, even if you try to display the trajectory of a baseball ball, the movements of the pitcher, catcher, etc. will also be detected. This has the disadvantage that the screen becomes unsightly. Therefore,
It is conceivable to generate a window signal that defines a desired area (window) on the television screen and perform comparison only within this window to detect only the desired moving object image. Since the image moves frame by frame, the window must also move accordingly.For example, in a baseball game, the operator may want to display the trajectory of a ball thrown by a pitcher while watching the television image. When doing so, it is necessary to input the position of the window each time using a light pen or the like so as to follow the ball, which is extremely troublesome.

The present invention provides a moving object trajectory display device for television images that can clearly display only the desired trajectory of a moving object by automatically moving the position of a window as the moving object moves. The purpose is to

An embodiment of the present invention will be described below. 1st
In the figure, a video signal is sent from a continuous television video signal source 10, such as a television camera, through an OR gate 22 to a video memory 20 for one television screen, such as a frame synchronizer.
In this way, one frame worth of video signal at a certain point in time is stored. Note that the OR gate 22 is
Like the AND gate 21, it actually also has a video signal processing function, but for convenience, it will be explained in terms of a logic gate. The stored video signal is sent to a subtraction (comparison) circuit 30 (which actually also has a video signal processing function) and is compared with the video signal m frames later. When the current video signal is subtracted from the video signal m frames before, the positive pulse resulting from the subtraction becomes a signal indicating the position of the moving object m frames before, and the negative pulse from the subtraction result becomes a signal indicating the position of the moving object m frames before. The pulse becomes a signal indicating the current moving position. The obtained current moving object position signal is input to the AND gate 31 together with the window signal from the window signal generation circuit 40. As a result, subtraction is performed only within the window, and if there are no other moving objects within the window, the position of the desired moving object can be reliably detected. this
The output of the AND gate 31 is sent to the window signal generation circuit 40 via the OR gate 33. In addition, a signal from a light pen or the like indicating the initial position of the desired moving object is input to the OR gate 33.

The window signal generation circuit 40 generates a window signal that defines, for example, a window (area) having a desired width in the vertical and horizontal directions of the television screen centered on the input position signal, for example, in accordance with the input position signal.
Therefore, for example, the ring counter 41 counts the horizontal synchronizing signal and makes one cycle in the vertical scanning period, and the ring counter 41 counts the clock signal which is phase-locked to the horizontal synchronizing signal and has k times the frequency of the horizontal synchronizing signal and makes one cycle in the horizontal scanning period. A ring counter 42 is provided, and both counters 41 and 42 are reset by the position signal. Each counter 41, 42
After being reset by a position signal, until the next position signal is input, the ring count is performed with the time point at which the position signal is input as "0" (reset state). "i" and "j" before and after "0" of the counter 41 and "p" and "q" before and after "0" of the counter 42 are decoded, and flip-flops 43 and 44 are set with these decoded outputs.
If the outputs of both flip-flops 43 and 44 are input to the AND gate 45, the AND gate output will be
j, the window signal has a width of p to q in the horizontal direction, and the current position signal is located at the center thereof.

This window signal is input to the window memory 50 via the OR gate 51. This window memory 50 consists of a one-bit ("0", "1") area memory on the amplitude side. The output of this window memory 50 is
The signal is inputted again to the window memory 50 through the OR gate 51, and the window signal is stored in a superimposed manner. The output of window memory 50 is sent to AND gate 32. The position signal of the moving object m frames before is input to this AND gate 32, and as a result, the window (window memory 5
(defined by an output of 0), this means that the position of the moving body was detected m frames before. this
The output of the AND gate 32 is sent to the AND gate 21 to which the output of the video memory 20 is sent. Therefore, only the image of the moving object is extracted from the video signal m frames before and sent to the video memory 20 via the OR gate 22. That is, m frames after the first storage, only the image of the moving object among the first stored video signals is superimposed on the current video signal and stored in the video memory 20.
will be memorized.

After the next m frames (2m frames from the beginning)
, a video signal on which the moving object image of the first frame is superimposed is sent to the subtraction circuit 30. thus
The position signal of the moving body after 2 m frames is sent to the AND gate 31, and the position signals of the moving body after the first frame and m frames are sent to the AND gate 32. The window signal input to the AND gate 31 has predetermined sizes i~j, p~ so that the moving object will enter the window after m frames have elapsed.
It has q. Therefore, by inputting this new position signal, a window signal whose position has moved by the same magnitude (moved so that the new position signal is located at the center of the window) is obtained.

To explain this situation with reference to Figure 3A, the moving object is at position A in the first frame, at position A' after m frames, at position A'' after 2m frames, and at position A after 3m frames. , and after 4 m frames, it moves to A〓.In the first frame, position A is input using a light pen, etc., and a window signal (shown by a dotted line) is created so that position A is the center.A' As long as the position of is within this window, the wind signal moves with the same magnitude so that A' becomes the center. After 2 m frames, the wind signal continues to move in the same way so that the center is at the new moving object position. moves.

As a result, the moved windows are stored in the window memory 50 in a superimposed manner one after another, as shown in FIG. 3C. Note that if the range of movement of the moving body is predicted in advance, the window memory 5
0 storage operation is not performed as described above, the light pen is moved along the predicted trajectory, and the window signal generation circuit 40 is operated in the same manner as described above.
You may also perform the task of storing the window group in the window memory 50. Furthermore, the method of creating a group of windows in advance is not limited to using a light pen. The output of this window memory 50 is sent to the AND gate 32. Therefore, for example, after 2m frames, only the moving objects after the first frame and m frames are detected, and after 4m frames, the first frame, after m frames, after 2m frames, etc.
Since only the four moving objects after 3 m frames are detected, their respective positions can be detected reliably. Therefore, the output of the AND gate 21, which is controlled by the output of the AND gate 32, also indicates the image of the moving object at position A after m frames, so the output of the OR gate 22 is as shown in FIG. As shown in b, the moving object image in the first frame is superimposed on the entire image after m frames (including the moving object image after m frames), and after 4 m frames, A→A′→ The moving objects that have moved from A'' to A to A are all superimposed on the image 4m frames later, as shown in Figure 3B.The video signal on which such past moving object images are superimposed is When the signal is taken out as an output signal from the OR gate 22 or the video memory 20 and displayed on a television picture tube, it is displayed as the locus of the moving object as shown in FIG. 3B.

Note that the output of the AND gate 32 is connected to the video memory 2.
0 as a rewriting prohibition signal, and the previous memory is retained without being rewritten while this signal is input, only images of past moving objects will be saved without being rewritten. The same is true.

As described above, the present invention includes a window signal generation circuit that generates a window signal that defines a window having a predetermined area in the vertical and horizontal directions within one screen of a television image; A comparison circuit that detects an image of a moving object within the window by comparing a video signal for one screen at a time with a video signal for one screen at a predetermined time before, and sequentially superimposes the detected images of the moving object. In a moving body trajectory display device for television images, which is comprised of an image memory that stores images such as
A circuit that resets a ring counter that is incremented by 1 in the vertical scanning period and a ring counter that is incremented by 1 in the horizontal scanning period using the moving object image signal output from the above-mentioned comparison circuit, etc. Since it is equipped with a circuit that changes the directional timing and the horizontal direction timing, it is possible to detect only the locus of the moving object within the window and automatically follow the movement of the moving object, thereby making it possible to detect the movement of the desired moving object. Only the trajectory can be clearly displayed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
FIG. 2 is a waveform diagram for explaining the operation of FIG. 1,
Figures 3A, 3B, and 3C are diagrams showing signals displayed on the television screen, Figure 3B shows the relationship between the window and the position of a moving object, and Figure 3B shows past images of a moving object. The superimposed video signal is shown, and FIG. 3C shows the output signal of the window memory. 10...Television video signal generation source, 20...
...Video memory, 30...Subtraction circuit, 40...Window signal generation circuit, 41, 42...Counter, 5
0...Wind memory.

Claims (1)

[Claims] 1 A window signal generation circuit that generates a window signal that defines a window having a predetermined area in the vertical and horizontal directions within one screen of a television image, and a video signal for one screen at a certain point in time and a window signal at a predetermined time ago. Movement in a television image consisting of a comparison circuit that detects an image of a moving object within the window by comparing video signals for a screen, and an image memory that stores images of the detected moving object so as to be sequentially superimposed. In the body trajectory display device, the window signal generation circuit includes a circuit that changes the vertical timing and horizontal timing of the window signal in accordance with the moving body image signal output from the comparison circuit. A device for displaying moving object trajectories in images.