JP3490196B2 - Image processing apparatus and method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and method for detecting only a moving object to be detected in an arbitrary image.

[0002]

2. Description of the Related Art As a method for detecting a moving object in a video image captured by a TV camera or the like, the conventional simplest method is to obtain a difference between a plurality of continuously captured images, or in advance. There is a method of obtaining the difference between the created background image and the current image.

A method of detecting a change due to a moving object based on the difference calculation between these images is, for example, an image monitoring device using an image pickup device such as a fixed TV camera, and the like. It is used in devices for detecting intruders and intruders.

By the way, in the moving object detection method based on such difference processing, it is a premise that there is no environmental change other than the intruding object in the monitored area. Has the drawback of falsely detecting.

For example, when an environment with large fluctuations, such as outdoors, is to be monitored, only a part of the contour of a moving object can be detected, or an intruding object cannot be detected due to fluctuations in illumination intensity due to weather changes, etc. Fluctuations of trees due to wind and diffuse reflection of sunlight on the water surface cannot be detected separately from intruders, and it is very difficult to improve the detection accuracy of moving objects.

When a video image that does not include a moving object to be detected, that is, a reference video image (background video image) can be prepared in advance, as a method for avoiding erroneous detection due to environmental changes, see Reference 1 “Maeda, Tanaka, Shio, Ishii: Object extraction method using distribution in multi-dimensional luminance space, Technical report of IEICE pattern recognition and understanding PRU91-68 pp.67-7
4 ", Reference 2" Sato, Mase, Suenaga: Robust Object Extraction Method from xt Spatiotemporal Images, Proceedings of the 1991 IEICE Fall National Conference D-198 (6-200) ", References 3 "KANETA, KANOH, KANEMARU, NAGAI: Image Processing
Method for Intruder Detection around Power Line To
wers, proc.of 1992 IAPR Workshop on Machine Vision
Applications (MVA'92) pp.353-356 ", Reference 4" Nakai: Japanese Patent Application No. 6-175492, Image Change Detection Device "are known.

In these methods, a statistical feature amount in a space or a time domain set for each pixel in an image is obtained and compared with that of a reference pixel to mainly measure the illumination intensity. It aims to realize object detection that is not affected by environmental changes that occur in a wide area within the screen, such as changes.

In particular, in the method described in Reference Document 4, not only environmental disturbances that occur over a wide range, but also image fluctuations that occur repeatedly in the monitoring area, such as fluctuations of trees and diffuse reflection of sunlight on the water surface, occur repeatedly. Therefore, a method has been proposed in which a disturbance and a moving object can be distinguished and detected by using a statistical discrimination method even for a disturbance that is easily mistakenly detected as a moving object to be detected.

In these four methods, it is necessary to prepare in advance a background image that does not include a moving object,
If this is impossible, accurate moving object detection is impossible.

Further, in the difference processing method between consecutive image frames, it is not necessary to prepare a background image, and it is not easily affected by the gradual change of environmental conditions due to changes over time, but at the normal frame rate. When the difference is calculated, only the contour portion of the moving object can be detected, or when the moving speed of the intruding object is low, it cannot be detected. To avoid this, if the time interval of the image frames to be captured is set to be long, it becomes possible to detect even the central portion of the moving object area, but this means that the image one frame before is prepared in advance as the reference image (background image). The difference is equivalent to the difference, and the false detection increases due to the influence of the environmental change. That is, if the difference in continuous frames is used while maintaining the advantage of being less susceptible to the influence of disturbance, only the contour portion of the moving object can be detected.

As described above, in the method of detecting a moving object such as an intruding object from a video image of a TV camera or the like, in order to avoid erroneous detection of environmental changes and disturbances and to accurately detect the image area of the moving object. However, in the above methods, it is necessary to prepare in advance a reference image (background image) that does not include a moving object and is captured under exactly the same conditions as the image for object detection. With this, when an object frequently enters the surveillance area or when environmental conditions such as the sunshine condition change gradually due to changes over time, such a reference image cannot be prepared and only moving objects can be prepared. It was impossible to detect accurately.

[0012]

As described above, in the conventional moving object detection method, in order to avoid erroneous detection of environmental changes and disturbances and to accurately detect the image area of the moving object, the object detection is performed. When it is necessary to prepare in advance a reference image (background image) that does not include moving objects, and was taken under the exact same conditions as the images to be performed, and environmental conditions such as sunshine conditions gradually change over time. Alternatively, when the reference image cannot be prepared in advance, it is impossible to accurately detect only the moving object.

The present invention has been made in consideration of such circumstances, and an object of the present invention is to prepare a background image by shooting a background image in advance when there is a disturbance such as environmental change in the surveillance area. It is an object of the present invention to provide an image processing apparatus and method capable of distinguishing and detecting only a moving object to be detected by updating the background image or the background probability distribution as needed.

[0014]

An image processing apparatus according to a first aspect of the present invention estimates a reference image in which only a background and a stationary object are captured from an image sequence in which a stationary object or a moving object is captured in the background. An image processing apparatus, which is capable of accumulating an image sequence in which a stationary object or a moving object is reflected on a background, and a feature amount of a specific area of each image in the image sequence accumulated in the image storage unit. The feature amount extraction means and the order of the feature amounts of the specific regions of each image calculated by the feature amount extraction means are rearranged from the order arranged based on the image sequence to the order based on the magnitude of the feature amount. From the feature quantity arrangement means and a plurality of feature quantities whose order has been rearranged by the feature quantity arrangement means ,
The feature amount of a particular rank is calculated as a reference feature amount in one in which more a reference image calculating means for the reference image only background specific region is captured with a reference feature amount calculated as described above.

An image processing apparatus according to a second aspect of the present invention is an image processing apparatus that estimates a reference image in which only a background and a stationary object are captured from an image sequence in which a stationary object or a moving object is captured in the background. An image storage unit capable of storing an image sequence in which a stationary object or a moving object appears on the background, and a feature amount extraction unit for calculating a feature amount of a specific area of each image in the image sequence stored in the image storage unit. , The probability distribution calculating means for obtaining the occurrence probability distribution of the feature amount calculated by the feature amount extracting means, and the order of the occurrence probability distribution of the specific region of each image obtained by the probability distribution calculating means, based on the image sequence. From the order in which the
From the probability distribution array means for rearranging to an order based on the magnitude of the probability value and a plurality of occurrence probability distributions rearranged in order by the probability distribution array means ,
Calculating a probability value of a specific order based probability distribution,
And a reference probability calculating means for calculating the reference occurrence probability distribution in the background in the specific region having the calculated reference occurrence probability distribution.

According to the present invention, it is difficult to distinguish and detect only a moving object because there is a change in luminance other than the object to be detected in the image, and the reference does not include the moving object (background).
If it is not possible to prepare a moving image in advance, or if it is difficult to detect a moving object with a fixed reference image due to a gradual change in the shooting environment, the reference image or background probability distribution is set to the moving object. By updating the information so that it is not included, it is possible to distinguish and detect only the moving object to be detected without previously capturing the background image.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment FIG. 1 is a schematic configuration diagram of a first embodiment which is an embodiment of the present invention. FIG. 4 shows a flowchart of the process of the moving object detecting method according to the first embodiment.

In this embodiment, an image storage means 11 capable of storing a plurality of images, a feature extraction means 12 for calculating a feature amount for each pixel or a region, and a plurality of feature amounts are arranged in a predetermined order. The feature arranging means 13 for rearranging and the moving object discriminating means 14 for discriminating the presence or absence of a moving object for each pixel or each area.

Further, in the case of producing a moving object detecting device capable of actually detecting a moving object, in addition to the above means, an image providing an image (image sequence) in the first embodiment of the present invention. It is provided with providing means 101 and result display means 102 for displaying the result of moving object detection to the user. The image providing means 101 may be a general TV camera or a video tape recorder.

(1) Image Storage Means 11 The image storage means 11 comprises a plurality (n number) of image memory groups M1, ...
From the video image sent from the No. 1, the image frames are sequentially arranged in the image memories M1, M2, ... At predetermined time intervals C.
Accumulates in ... If it is stored in the image memory Mn, the next frame is stored in M1 and is stored again in order (see steps a1 to a4 in FIG. 4).

(2) Characteristic amount extracting means 12 The characteristic amount extracting means 12 is composed of the image memories M1, ..., Mn in the image accumulating means 11 until one frame is accumulated and the next frame is accumulated. The feature amounts of n pixels corresponding to the same image coordinate position of are calculated for pixels of all coordinates.

For example, as shown in FIG. 2, the sizes of the images stored in each image memory Mi (i = 1, ..., N) are all the same w pixels × h pixels, and the image memories M1 ,.
Each feature amount v1 of n pixels (x, y) 1, ..., (x, y) n corresponding to the same image coordinate (x, y) in Mn
(X, y), ..., Vn (x, y) are calculated (see step a5 in FIG. 4).

Examples of the characteristic amount include the following.

If the input image is an RGB color image,

[Equation 1] If a linear sum such as
(X, y) is a gray level (luminance value) at the pixel (x, y).

Where r (x, y), g (x, y), b
(X, y) are RGB values of each color image.

Further, not only this but also element values such as hue H and saturation S in the Munsell color system can be used, and other generally known color systems XYZ, UCS, C.
MY, YIQ, Ostwald, L * u * v *, L * a *
It is possible to obtain an element value of a color system such as b * and use it as a feature amount as described above. For the conversion method between each color system, refer to Reference 5 “Takaki and Shimoda“ Image Analysis Handbook ”, University of Tokyo Press IS.
Details on "BN 4-13-061107-0 C3050".

Further, it is also possible to use the result of performing the differential operation or the integral operation spatially or temporally in the image memory Mi as a feature amount.

Specifically, as well as the well-known spatial differential calculation, Sobel, Roberts, Robinson, P
There are differential operators such as rewitt, Kirsch, and Canny, and Laplacian Gaussian and moment operators.
The edge strength as a result of applying these operators to the image of the image memory Mi is used as the feature amount v (x, y).

It is also possible to use the result of noise removal processing such as an integral averaging filter or median filter.

The above-mentioned operators and filters are also described in detail in Reference 5 mentioned above.

Further, in the above, the statistical amount that can be obtained for each pixel in a predetermined minute area in the image can also be used as the feature amount.

Examples of this statistic include average value, median value, mode value, range, variance, standard deviation, and average deviation. These statistics are calculated for the pixel of interest (x,
y) may be calculated in 8 neighborhoods (3 × 3 pixels), or (x,
y) and an arbitrary pixel centered on four sides may be used. Furthermore, the feature amount v (x, y) is used as the statistical amount obtained in a predetermined area of each (x, y). Is possible.

When a certain pixel (x, y) is selected, first, as described above, the feature amount extraction means 12 performs image memory M.
A feature amount is calculated for n pixels corresponding to the selected pixel (x, y) in 1, ..., Mn, and then n is calculated by a predetermined method in the feature arrangement means 13 as described below. The order of the individual feature amounts is rearranged, and the change determination unit 14 determines the presence or absence of a moving object for each pixel using the result. And this procedure is

[Equation 2] The moving object in the video is detected by the above.

(3) Feature Arrangement Unit 13 In the feature arrangement unit 13, as shown in FIG. 3, n feature quantities v1 (x, x, which are calculated by the feature extraction unit 12 for the selected pixel (x, y). y), ..., Vn (x, y) are sent, the feature amounts are rearranged in the order of the magnitude of the value of the feature amount by comparing the feature amounts, and the feature amount buffer v in the feature array means 13 is arranged. '1 (x, y), ..., v'n
Sequentially store in (x, y) (step a6 in FIG. 4)
reference).

The order of rearrangement at this time may be either descending or ascending, but in the future, it is assumed that the ascending order is rearranged. That is, the description will be continued on the assumption that the minimum value is stored in v′1 (x, y) and the maximum value is stored in v′n (x, y).

The feature arrangement means 13 outputs feature quantities v'k (x, y) and (k: rank) of a predetermined rank as reference values for detecting changes (step in FIG. 4). a7).

The means for rearranging the values in order and outputting the value of a predetermined rank is generally called a rank filter.

Like this rank filter, one feature quantity of a certain rank may be output as a reference value, but a value calculated by a certain formula from feature quantities arranged in ascending order may be output. It may be set to.

For example, when the median value is set to be output as the reference value,

[Equation 3] As described above, it depends on whether n is an odd number or an even number.

As described above, one form of the rank filter, which outputs the median value in particular, is called a median filter.

In addition, the following

[Equation 4] As described above, a calculation formula that is known to be optimal empirically may be used as a method of estimating the median value, and v′1 (x, y), … 、
It is possible to use a calculation formula for estimating the feature quantity v′k (x, y) of a certain rank by an arbitrary linear or non-linear combination of v′n (x, y).

What is important in the feature arrangement means 13 is that
v'k (x, y) is defined for n so that v'k (x, y) represents the feature amount of the pixel in the background scene.

Here, a case will be described in which the feature quantity array means 13 outputs one feature quantity of a specific rank as a reference value, that is, a rank filter.

The pixel (x, y) of interest in the image now
Is assumed to be passed by a moving object, and at the time of passing through this pixel, an image frame capture interval C (the image is accumulated in a certain image memory Mi and the next memory M (i + 1)
(Until the image is stored in)).

In this case, if a moving object is captured in a pixel (x, y) of interest in a certain memory Mi, the next image memory M {(i + 1) mod n} (mod n is n It is unknown whether or not the moving object is reflected in the pixel (x, y) of (dividing the remainder), but the moving object is detected in the pixel (x, y) of the next image memory M {(i + 2) mod n}. Has passed through the pixel and is not always visible. That is, at this time, it can be said that the moving object is captured only in at most two continuous image memories.

From the above, v′3 (x, y), ..., V ′ (n, which excludes at least two of the rearranged feature quantities of the feature array means 13 from at least the smaller one and the larger one, respectively.
-2) It can be seen that (x, y) represents the feature amount of that pixel in the background scene.

In this way, when the time required for a moving object to pass through a pixel is at most m times the image frame acquisition interval, the rearranged feature amount is from the smaller one to the larger one ( v ′ (m + 2) (x, y), ..., V ′ (n− (m +
1)) (x, y) represents the feature amount of the background scene.

From this, for example, when it is known that the feature amount of the moving object is smaller than that of the background, v '
If the feature amount of (m + 2) (x, y) or more is v ′ (n− (m +
1)) (x, y) or less, or the median of v ′ (x, y) when the feature of the moving object is unknown, the reference (background) feature v′k ( It is understood that it is sufficient to output as x, y).

(4) Change discriminating means 14 In the change discriminating means 14, the reference (background) characteristic amount v'k (x,
y) is compared with the feature amount v′i (x, y) of the pixel (x, y) of the image memory Mi for which the moving object detection process is desired to be performed to determine whether the moving object is in that pixel. I do.

As a method of discrimination, for example, the absolute value of the difference between the two is calculated, and when this is larger than a predetermined threshold value T, that is,

[Equation 5] When the condition is satisfied, it is determined that the pixel has a moving object (see steps a8 to a10 in FIG. 4).

In this way, as described above, all pixels in the image memory Mi are

[Equation 6] By performing the moving object detection process for, the moving object in the video is detected (see step a11 in FIG. 4).

The detection result of the moving object is displayed by the result display means 10
In addition to being displayed to the user by 2 (see step a12 in FIG. 4), an alarm that an intruder exists may be automatically issued.

Further, according to the procedure described above, the moving object detection process is performed in the specific image memory Mi among the images in the monitoring area while sequentially capturing the images in the monitoring areas into the image memories M1, ... The moving object detection can be continuously performed (step a in FIG. 4).
13).

Second Embodiment FIG. 5 is a schematic configuration diagram of the second embodiment of the present invention. Flowcharts of processing of the moving object detecting method according to the second embodiment are shown in FIGS.

In this embodiment, the image storage means 21 capable of storing a plurality of images, the feature extraction means 22 for calculating the feature amount for each pixel or each small area, and the spatiotemporal area of the pixel or small area are provided. Probability distribution calculating means 23 for obtaining the occurrence probability distribution of the feature quantity, probability distribution array means 24 for rearranging the order of the occurrence probabilities of the feature quantity by a predetermined method,
The moving object discriminating unit 25 discriminates the presence / absence of a moving object for each pixel or each small area using the rearranged result.

When a moving object detecting device capable of actually detecting a moving object is created, in addition to the above means, the same image as the first embodiment of the present invention can be obtained. And a result display unit 202 for displaying the result of moving object detection to the user.

In Reference Document 4, for disturbances that are erroneously detected as a moving object to be detected, such as fluctuations of trees and irregular reflection of sunlight on the water surface, which cause repeated image fluctuations in the monitoring area. However, a method has been proposed in which a disturbance and a moving object can be distinguished and detected by using a statistical discrimination method. In this method, it is necessary to calculate the occurrence probability distribution of the feature amount at each pixel from the background image that does not include the moving object in advance, and the background image cannot be prepared in advance, or the environmental conditions gradually change. This method could not be applied to the case where
The second embodiment of the present invention intends to cope with the above-mentioned inconvenience by realizing a method of updating the occurrence probability distribution of the background feature quantity as needed.

(1) Image Accumulating Means 21 The image accumulating means 21 is composed of a plurality (n number) of image memory groups M1, ..., Mn for accumulating images, as in the first embodiment. From the video sent from
Image frames sequentially accumulate images in the image memories M1, M2, ... For each predetermined time period C. If it is stored in the image memory Mn, the next frame is stored in M1 and is stored again in order (see steps b1 to b5 in FIG. 8).

(2) Feature Extracting Means 22 Like the first embodiment, the feature extracting means 22 determines the specified pixel (x, y) of the arbitrarily specified image memory Mi. Vi according to the method
Calculate (x, y). As the method of calculating the feature amount, any method described in the first embodiment may be used (see step b6 in FIG. 8).

(3) Probability distribution calculating means 23 When the images are stored in the image memory groups M1, ..., Mn of the image storing means 21, the feature extracting means 22 extracts all the pixels in all the image memories. Is calculated in the probability distribution calculation means 23 in exactly the same manner as the occurrence probability calculation processing of Reference 4, that is, by dividing the accumulation of the characteristic amount for each pixel by the cumulative frequency, the pixel as shown in FIG. The occurrence probability distribution p xy (v) for each feature amount v in (x, y) is obtained (step b in FIG. 8).
7).

Here, it is assumed that the pixel (i, j) and the region R xy in the first embodiment of Reference Document 4 are the same,
Let p xy (I) be read as p xy (v). In Reference Document 4, a probability distribution p xy (v) is obtained from a background image prepared in advance, and using this, the posterior probability w ′ (of the event that there is a change in the pixel (x, y) of the image frame i ( Whether or not the image has changed is determined by calculating x, y; i) and performing statistical determination. In the second embodiment of the present invention, the probability distribution p xy (v) of the feature quantity is calculated by the method described below without preparing a background image.
It is possible to obtain from a video including a moving object and update it at any time.

The occurrence probability distribution at pixel (x, y) obtained by the probability distribution calculating means 23 after the images are first stored in the image memories M1, ...
Let y1 (v). Here, the feature quantity vi (x, y) i:
It is assumed that 1, ..., N are set to take a value of a natural number from the minimum 1 to the maximum V, that is,

[Equation 7] Next, after the images are once stored in the image memories M1, ..., Mn, the occurrence probability distribution at the pixel (x, y) obtained by repeating the same procedure is set as p xy2 (v). In this way, it is assumed that the occurrence probability distribution p xyj (v) is obtained every time an image is stored in the image memory, and this is repeated J times. After this, that is, in the probability distribution calculating means 23, the occurrence probability distribution p xyj (v) (j = 1, 1) of the feature amount v in all the pixels (x, y).
, J) have been obtained J times (see steps b8 to b10 in FIG. 8).

(4) Probability distribution arranging means 24 In the probability distribution arranging means 24, as shown in FIG. 7, from the occurrence probability distribution p xyj (v) obtained J times, the distribution at each pixel (x, y) Pxy1 for each element v of
(V), ..., PxyJ (v) are rearranged in the same way as the feature arrangement means 13 in the first embodiment by the probability value size according to a predetermined method, and the probability value buffer p , p'xyJ (v) are stored in order (see step b12 in FIG. 8).

From this, as in the first embodiment,
A probability value of a predetermined rank is obtained and set as a probability value p′xyk (v) with the characteristic value v on the reference (background) (see step b12 in FIG. 8).

Reference value p'xyk (v) obtained here
Is, as described in the first embodiment, a rank filter, a median filter, or an arbitrary p xyj
An estimated value of a certain rank obtained by the combination of (v) can be used.

Here again, the important thing is p'xyk
That is, p′xyk (v) is determined for J so that (v) represents the probability value of the feature amount v of the pixel (x, y) in the background scene. This can be set exactly as in the first embodiment. That is, even if the moving object passes through the pixel (x, y), the image memory M1,
..., the same time as the image is accumulated in Mn C * n
Suppose it only takes. In this case, if the moving object is shown in the image memory group accumulated for the jth time, it is not known whether the moving object is shown in the image memory group accumulated for the next (j + 1) th time. However, a moving object has not passed through the image memory group stored in the (j + 2) th time because it is passing by.

When the intrusion of the object is not frequent and the number of times the background is imaged is greater than the number of times the moving object is imaged when focusing on a certain pixel, the rearranged probability values p '.
Probability values p′xy3 (v), ..., P′xy (J−2) obtained by removing two of the smaller and larger xyj (v).
It can be seen that (v) is obtained from the background scene.

Similarly, the time required for a moving object to pass through a pixel is at most m times the time C * n, which is the same as the time when all the images are stored in the image memories M1, ..., Mn. In some cases, the probability value p′xy obtained by removing (m + 1) from the smaller rearranged probability value and the larger rearranged probability value.
(M + 2) (v), ..., p'xy (J-m-1) (v)
Is required from the background scene.

Of these, probability value p'xyk of arbitrary rank is given.
The probability distribution array means 24 can output (v) as a probability value of the feature amount v at the reference (background) pixel (x, y).

The above procedure is performed for all feature values of all pixels (x, y).

[Equation 8] Is repeated (see steps b14 to b16 in FIG. 8).

Here, the total of v of the standard probability distribution p'xyk (v) output from the probability distribution arrangement means 24 needs to be 1 statistically.

That is, since it is necessary to satisfy the following equation,

[Equation 9] Probability distribution p ″ xyk (v) normalized by the following formula
May be recalculated and output as a probability distribution of the feature amount v at the pixel (x, y) (see step b17 in FIG. 8).

[0073]

[Equation 10] (5) Moving Object Discriminating Means 25 In this way, the occurrence probability distribution p′xyk of the feature quantity v in the background scene estimated by the probability distribution arranging means 24.
(V) or p ″ xyk (v) is obtained, and using this, in the moving object discriminating means 25, in the same manner as the first embodiment in Reference Document 4, the pixel (x, y) of the image memory Mi is obtained. ), The posterior probability w ′ (x, y; i) of the event that there is a change in (that is, the moving object is in the pixel) is calculated, and the statistical determination is performed using the same method as in the reference document 4, That is, the probability value of the presence / absence of an unsteady change is obtained from the occurrence probability distribution for each pixel, and the presence / absence of a moving object at that pixel (x, y) is determined (see steps b18 to b21 in FIG. 8).

When the discrimination is completed for all the pixels of a certain image memory Mi (see step b22 in FIG. 8), the result is displayed to the user by the result display means 202 (see step b23 in FIG. 9).
An alert that there is an intruder may be automatically issued.

In this way, the image is displayed in the image memory M1,
, Mn are sequentially stored, and if all the image memories perform the moving object determination once again, the image memory M is sequentially stored next.
Images are stored in 1, ..., Mn, and the occurrence probability distribution p′xyk (v) is estimated and calculated from a new image to be updated (step b in FIG. 9).
23 to b29), the moving object detection can be realized without preparing a background image in advance.

FIG. 10A shows a person crossing a road,
It is an original image of a shimmering tree after that person,
FIG. 10B is a result of processing the original image by a conventional moving object detection method (difference processing with the background image).
0 (c) is the result of moving object detection of the original image according to the second embodiment of the present invention.

Comparing the results of FIGS. 10B and 10C, in the conventional method, a fluctuating object other than the moving object is detected, but in the second embodiment only the moving person is detected. Has been detected.

[0078]

According to the image processing apparatus of the present invention, in the case of detecting a moving object in a video such as an image monitoring apparatus for finding an intruder using an image pickup apparatus such as a TV camera, When it is difficult to distinguish and detect only moving objects because there is a change in the brightness of the image other than the detection target, and it is not possible to prepare in advance a reference (background) image that does not include moving objects, or ,
Even when it is difficult to detect a moving object in a fixed reference image due to a gradual change in the shooting environment, the background image is updated in advance by updating the reference image or the background probability distribution so as not to include the moving object. It is possible to achieve a great practical effect such that only a moving object to be detected can be distinguished and detected without taking a photograph.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an image memory in the image storage means of the present invention.

FIG. 3 is an explanatory diagram of a reference feature amount output in the feature arrangement means of the present invention.

FIG. 4 is a flowchart of a moving object detection process in the first embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a probability distribution of feature quantities according to the second embodiment of this invention.

FIG. 7 is an explanatory diagram of reference probability value output in the probability distribution array means of the present invention.

FIG. 8 is a flowchart of a moving object detection process in the second embodiment of the present invention.

FIG. 9 is a continued flowchart of FIG.

10A is a diagram of an original image, FIG. 10B is a diagram of an image showing a result of moving object detection using a conventional method,
(C) is a diagram of an image showing a result of detecting a moving object using the second embodiment of the present invention.

[Explanation of symbols]

11 Image storage means 12 Feature extraction means 13 Feature Arrangement Means 14 Moving object discrimination means

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Claims (6)

(57) [Claims] 1. An image processing apparatus for estimating a reference image in which only a background and a stationary object are reflected from an image sequence in which a stationary object or a moving object is reflected in the background. An image storage unit capable of storing an image sequence showing an object, a feature amount extraction unit for calculating a feature amount of a specific region of each image in the image sequence stored in the image storage unit, and a calculation by the feature amount extraction unit The feature quantity arrangement means for arranging the order of the feature quantities of the specific regions of the respective images, which are arranged based on the image sequence, to the order based on the magnitude of the feature quantity, and the order of the feature quantity arrangement means From a plurality of sorted features , a specific rank of the sorted order
The image processing apparatus calculates the feature quantity as a reference feature amount, and wherein the more becomes possible as the reference image calculating means for the reference image only background specific region is captured with a reference feature amount calculated as described above. 2. A selecting means for selecting one image of which the presence or absence of a moving object is to be detected from the image sequence accumulated in the image accumulating means, and a selecting feature of the selected image selected by the selecting means. A selected feature amount extraction means for calculating an amount, and a selected feature amount calculated from the selected feature amount extraction means,
The image processing apparatus according to claim 1, further comprising a moving object determination unit that compares the reference feature amounts calculated by the reference image calculation unit and determines the presence or absence of a moving object in the selected image. . 3. An image processing apparatus for estimating a reference image in which only a background and a stationary object are reflected from an image sequence in which a stationary object or a moving object is reflected in the background, wherein the stationary object or the moving object is moved in the background. An image storage unit capable of storing an image sequence showing an object, a feature amount extraction unit for calculating a feature amount of a specific region of each image in the image sequence stored in the image storage unit, and a calculation by the feature amount extraction unit and the probability distribution calculating means for determining the probability distribution of the feature amount, the order of the occurrence probability distribution of the specific area of the image obtained by the probability distribution calculating means, of the order arranged on the basis of the image sequence, the occurrence a sort probability distribution sequence means to order based on the magnitude of the probability value of the probability distribution, a plurality of probability distributions sorted order by the probability distribution arrangement means, the sorted order Particular in the
Of calculating the corresponding probability distribution in the probability rank as a reference probability distribution, the more becomes possible as a reference probability calculating means for the reference probability distribution of the background in a particular region having a reference occurrence probability distribution calculated as described above A characteristic image processing device. 4. A selection means for selecting one image from which the presence or absence of a moving object is to be detected from the image sequence stored in the image storage means, and a selection feature of the selected image selected by the selection means. A selected feature amount extraction means for calculating an amount, and a selected feature amount calculated from the selected feature amount extraction means,
A moving object discriminating means for discriminating the presence or absence of a moving object in the selected image by calculating a probability value of the selected feature amount from the reference occurrence probability distribution calculated by the reference probability calculating means. The image processing device according to claim 3. 5. An image processing method for estimating a reference image showing only a background and a stationary object from an image sequence in which a stationary object or a moving object is reflected on the background, the method comprising: The feature amount of the specific area of each image in the image sequence in which the stationary object or the moving object is captured is calculated, and the order of the feature amount of the specific region of each calculated image is calculated based on the order of the image sequence. , rearranged to the order based on the feature amount of large and small <br/>, from a plurality of feature amounts that order is sorted, and the feature amount of a particular rank in the sorted order as reference feature amounts
The image processing method is characterized in that the specific region having the calculated reference feature amount is used as a reference image in which only the background is captured. 6. An image processing method for detecting a reference image including only a background and a stationary object from an image sequence in which a stationary object or a moving object is reflected on a background, the method comprising: Calculate the occurrence probability distribution of the specific area of each image in the image sequence in which a static object or a moving object is captured, and arrange the order of the occurrence probability distribution of the calculated specific region of each image based on the image sequence. From the order, the occurrence probability
Sort into an order based on the magnitude of the probability value of the rate distribution, and from a plurality of occurrence probability distributions in which this order is sorted , correspond to the probability value of a specific rank in the sorted order
The image processing method calculates the probability distribution as a reference probability distribution, characterized by a reference probability distribution of the background in a particular region having a reference occurrence probability distribution calculated as described above.