JPS6246107B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video signal processing device for drawing a trajectory of a moving object on a television screen.

If a moving object can be displayed sequentially along its trajectory on a television screen, excellent screen effects can be obtained. Objects that move particularly fast,
For example, as shown in Figure 1, in a baseball broadcast program, pitcher pitcher pitches 1 as 1 ₁ , 1 ₂ , etc.
If you can draw the trajectory by projecting the images in the order of 1 _{to 6} , it will be even more interesting.

The present invention provides a video signal processing device for achieving the above object, and embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows an embodiment of the invention, in which an input terminal 2 is supplied with a video signal obtained from, for example, a television camera. In this state, the start button 3 is pressed at the moment the target object starts moving, for example, at the moment the pitcher throws a ball.
As a result, the control circuit 4 is operated, and the switching signal obtained from the control circuit 4 causes the switch circuit 5 to start opening and closing operations at a predetermined period.
The video signal is converted into a digital signal having a predetermined number of bits by an A/D converter 6, and this digital signal is sampled by a switch circuit 5. Along with this, the digital signal is transferred to memory-7.
are sequentially written in by a write signal from the control circuit 4. In the following explanation, writing and reading of each memory, refreshing, and opening/closing of each switch circuit are all performed based on the write signal, read signal, clear signal, and switching signal output from the control circuit 4 at predetermined timings. be exposed.

The switch circuit 5 performs an opening/closing operation in which it is opened for an integral multiple of one field period of the video signal and closed for one field period. This opening/closing operation is performed based on the vertical synchronization signal of the digital signal applied to the control circuit 4. For example, if the time the switch circuit 5 is open is 0.1 seconds (6 field period), the output from the switch circuit 5 is 0.1 seconds.
One field of digital signals is sampled every second. This sampled signal is written into the memory 8 and applied to one input terminal of the difference signal detection circuit 9. When the signal for one sampled field is written into the memory 8, it is read out 0.1 seconds later.
This read signal is applied to the other input terminal of the difference signal detection circuit 9 and refreshed, and at this time the next sampled signal is written. That is, this memory 8 is for delaying the sampled signal by 0.1 seconds. The difference signal detection circuit 9 compares the levels of the signal sampled in real time and the signal sampled 0.1 seconds ago from the memory 8, and extracts the difference signal. Since no signals are written in the memory 8 at the initial stage, the first sampled signal is taken out as is and applied to the switch circuit 10. In the example of FIG. 1, the first sampled signal is the signal containing the image of sphere ₁₁ , and this signal will be written into memory 8 and applied to switch circuit 10. The switch circuit 10 is configured such that the switches 10a and 10b are closed alternately, and initially the switch 10a is closed.
When the sphere 11 is closed, a signal containing the sphere ₁₁ is written into the memory 11. Next, when 0.1 seconds have elapsed, the sampled signal at this time is written to the memory 8 and the difference signal detection circuit 9
added to. Also, the previously sampled signal is read out from the memory 8 and the difference signal detection circuit 9
is added to the sampled signal, and the difference between the sampled signal and the sampled signal is taken. _{The sampled signal at this time is a signal containing spheres 1 and 2 in FIG .} If so, the difference between the two signals is taken, and thereby the sphere 1 ₁ and 1
A signal containing only _{the second} part is extracted as a difference signal. In this case, one of the spheres 1 ₁ and 1 ₂ , for example sphere 1 _1, is inverted with respect to sphere 1 ₂ , so it becomes a black level signal, and sphere 1 ₂ becomes a white level signal. The signals from the spheres 1 ₁ and 1 ₂ are written into the memory 12 through the switch 10b. In this state, the signal of the bulb 1 ₁ is written in the memory 11 at the normal level, that is, the white level, and the signal of the bulb 1 ₁ with the black level and the signal with the bulb 1 ₂ with the white level is written in the memory 12. .

When the next sampling is performed in this state, the signal including spheres 1 _{to 3} is sampled and the memory 8
and is added to the difference signal detection circuit 9. The difference signal detection circuit 9 compares the signal containing the spheres ₁₃ with the signal containing the spheres ₁₂ read out from the memory 8. At this time, if the balls 1 _{and 3} have moved sufficiently relative to the balls 1 and ₂ , a difference signal between the black level for the balls 1 _{and 2} and the white level for the balls 1 _{and 3} will be obtained for the same reason as mentioned above, and this difference signal is transferred to the memory 11 through the switch 10a.
will be written to. Along with this, memory 11, 12
The reading of the signal previously written to is started,
The read signal is sent to contact a of the switch circuit 13,
b and digital filter 1.
Added to 4. This digital filter 14 can obtain an output signal only when the signals applied to its two input terminals are at black level and white level, and is constituted by an exclusive OR circuit. The switch circuit 13 is configured so that contacts a and b are alternately switched each time the output signal is applied from the digital filter 14. Therefore, from the memory 11 to this digital filter 14, the sphere 1 ₁
At the same time as the white level signal of
When the black level signal of the bulb ₁₁ is applied from the digital filter 14, an output signal is obtained from the digital filter 14, and this output signal causes the switch circuit 1
3 is closed to contact a. Therefore, at this time, a signal from the bulb ₁₁ at the white level is obtained from the switch circuit 13. At the same time, the memory 11 is refreshed and the difference signal, that is, the black level sphere ₁₂ and the white level sphere ₁₃ are written. Also memory 1
2, a black level ball ₁₁ and a white level ball ₁₂ are written.

When the next sampling is performed, the difference signal detection circuit 9 outputs the black level spheres 1 _{to 3} and the white level spheres 1 _{to 4.}
A difference signal is obtained, and this difference signal is sent to switch 10b.
The information is written into the memory 12 through the memory 12 and read from the memories 11 and 12. As a result, the signal of the black level sphere 1 _{and 2} of memory 11 and memory 1
When the signal of the bulb 1 ₂ at the white level of 2 is read out, the switch circuit 13 is closed to contact b by the output signal of the digital filter 14, and the signal of the bulb 1 ₂ of the white level is read out from the switch circuit 13. is obtained. At the same time, the memory 12 is refreshed. By repeating the above operation, the switch circuit 13 outputs the white level balls 1 ₁ , 1
₂ to ₁₆ signals are obtained sequentially. If this signal is taken out from the output terminal 15 and converted into D/A, only the sphere will be displayed as 1 ₁ , 1 ₂ to 1 on the television screen.
It can be projected every 0.1 seconds in the order of ₆ .

Further, the signal taken out from the switch circuit 13 is applied to the B terminal and S terminal of the line selector 16. This line selector 16 switches internal contacts when input signals are applied to the A and B terminals and a signal is applied to the S terminal, and the signal applied to the B terminal is obtained from the Y terminal. When no signal is applied to the terminal, the signal applied to the A terminal from the memory 17 is obtained from the Y terminal. That is, when there is a sufficient movement distance between the spheres of the two input signals applied to the difference signal detection circuit 9, a difference signal is obtained, and this difference signal is written in the memory 11 or 12 and then read out. In this case, this difference signal is passed preferentially, and when the movement distance is small and there is no difference signal, the signal from the memory 17 is passed and this signal is written again. Now, assuming that a difference signal is obtained for every sampling, the spheres 1 ₁ , 1 ₂ to 1 obtained sequentially from the switch circuit 13
The signals No. ₆ are written into the memory 17 in this order. If there is no difference signal during this period, the memory 17 is read out during this period, and this read signal is written again through the line selector 16. By preferentially writing the difference signal in this way, the spheres 1 ₁ , 1 ₂ to 1
For example, if the _{balls 6} are partially overlapping, for example, the ball 1 ₁
If and 1 and ₂ partially overlap, ball 1
₁ is written except for the overlapping part, and sphere ₁₂ is written entirely. By this, for example, the ball 1 ₁ ,
When the brightness of 1 ₂ to _{1 6} is changing, the outline of the subsequent sphere can always be clearly defined. When writing to the memory 17 is completed through the above operations, reading from the memory 17 is started.
At the same time, the signals written up to that point are read from the memory 7, and these read signals are converted into analog signals by the D/A converters 18 and 19, respectively, and synthesized by the mixer circuit 24. The resulting signal is obtained at the output terminal 21. D/A
Since the signal from the converter 18 is the video signal of the spheres 1 ₁ , 1 ₂ to _{1 6} and the signal from the D/A converter 19 is the original video signal, based on the combined signal of the two, Balls 1 ₁ , 1 ₂ on the television screen
1 ₆ can be projected sequentially on its trajectory along with the background image while leaving the image of the previous ball.

In this embodiment, if there is an object other than a ball that moves at a high speed among the objects to be photographed by the camera, a difference signal for that object will be obtained. As a result, in addition to the trajectory of the ball, the trajectory of other objects is also displayed on the television screen, and the trajectory of the target ball may not be clear. As a countermeasure to this problem, for example, if a digital filter is provided downstream of the difference signal detection circuit 9 to pass only a signal having a level and frequency corresponding to the ball signal, the above problem can be considerably improved. Furthermore, in the embodiment, a case was described in which a television camera was used as a signal source, but as a signal source,
It may be a VTR, and in the case of a VTR, a reproduced slow video signal may be applied to the input terminal.

The present invention comprises a means 5 for sampling a digital video signal in a predetermined period every predetermined period, a means 8 for delaying the sampled signal by at least one period, and a means for sampling the sampled signal and the delayed signal. means 9 for obtaining a signal of the difference between
first and second storage means 11 and 12 in which the difference signals are written alternately, and an exclusive OR circuit 14 to which the signals read from the first and second storage means are supplied; A switch circuit 13 is provided which alternately selects the signals read out from the first and second storage means each time a predetermined output signal is given from the exclusive OR circuit, The present invention relates to a video signal processing circuit configured to sequentially obtain signals exceeding .

Therefore, according to the present invention, a moving object can be sequentially displayed on the television screen along its trajectory.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a television screen obtained by the present invention, and FIG. 2 is a circuit diagram showing an embodiment of the present invention. 1 ₁ , 1 ₂ to 1 ₆ ... ball, 5 ... switch circuit, 6 ... A/D converter, 8 ... memory, 9 ...
...Difference signal detection circuit, 11, 12...Memory, 1
3...Switch circuit, 15...Output terminal.

Claims (1)

[Scope of Claims] 1. Means for sampling a digital video signal in a predetermined period at each predetermined cycle; means for delaying the sampled signal by at least one cycle; and means for delaying the sampled signal by at least one cycle; means for obtaining a difference signal from the signal;
storage means; an exclusive OR circuit to which the signals read from the first and second storage means are supplied; and each time a predetermined output signal is given from the exclusive OR circuit, the and a switch circuit that alternately selects the signals read out from the second storage means, and sequentially obtains signals exceeding a predetermined level from the switch circuit.