JP2632841B2 - Image evaluation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image evaluation device, and more particularly, to an image evaluation device that detects and evaluates a change state of an input image and outputs the result to the outside.

[Conventional technology]

Conventionally, a screen total luminance value is taken out from an output signal of an image input device such as a TV camera and stored, and the stored past total luminance value is compared with a currently input total luminance value, and a difference between the two is determined in advance. An image evaluation device that outputs a warning signal or the like to the outside when the value is equal to or more than a set predetermined value is provided.
This type of device can easily evaluate and detect screen changes,
For example, it is widely used in security cameras, process control monitoring devices, and the like.

[Problems to be solved by the invention]

However, in such a conventional apparatus, since the screen is evaluated by comparing only the past value (total screen brightness value) one predetermined period before and the current value, the speed of the motion is fast. However, there is a disadvantage that the sensitivity to both slow and slow ones cannot be improved.

The present invention has been made in view of the above points, and an object of the present invention is to provide an image evaluation device capable of always appropriately detecting the presence or absence of a movement regardless of the movement of a subject.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an image input means for capturing an image of a moving subject at a predetermined cycle (a in FIG. 1).
Storage means (b in FIG. 1) for storing image information obtained in the predetermined cycle from the image input means; image information of a plurality of previous cycles stored in the storage means and a new image The movement of the subject is detected by comparing the information with the information (S5 in FIG. 3), and the change of the new image information with respect to the image information before the predetermined plurality of cycles is larger than a predetermined first amount (L1). In the first mode in which it is detected that the value is larger, a warning is issued (S13 in FIG. 3) when the first mode continues for one period (P1) (S7 in FIG. 3), and the comparison is performed. Therefore, the change of the new image information with respect to the image information before the predetermined plurality of cycles is smaller than the first amount and larger than a predetermined second amount (L2) (first amount> second amount). Is detected in the second mode, the second mode is in the second period (P2) ( A warning to the first time period <When the second period) is continued (S9 of FIG. 3) (of FIG. 3 S1
3) a comparison control means (c in FIG. 1) for performing control as described above.

[Operation] In the present invention, since the configuration is as described above, stable motion detection without malfunction can be performed even when the motion of the moving subject is large or small.

〔Example〕

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

FIG. 1 shows a basic configuration of an embodiment of the present invention. In this figure, a is an image input means for capturing an image of a moving subject at a predetermined cycle, and b is a storage means for storing image information obtained from the image input means a at the predetermined cycle. c is comparison means (corresponding to the comparison control means in the claims);
The motion of the subject is detected by comparing the image information of a plurality of previous cycles stored in the storage means b with the new image information, and the change of the new image information with respect to the image information of the predetermined plurality of previous cycles. Is greater than a predetermined first amount (L1), a warning is issued if the first mode continues for a first period (P1), and the above-mentioned comparison indicates that It is detected that the change of the new image information with respect to the image information of a predetermined plurality of cycles before is smaller than the first amount and larger than a predetermined second amount (L2) (first amount> second amount). In the second mode performed,
When the second mode continues for the second period (P2) (first period <second period), control is performed so as to issue a warning. d is output means for outputting the warning.

FIG. 2 shows a circuit configuration of an embodiment of the present invention. In this figure, 1 is an image input device having an imaging camera, 2 is a ROM (read only memory) in which a control procedure as shown in FIG. 3 according to the present invention is stored in advance, and 3 is an arithmetic control according to the control procedure and a central processing unit having an analog, digital conversion means and the counter C _1, C _2, C _3, etc. (CP
A microcomputer as U), a RAM (random access memory) 4 for temporarily storing data and the like, and a buzzer 5 for outputting a warning sound under the control of the microcomputer 3.

An optical image is input by the image input device 1, and all luminance signals in an image of one field or luminance signals of a window portion set in advance are integrated and transmitted to the microcomputer 3. Microcomputer 3
Then, the integrated signal from the image input device 1 is converted from analog to digital (A-D) and input, and is sequentially updated and stored in the RAM 4. At the same time, a plurality of data stored in the past, that is, data several fields before, The current input data (digital value obtained by integrating the luminance value) is sequentially compared, and if there is a data whose difference between the two has changed by a certain value or more, the buzzer 5 is turned on, and a buzzer sound for warning is issued. 6 is buzzer 5 ON
When the buzzer 5 is turned off and the sound is
This is a manual switch for resetting to clear AM data.

Next, an example of the operation of the apparatus according to the embodiment of the present invention shown in FIG. 2 will be described in detail with reference to the flowchart of FIG. 3 and the explanatory diagram of FIG.

First, in step S1, it is determined whether the buzzer 5 is ON.
When the buzzer 5 is off, the data from the image input device 1 (integrated digital data of the luminance value) is stored in the RAM 4 by repeating the processing of steps S2, S3 and S4 until the data is full.

When digital data for the luminance value for a predetermined number of fields is stored in a predetermined area of the RAM 4,
Since the affirmative determination that the RAM 4 is full is made in S3, the process proceeds to the next data comparison / determination process in step S5.

Processing in step S5, as shown in FIG. 4, the field rank N _1, N _2, N ₃ is _{N 1 <N 2 <N 3} , a predetermined value l _1, l _2, l ₃ is l ₁
> L _2> in l _3, the difference between the stored data and the current input data before N _i fields in the RAM 4 D _i (where, i = 1, 2, 3)
When D _i > l ₁ , the process proceeds to step S6 described below as determination mode 1, and when l ₁ ≧ D _i > l ₂ , determination mode 2
Then, the process proceeds to step S16 to be described later. If l ₂ ≧ D _i > l ₃ , the process proceeds to step S17 to be described later as the determination mode 3, and D _i ≦ l ₃
In this case, the process proceeds to S18 described below as the determination mode 4.

First, in the mode 1 (D ₁ > l ₁ or D ₂ > l ₁ or D ₃
> The l _1), a first value of the internal counter C ₁ proceeds from step S5 to step S6 to increment by +1 or the value of the counter C ₁ in the next step S7 reaches the predetermined value P ₁ Determine whether or not. P ₁ represents the number of occurrences of the same mode (generation time), the relationship between the occurrence count P _2, the number of occurrences P ₃ Mode 3 Mode 2 described later is set to P ₁ <P ₂ <P _3. If the state of the mode 1 is followed by _one P goes to step S13 described later, the step S7 if not reaching _one P advances to step S8 becomes negative determination.

In step S8 the second value of the internal counter C ₂ is incremented by +1, the counter C ₂ in the next step S9
Values go to step S13 to be described later When a positive determination is made by determining whether it has reached a predetermined value P _2, step S if negative determination
Proceed to 10.

In step S10 the second value of the internal counter C ₃ is incremented by +1, described later When a positive determination value of the counter C ₃ in the next step S11 determines whether it has reached a predetermined value P ₃ If the determination is negative, the process proceeds to the next step S12, where the latest data input in step S2 is stored in the RAM 4 at the address where the oldest data is stored, and the process returns to step S2.

If any of steps S7, S9, and S11 is affirmatively determined, the process proceeds to step S13 to turn on the buzzer 5.
Then, the process returns to step S1. At this time, since an affirmative determination is made in step S1, the process goes to step S14 and waits until the manual switch 6 is pressed. When the switch 6 is pressed, the buzzer 5 is turned off in step S15 to mute the sound and the RAM 4
After clearing all the data, the process returns to step S1.

That is, in the mode 1 shown in FIG. 4, since the degree of image change is the strongest, the state of the mode 2 and the mode 3 described later is included. Therefore, in this mode 1, the contents of the counters C ₁ , C ₂ and C ₃ are C ₁ = P ₁ or C ₂ = P ₂ or C ₃ =
Until P _3, the counter C _1, C _2, C ₃ of values by respectively adding +1 increments, it rewrites the oldest data RAM4 with the latest input data, the subsequent counting
When any one of the conditions C ₁ = P ₁ , C ₂ = P ₂ , C ₃ = P ₃ is satisfied, the buzzer 5 is turned on, and the warning sound is generated until the switch 6 is pressed.

Also, in the mode 2 shown in FIG. 4, that is, l ₁ ≧
When D ₁ > l ₂ , or l ₁ ≧ D ₂ > l ₂ , or l ₁ ≧ D ₃ > l ₃ , the degree of image change is a state following mode 1 and includes mode 3, so steps S5 to S16 Go to the first
After clearing the counters C ₁ to zero, the process proceeds to step S8 mentioned above, the predetermined value P ₂ value of the counter C ₂ or counter C _3,
Values until reaches a predetermined value P ₃ (step S9, S11), the counter C _2, C ₃ values respectively by adding +1 (step S8, S1
0), after rewriting the oldest stored data of the RAM 4 with the latest input data (step S12), returns to the data input of step S2, and thereafter, the counters C ₂ and C ₃ read C ₂ = P ₂ or C ₃
= When it reaches the P ₃ buzzer 5 is turned ON at step S13, the flow returns to step S1.

Similarly, in the mode 3 shown in FIG. 4, that is, l ₂ ≧
When D ₁ > l ₃ or l ₂ ≧ D ₂ > l ₃ , since the degree of image change is weak in mode 2, steps from step S5
Proceed to S17 in aforementioned counter C _1, after clearing C ₃ to each zero, until the value of the counter C ₃ reaches a predetermined value P _3, that counter C ₃ to +1 is added (step S10), RMA4 rewrites the latest data entered the oldest stored data (step S12), the process returns to the data input process in step S2, it turns oN the beeper 5 in step S13 when the subsequent counter C ₃ has reached C ₃ = P _3, It returns to step S1.

Further, in the mode 4 shown in FIG. 4, that is, D ₁ ≦ l ₃
Or, when D ₂ ≦ l ₃ or D ₃ ≦ l, there is no change in the image for a predetermined time, and all zeros of the _first to third counters C ₁ , C ₂ , C ₃ are cleared. Thereafter, the process returns to the data input process in step S2, and the above-described data input process and the like are repeated.

As described above, when the difference D _i by comparing multiple stored data and the latest input data described above are most greater large value l ₁ of a predetermined value determined with multiple, in this example (mode 1)
Uses the smallest period P ₁ of a plurality of defined time period,
If the difference D _i according to the above comparison is between the smallest value l ₃ and the next small value l ₂ of a predetermined value determined with multiple (Mode 3), the greatest period of several defined period P _{Since the} image evaluation is performed by using ₃ , the sensitivity to both fast and slow moving objects can be appropriately increased.

〔The invention's effect〕

As described above, according to the present invention, regardless of the magnitude of the motion of a moving subject, stable motion detection with few malfunctions can be performed, so that a highly reliable monitoring system or the like can be obtained.

[Brief description of the drawings]

1 is a block diagram showing a basic configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing a circuit configuration of the embodiment of the present invention, and FIG. 3 is a flowchart showing an operation example of the embodiment of the present invention in FIG. FIG. 4 is a table showing the contents of the data comparison process in step S5 of FIG. 1 ... image input device, 2 ... ROM, 3 ... microcomputer, 4 ... RAM, 5 ... buzzer, 6 ... switch.

Claims (1)

(57) [Claims] 1. An image input means for picking up an image of a moving subject at a predetermined cycle, a storage means for storing image information obtained from the image input means at the predetermined cycle, and a predetermined information stored in the storage means. The movement of the subject is detected by comparing the image information of a plurality of cycles before and the new image information, and a change of the new image information with respect to the image information of the predetermined plurality of cycles is smaller than a predetermined first amount. In the first mode in which it is detected that the image information is larger than the first mode, a warning is issued when the first mode continues for the first period. In the second mode in which the change is detected to be smaller than the first amount and larger than a predetermined second amount (first amount> second amount), the second mode is the second mode.
And a comparison control means for performing control so as to issue a warning when the period (first period <second period) has continued.