JP2582354B2 - Image information processing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image information processing apparatus, and more particularly to an apparatus for processing image information captured under specific conditions.

[Related Art] Conventionally, as such an apparatus, there is a monitoring system. This is, for example, a combination of a television camera using a solid-state imaging device or the like and a magnetic recording / reproducing device that constantly records an output video signal of the television camera. Such systems are used for frequent human traffic at all times, for example, for monitoring the inside of a bank during business hours.

[Problems to be Solved by the Invention] However, such a system configured to constantly record the output video signal of the television camera is used, for example, in a place where there are many people during the day but there is no traffic at night, Applying it to a place with little traffic even during the day is not economical and space disadvantageous. Therefore, Japanese Patent Application Laid-Open
No. 81621 discloses an inspection device that records only when a movement of a subject is detected. However, in such a monitoring device, there is a problem that even if there is no movement of the subject, the noise is also affected by the screen noise, and recording is performed in an unnecessary portion.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks of the conventional apparatus and to provide an apparatus for supplying image information only when a motion of a subject is detected under specific conditions.

[Means for Solving the Problems] The present invention compares an image signal of a subject obtained from an image sensor with an image signal of a predetermined period before, and
Detecting means for detecting the movement of the subject, supplying means for supplying image information based on the image pickup signal to a recording medium, and the detecting means whereby the movement of the subject is obtained at a predetermined frequency or more and continuously for a predetermined period. And control means for controlling the supply means to supply the image information to the recording medium when the image information is received.

[Operation] According to the present invention, the image information is supplied to the recording medium when the motion of the subject is obtained by the detection means at a predetermined frequency or more and continuously for a predetermined period.

Examples Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a monitoring recording apparatus to which the present invention is applied.

In FIG. 1, reference numeral 1 denotes an optical system, and 2 denotes an image pickup device which enters through the optical system 1 and photoelectrically converts a subject image. Reference numeral 3 denotes an amplifier that amplifies an image signal from the image sensor 2. 4
Is a signal processing circuit for separating the imaging signal from the amplifier 3 into a luminance signal Y and a chrominance signal C. Reference numeral 5 denotes a recording signal processing circuit for converting the luminance signal Y and the color signal C into a format suitable for recording. Reference numeral 6 denotes a recording amplifier for amplifying an output signal of the recording signal processing circuit 5, reference numeral 7 denotes a magnetic head, and reference numeral 8 denotes a recording magnetic sheet. 9 is a drive motor for rotating the magnetic sheet 8, 10 is a PG head for generating a PG pulse for detecting the rotation phase of the magnetic sheet 8, and 11 is an amplifier for amplifying the PG pulse from the PG head 10. . Reference numeral 12 denotes a motor drive circuit which drives the drive motor 9 and controls the rotation phase by the PG pulse from the amplifier 11. The PG pulse is also supplied to the control circuit 15 and used as a reference pulse of the system.

Reference numeral 13 denotes an image sensor driving circuit for driving the image sensor 2, which scans the image sensor 2 horizontally and vertically. Reference numeral 14 denotes a motion detection circuit which detects the motion of the subject based on the inter-frame difference signal in the luminance signal Y from the camera signal processing circuit 4. Reference numeral 15 denotes a control circuit, which has a CPU and storage means for executing control as described later. A head driving circuit 15A controls the movement of the head 7 in the radial direction of the sheet 8, the floating of the head 7, and the contact with the sheet 8.

FIG. 2 is a block diagram showing the configuration of the motion detection circuit 14.

Reference numeral 16 denotes a sample hold circuit which samples and holds the luminance signal Y from the camera signal processing circuit 4. The sampling of the image in the sample hold circuit 16 is performed as shown in FIG.

That is, as shown in FIG.
Samples and M samples are extracted in the vertical direction, and data of a total of NM sample points are sampled as data of one screen.

For example, even when an 8 Kbyte memory is used, 8000 points of data can be taken out on one screen.

Reference numeral 17 denotes an A / D conversion circuit, which is a sample and hold circuit 16
Is quantized according to the level of the analog data signal, and is converted into, for example, an 8-bit digital signal.

A memory 18 stores the digital signal from the sample hold circuit 16 for one frame period.

Reference numeral 19 denotes a difference circuit, which is a digital signal from the A / D conversion circuit 17 and 1 which is read from the memory 18 in the order of writing.
A difference is detected for each sample point at the same position on the screen with respect to the digital signal before the frame. Reference numeral 20 denotes an integrating circuit, which integrates the difference value for each sample point from the difference circuit 19 for each frame period. As shown in FIG. 3, the level value of the sampling point of the current frame is V (i, j), 1
The level value of the sampling point before the frame is V ′
If (i, j) (the i-th in the horizontal direction and the j-th in the vertical direction), in the integrating circuit 20, The calculation of the calculation value S is performed by

Reference numeral 21 denotes a threshold circuit, which determines whether or not the integrated value S is equal to or greater than a predetermined value. If the integrated value S is equal to or greater than the predetermined value, it determines that there is movement on the screen and inputs a detection signal to the control circuit 15. .

 The control circuit 15 performs control as shown in FIG. 4, for example.

In step S1, the image sensor 2 is driven to drive the threshold circuit 21.
And waits until a motion detection signal is output at a frequency equal to or higher than a predetermined value and continuously for a predetermined period. When the motion detection signal is output, the process proceeds to step S2, where the magnetic sheet 8 is rotationally driven.

When a motion is detected, since an image signal must be recorded promptly, an excessive current is applied to the drive motor 9 instantaneously.

Next, in step S3, the magnetic head 7 is brought into contact with the magnetic sheet 8 to bring it into an on-track state.

Then, the process proceeds to step S4, and waits until a signal that detects a state in which recording is enabled by the phase control is output from the motor drive circuit 12, and if output, the step is performed.
Proceed to S5. In step S5, the charge stored in the image sensor 2 for one frame period is read.

Next, in step S6, the read signal is separated into a luminance signal Y and a chrominance signal C by the camera signal processing circuit 4 and is recorded on the magnetic sheet 8 by the recording signal processing circuit 5 in a format suitable for recording.

Then, the process proceeds to step S7, and the magnetic head 7 is levitated so as to be in a non-contact state with the magnetic sheet 8. Next, in step S8, the rotation of the magnetic sheet 8 is stopped. Next, in step S9, in order to perform continuous recording, the elapse of a predetermined time for obtaining a preset time interval is waited, and after the elapse of the predetermined time, the process returns to step S1 to detect a motion.

FIG. 6 is a flowchart showing another operation of the control circuit 15. FIG. 5 shows an operation timing chart. FIG. 5 (A) shows the charge readout timing from the image sensor 2, which coincides with the motion detection timing. Here, the video signal one frame before,
The motion of the image is detected from the difference from the video signal of the current frame.

FIG. 5B shows an output signal from the motion detection circuit 14. When it is determined that the integrated value of the difference between one frame is larger than the threshold value of the threshold circuit 21 and there is movement, the level “1”
Is output, and when it is determined that there is no motion because the integrated value is smaller than the threshold value of the threshold circuit 21, a level “0” is output.

As shown in FIG. 6, first, in step S21, the image sensor 2 is driven to form an image signal. Next, in step S22, the magnetic sheet 8 is driven to rotate, and the speed control and the phase control are performed to make a recordable state.

Next, in step S23, it is determined whether or not a motion is detected based on a signal output from the motion detection circuit 14. That is, it is determined whether the level "1" signal shown in FIG. 5B has been output. If there is an output of level “0”, that is, if no motion detection has been performed, the process proceeds to step S24 to reset a motion continuation counter described later. On the other hand, if there is a motion detection in step S23, that is, if there is an output of level “1”, step S2
Proceed to 4 to increment the motion continuation counter by one. This motion continuation counter is carried out, for example, when motion is continuously detected over a predetermined R frame. That is, a release pulse A as shown in FIGS. 5 (C) and (E) is output.

Next, in step S26, it is determined whether or not the continuous motion counter value has reached a predetermined value R. If the value has not reached the predetermined value R, the process returns to step S23. Therefore, when the motion detection is lost and the output becomes "0" before the predetermined value R is reached, the process proceeds to step S24, where the motion continuation counter is reset.

If the predetermined value R has been reached in step S26, the motion continuous counter is reset in step S27. Next, in step S28, the release pulse A shown in FIG. 5C is supplied from the control circuit 15 to the recording signal processing circuit 5, and the recording operation is started. Predetermined value R of FIG. 5 (C) the motion continuity counter indicates the case where it is set to 2, the motion detection pulses obtained at time t ₄ and t ₅ in FIG. 5 (A) (5 A release pulse A shown in FIG. 5B and FIG. 5C is output. Recording operation for one frame period from time t ₅ as shown in FIG. 5 (D) (Time
t _{4 to} t ₆ ).

Then from time t ₅ the release pulse A is output in step S29, (3 frame periods in the example of FIG. 5) Continuous limit interval T of the recording apparatus determines whether has elapsed. If the continuous shooting limit interval T has not elapsed, step S30
It is determined whether or not the motion has been detected again. For example, time
Reset the motion continuity counter value in step S31 if no motion ( "0" output) is detected in t _7, the flow returns to step S29. In step S30, for example, the time
When motion detection is performed during the continuous shooting limit interval T after the release as t ₁₁ and t ₁₂ is incremented by one movement continuation counter advance to step S32.

Next, in step S33, it is determined whether or not the counter value has reached a predetermined value R. If the counter value has not reached the predetermined value R, the process returns to step S29. If the counter value has reached the predetermined value R (because the head is being accessed and recording cannot be performed), the process returns to step S34. Turn on the recording flag (REC flag),
Thereafter, the flow returns to step S29 to determine whether the continuous shooting limit interval T has elapsed. If it is determined in step S29 that the continuous shooting limit interval T has elapsed, it is determined in step S35 whether the REC flag is ON. If REC flag ON, and resets the flag in step S36, the process returns to step S27, and outputs a release pulse A as a time t ₁₃ shown in FIG. 5 (C), the recording operation is performed. On the other hand, if the recording flag is OFF in step S35, the process returns to step S23.

It should be noted that the period in which carried out the REC flag control, the time t ₁₀ ~
a t _13. That is, as shown in FIG.
Starts the recording operation at _10, the movement is detected at time t ₁₁ and t ₁₂ before continuous limit interval T has elapsed, the recording flag is turned ON at time t _12. And the time when the interval T has elapsed
recording as shown in FIG. 5 (D) is started t _13. In this case, the video signal to be recorded are those read out one frame period into the signal charges accumulated in the imaging device 2 at time t ₁₂ ~t _13.

FIG. 5E shows the generation timing of the release pulse A when the predetermined value R of the motion continuous shooting counter is set to 3, and FIG. 5F shows the timing of the recording operation. At this time, since the predetermined value R becomes equal to the continuous shooting limit interval T, it goes without saying that the setting of the recording flag after step S29 in FIG. 6 becomes unnecessary.

Further, the control circuit 15 performs control as shown in FIG. 7, for example. FIG. 8 shows an operation timing chart.

As shown in FIG. 7, first, in step S41, the image sensor 2 is driven to form an image signal. At this time, the recording system including the magnetic sheet is not operating. Then steps
In S42, a motion detection counter described later is reset to 0.

Next, in step S43, it is determined whether or not a motion is detected based on a signal output from the motion detection circuit 14. If the motion is detected, the motion detection counter is incremented by one in step S44, and it is determined that the possibility of recording is increased, and the magnetic sheet is rotationally driven in step S45,
Proceed to step S46. The motion detection counter is decremented by a decrement pulse (FIG. 8 (C)) output at regular intervals. Therefore, the increment operation of the motion detection counter is suppressed by the decrement pulse, and as a result, only motion detection at a certain frequency or more can be counted by the motion detection counter. In this embodiment, when the motion detection is performed to some extent, the magnetic sheet is driven to rotate, and a preparation operation for recording is performed.

If no motion is detected in step S43, the process proceeds directly to step S46. In step S46, it is determined whether or not a decrement pulse has been output.
In step S17, the motion detection counter is decremented by 1 and step S
Proceed to 48. On the other hand, when the decrement pulse is not output in step S46, the process directly proceeds to step S48.

In step S48, it is determined whether the count value of the motion detection count has reached a predetermined value.
In step 9, it is determined whether the count value of the motion detection counter is 0.
If not, the process returns to step S43. If it is 0, the process returns to step S50.
To stop the rotation driving of the magnetic sheet and return to step S43. If the count value of the motion detection counter has reached the predetermined value in step S48, it is determined in step S51 whether or not recording is possible based on the rotation speed of the magnetic sheet, the phase state, and the like. For example, in step S52, the release pulse (FIG.
To start the recording operation.

Next, in step S53, it is determined whether a continuous shooting limit speed or a preset interval recording interval T has elapsed since the release pulse was output, and if it has elapsed, the process returns to step S43. For example, it is determined in step S54 whether a decrement pulse has been output, and if it has been output, the motion detection counter is decremented by one in step S55, and the process returns to step S53. If no decrement pulse is output in step S54, the process returns to step S53. As described above, the increment operation of the motion detection counter is not performed at all until the predetermined time T elapses after the recording operation is performed in step S52. Also, by not resetting the count value of the motion detection counter to 0 immediately after the recording, the recording operation can be performed immediately when the motion detection is performed again at a predetermined frequency or more after a predetermined time T has elapsed after the recording. Can be.

While the predetermined time T has passed in steps S53 to S55, the decrement operation of the motion detection counter was performed every time the decrement pulse was detected. However, since the time T and the generation cycle of the decrement pulse are known, the predetermined time T Needless to say, the number of decrement pulses generated during T may be decremented at once after the elapse of the predetermined time T, and the process may return to step S53.

Next, a schematic operation waveform of the flowchart of FIG. 7 will be described with reference to FIG.

That is, (A) shows the readout timing of the image sensor, that is, the motion detection timing, which is, for example, one frame period.

(B) is an output signal of the motion detection circuit 14, where "0" indicates no motion detection and "1" indicates the presence of motion detection.

(C) is a decrement pulse, which is output once every three frames. Therefore, when the motion is detected at a frequency lower than this, the motion detection counter value keeps a zero value.

(D) is a count value of the motion detection counter, which is incremented by the motion detection output (B) and decremented by the decrement pulse (C).

(E) is a release timing pulse detected and output when the motion detection counter value reaches a predetermined value, in this case, 5.

(F) is a recording timing, which is one frame after the release pulse.

(G) is a magnetic sheet rotation drive control signal. While this signal is "H", the rotation speed and phase servo are performed.

(H) is a signal indicating a recordable state, which becomes "H" output when the rotation control of the magnetic sheet is completed and the recordable state is reached.

As shown in FIG. 8, the motion detection counter incremented by one at time t1 is decremented by one again by a decrement pulse (C) at time t2 and returned to a zero value. Then, counting is started again at time t3. Since the motion detection output has a predetermined frequency or more, the count value gradually increases while being decremented by 1 by the decrement pulse (C), and reaches the set value 5 at time t5. And the release pulse (E) is output. Since the recordable state is obtained at time t4, recording is performed between times t5 and t6 by the release pulse. When the release pulse is generated, it waits for a predetermined time T for continuous shooting recording to elapse, and the counter value is decremented only by the decrement pulse (C) without accepting the motion detection pulse generated during this time.

The state returns to the original state again at time t7, and a release pulse is output at time t8 according to the same algorithm.
Completes the recording.

In the above example, the sample points are uniformly distributed on the screen. However, it is also possible to provide the sample points only in the central part or to increase the sampling density in the central part as compared with the peripheral part.

Furthermore, although the threshold circuit of the motion detection circuit is fixed, the invention is not limited to this, and if it is variable, it becomes resistant to noise and can be used in different environments.

Although the level change of the luminance signal is used for motion detection, the present invention is not limited to this, and a color signal level or hue change may be used.

It is not limited to performing motion detection over one frame, and it goes without saying that motion detection may be performed for each field in an image sensor for field reading.

Although a magnetic sheet is used as a recording medium, the present invention is not limited to this, and an optical disk, a magnetic tape, a semiconductor memory, or the like may be used.

The period during which a video signal for one screen is obtained is defined as one frame period (1/30 second) of an actual television signal.
The information of one screen may be obtained by sampling a part of the screen over several frames according to the processing situation of the arithmetic circuit or the like.

In order to reduce the amount of data, the amount of motion was detected only at a plurality of points on the screen. However, a one-frame delay signal was constantly compared with the current signal using a frame memory, and the level difference was detected by a predetermined amount. Sometimes it may be determined that there is movement.

The number of magnetic sheets is one, but if the capacity is insufficient, a plurality of sheets may be prepared. Further, in the present embodiment, the imaging device and the recording device are considered as an integral unit. However, an imaging device configured as a separate body and a device that records a signal obtained from the imaging device is also included in the present invention. Of course it is.

[Effects of the Invention] As described above, according to the present invention, a detection unit that detects a movement of a subject by comparing an imaging signal related to a subject obtained from an imaging device with an imaging signal before a predetermined period is provided. Supply means for supplying image information based on the image pickup signal to a recording medium; and supply of the image information when the movement of the subject is obtained by the detection means at a predetermined frequency or more and continuously for a predetermined period. Means comprising control means for controlling the supply to the recording medium, by saving the recording medium for supplying image information to the recording medium only when continuous movement of the subject is detected, Further, when the recorded image information is reproduced, it can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a block diagram of a motion detection circuit in the embodiment, FIG. 3 is a diagram showing sample points on one screen, FIG. 4, FIG. FIG. 7 is a flowchart showing an operation example of the embodiment, and FIGS. 5 and 8 are operation timing charts of respective parts of the embodiment. 2 ... image sensor, 14 ... motion detection circuit, 15 ... control circuit.

Claims (1)

(57) [Claims] 1. A detecting means for detecting a movement of a subject by comparing an imaging signal of a subject obtained from an imaging device with an imaging signal of a predetermined period before, and a recording medium for storing image information based on the imaging signal. Supply means for supplying the image information to the recording medium when the movement of the subject is obtained by the detection means at a predetermined frequency or more and continuously for a predetermined period. An image information processing apparatus comprising: