JPS6131819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for immediately and highly accurately measuring the moving speed of a moving object in a subject imaged in, for example, television broadcasting, using the playback screen. The measurement results are
For example, this was done in anticipation of new program effects, such as prompt display on the screen of the program being broadcast.

Conventionally, to measure the speed of a moving object in a subject imaged using a television system, the number of fields from the desired measurement start point to the end point of the moving object was counted, but the current standard television system in Japan In this method, the number of images per second for a moving image is 60 seconds, so the time measurement resolution is 0.0167 seconds, which is sufficient for measuring moving objects that are faster than that, such as a pitched ball in a baseball program. I couldn't do it.

On the other hand, the present invention relates to a method of measuring the horizontal scanning period with an accuracy equal to or higher than the horizontal scanning period of current televisions.

The method of the present invention will be described in detail below based on Examples.
FIG. 1 is a schematic diagram of the configuration of a conventional color television camera, in which light passing through a lens L is guided to an R, G, and B image pickup tube through a three-color separation system. In order to obtain a television screen according to the present invention, for example, as shown in FIG. 2, an imaging system M is added to the imaging system shown in FIG. A part of the emitted light is separated into three-color separation system 1, and the output of this newly added additional image pickup tube M is used. Note that in this example, the green component is separated, but there is no problem in separating light components in a shorter wavelength range than the green component, and the key is to minimize the loss of light to the image pickup tube G for the green component. It is desirable to perform spectroscopy from such light components. Each of the R, G, and B image pickup tubes operates at a vertical scanning frequency _fv according to the so-called standard television system, whereas in this embodiment, the additional image pickup tube M
operates at a higher vertical scanning frequency (field frequency) nf _v . However, the horizontal scanning frequency is the same standard television system frequency as the R, G, and B image pickup tubes. As a result, line interlacing in this case is scanned at a ratio of 2n:1. Therefore, the transmission speed (signal band) of the output signal of the additional image pickup tube M can be the same as that of the standard television signal.

The output signal of this additional image pickup tube M is applied to a processing amplifier 3 via a head amplifier 2 as shown in FIG. . In this embodiment, the output of the additional image pickup tube M is designed to facilitate the operation of specifying the capture start and end points of a moving object image on a television playback screen of a fast-moving object using, for example, a light pen. The signal is sequentially written in field images using a plurality of disks in the same manner as disks are used for well-known slow-motion television.

That is, in FIG. 3, reference numeral 4 denotes a memory device for this purpose, for example, a magnetic disk capable of recording images of a plurality of fields is used, and the next field image is sequentially written in field units for each field. Figure 4 shows the imaging output signal when n is 4 at the vertical scanning frequency _nfv of the additional image pickup tube M, the writing of the signal to the disk, and each written field image four times at the standard television field rate. This figure shows the flow of signals that are repeatedly reproduced to obtain slow motion images.

That is, a is the waveform of the field rate of the standard television signal, and b is the output signal waveform of the additional image pickup tube M when n=4. 1-3 and 1-
Obtain output signals of 4 field images as shown in step 4.
cf shows field images written to each of the four magnetic disks constituting the memory device 4 and their relative relationships, and are written to each disk one after another in field units as shown.
These are sequentially reproduced four times in succession in the vertical scanning period of standard television to obtain a so-called slow motion television signal as shown in g.

In this case, each of the above disks has fv=60, n=
4, so the rotation speed is 60×4×60=14400r.
You can change it to pm.

FIG. 5 shows the slow-motion signal shown in FIG. This shows the writing state of the disk from which the video signal is obtained. In the figure, a indicates the field rate of the standard television signal, and b indicates the field rate of the additional image pickup tube M when n=4. c to f are the recording states of each disk No. 1 to No. 4, and image signals for four consecutive fields are recorded during one period of the disk.
Each disk No. 2, No. 3, and No. 4 receives the output signal of the additional image pickup tube M by 1 field + 1/8.
H, 2 fields + 1/4H, 3 fields + 3/8H
Record each delayed signal.

Similarly, for disks No. 5 to No. 8, 2-1, 2-2, 2-3, 2-4 following the 1-1, 1-2, 1-3, 1-4 fields. Field images are recorded as shown in gj.

By switching the head outputs of the disks No. 1 to No. 4 recorded in this way and repeatedly reproducing them four times each, the slow motion video signal shown in FIG. 4g can be obtained.

The video signal thus reproduced is reproduced and displayed on the monitor shown at 5 in FIG. In this reproduced display image, the vertical resolution of a single field image is reduced to 1/n compared to the image when a standard television signal is reproduced, but for a moving image, the vertical resolution is reduced by n times. Images are being played that can be expressed at slow motion speeds. This corresponds to a television system in which the time-frequency band is n times wider than that of a standard television signal.

On the television screen played in this way,
As shown in FIG. 3, by manually capturing and instructing the desired measurement start and end points of the moving body image to be measured using a pointing device such as a light pen 6, which is mainly composed of a photoelectric conversion element, Photoelectric conversion pulse signals with timings corresponding to the positions of both points on the television screen are obtained.

The pulse signals at both points thus obtained are led to the counting circuit 7, and the pulse corresponding to the measurement start point is used as the start pulse to start counting the horizontal scanning period, and the pulse signal corresponding to the end point is used as the end pulse. If you count the number of horizontal scanning periods until the end pulse of the lever, since the horizontal scanning period is fixed, you can immediately measure the travel time of the moving object from the measurement start point to the end point from the counted value. can.

Therefore, it is very easy to calculate the speed of a pitcher moving between pitches and catches on a television screen where the distance traveled by the moving object is determined, such as between pitchers and catchers in a baseball program.

The counting circuit shown by 7 in Figure 3 starts counting horizontal scanning pulses in relation to the start pulse, stops counting in relation to the end pulse, and displays the number of horizontal scanning pulses during that time. It consists of a gate circuit, an OR circuit, a bistable multivibrator, a differential circuit, etc. It has a simple configuration that can be easily designed using well-known technology, so its illustration has been omitted, but its operation will be explained below. An example will be explained with reference to the waveform diagram in FIG.

A in the same figure shows a start pulse and a pulse signal having the timing of a pulse signal obtained by capturing and specifying the desired measurement start and end points of a moving object image displayed on the television screen and photoelectrically converting the image. It indicates the end pulse, and for example, when a light pen is used as the capture designation means, it is the output pulse of the light pen. b is the field pulse train of the additional image pickup tube M shown in FIG. 2, and c
is the output waveform of a bistable multi whose start pulse is the set pulse of a and the end pulse is the reset pulse, f and g are the differential waveforms of the output waveform, and d is obtained by gating the field pulse of b with the signal of c. This is a field pulse train between a start pulse and an end pulse, and the number of fields in a measurement period is selected by this.

e is a pulse counted down from the signal of d to the field repetition number of the slow motion image,
Let's say that the number of repetitions is m. If the television screen to be measured has a slow motion image obtained by repeating the field 10 times, then m = 10 and d.
This is a pulse that is counted down to 1/10 of the pulse. h is a pulse train created by ORing the pulse of e obtained in this way with the start pulse shown in a or g, and i is the differential pulse of g that has the timing of the pulse of b and the end pulse of a or its edge pulse. With the created reset pulse train, when the bistable multi is operated using the pulse h as the set pulse and the pulse i as the reset pulse, j
A pulse like this is obtained.

In this j pulse train, pulses 1 to 4
corresponds to the number of fields of standard television while the moving object image to be measured is moving,
The period A of pulse 1 and pulse B correspond to the time during which the mobile image is moving in its first and last fields.

By using the thus obtained pulse j as a gate pulse and counting the horizontal scanning pulses at the standard horizontal scanning frequency of the television signal guided to the monitor 5 in FIG. 3, the television screen displayed on the monitor 5 can be counted. The moving time of the moving object in can be expressed by the number of pulses in the horizontal scanning period.

If we consider the image of a moving object on a television screen to be a ball thrown by a baseball pitcher, the image of the moving object at the time the ball leaves the pitcher's hand and at the time the catcher catches the ball is displayed on the slow-motion television screen, for example. If the number of horizontal scanning pulses between the start pulse and end pulse obtained by instructing capture with a light pen is p, then the actual distance between the pitcher and catcher in baseball is almost constant. If this is l, then the speed of the ball is: (i) The time it takes for the ball to travel from the pitcher to the catcher =
0.06356P (msec) (ii) Ball speed = l/0.63556P (msec) Measured by:

In the example of baseball, the time it takes for the ball to reach the catcher from the pitcher is said to be 0.41 to 0.43 seconds, and in standard television, the highest time frequency is 1/
Since the time is 60 seconds, that is, 0.0167 seconds, it is impossible to express the difference in speed between pitchers, but since the method of the present invention counts horizontal scanning pulses, it can be measured to the extent that the difference in speed is sufficiently visible. As shown in the example, since the image of the moving object to be measured is displayed on the television screen, the image is slow-motioned by a factor of n.
The improvement in measurement accuracy resulting from the ease of capturing and indicating the measurement start and end points is significant.

For example, if the number of fields on the measured television screen is 4 times that of standard television, that is, 4 times the actual movement of the subject, it is 0.0042 seconds, and if it is 8 times the number of fields, it is 0.0021 seconds. It can be measured with an accuracy of seconds.

On the other hand, if the multiple is increased, the vertical resolution of one field image will drop sharply, but in this case, the horizontal scanning frequency of the additional image pickup tube indicated by M in Fig. 3 should be Horizontal scanning frequency), for example, 2fh when n=4 and √8fh3fh when n=8 to balance the horizontal and vertical resolutions.

In addition, when broadcasting live broadcast programs such as baseball, the camera operates at a horizontal scanning frequency √fh and a vertical scanning frequency nfv in conjunction with the drive system of the imaging camera, as shown in Figure 7a, separately from the general imaging camera. An independent television camera is installed so that the catcher and pitcher are fixed at predetermined positions on the television screen, and the vertical scanning speed of the pitcher and catcher is slowed down as shown in Figure 7b. In order to increase the vertical resolution of the part where the ball leaves the pitcher and the part where the ball is caught, the camera is driven vertically with a vertical scanning waveform as shown in FIG. If measurement is performed on a television screen, highly accurate measurement results can be broadcast immediately during live broadcasts, which can be expected to further improve broadcast effectiveness.

As described above, according to the method of the present invention, the speed, flight time, etc. of a high-speed moving object on a television screen can be measured directly from the screen with high precision. In addition, by replacing the television screen with a slow-motion screen, not only the measurement accuracy is greatly improved, but also the television signal reproduced as the television screen has a faster pulse rate for driving the imaging system. If the signal is obtained from a means that can generate a wide band signal in the time frequency domain by simply changing the signal, the characteristics of the wide time frequency band can be utilized, and measurement accuracy can be further improved.

Therefore, for example, it is possible to instantly measure the pitch of a pitcher's ball, the speed of a home run ball, and the running time of a runner in a live baseball broadcast program, etc., so that the measurement results can be used in slow motion on the broadcast program. It can also greatly contribute to the effectiveness of a program, such as by displaying it in combination with video.

[Brief explanation of the drawing]

FIGS. 1 and 2 show the configuration of an imaging system for explaining a television signal reproduced as a television screen according to the present invention.
The figure is a conventional configuration diagram, and FIG. 2 is an embodiment configuration diagram for the present invention. FIG. 3 shows an example in which the present invention is implemented in an imaging system. FIG. 4 and FIG. 5 are explanatory waveform diagrams of the embodiment, respectively. FIG. 6 is an explanatory diagram of the operation of the counting circuit in FIG. 3. FIG. 7 is an explanatory diagram of another embodiment of the television screen according to the present invention. 1 is a three-color separation system, 2 is a head amplifier, 3 is a processing amplifier, 4 is a memory device, 5 is a monitor, 6 is a light pen, 7 is a counting circuit, M is an additional image pickup tube, and fv is a vertical scanning frequency (field period). ),
fh is horizontal scanning frequency.

Claims (1)

[Scope of Claims] 1. Imaging a moving object by increasing the vertical scanning frequency of an image pickup tube for measuring the moving speed of a moving object than that of an image pickup tube for television broadcasting, and once recording the imaged signal, By capturing and specifying the desired measurement start and end points of the moving body displayed on the television screen based on the slow-motion television signal obtained by lowering the vertical scanning frequency on that screen and photoelectrically converting them. , obtain pulse signals with timings corresponding to the positions of these two points on the television screen, and count the horizontal scanning period during a considerable period between these pulse signals before the slow motion is made, thereby obtaining the desired measurement. A method for measuring the moving speed of a moving object on a television screen, characterized in that the moving speed of the moving object can be measured by determining the moving time from a starting point to an ending point. 2. A slow motion television signal captured by reducing the vertical scanning speed in the vicinity of the desired measurement start point and end point is reproduced, and this is used as the television screen. A method for measuring the moving speed of a moving object on a television screen as described above.