JP2008237625A - Degree of visibility judging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a degree of visibility judging apparatus capable of quantitatively evaluating the degree of visibility on "the range and extent of visibility of a person" concerning an object in his/her visual field. <P>SOLUTION: The degree of visibility judging apparatus includes: a photographing part 102 for photographing the image of the person; a photographing part 107 for photographing the in-visual field image of the person; a face detecting part 103 for detecting the facial area of the person, based on the image of the person; an visual line detecting part 104 for detecting the visual line direction of the person, based on the facial area; a degree of visibility distribution database 105 for storing degree of visibility distribution data expressing distribution of the degree of visibility of the object in the visual field; a degree of visibility distribution generating part 106 for generating the distribution of degree of visibility of the object in the visual field of the person in the in-visual field image through the use of the visual line direction of the person and the degree of visibility distribution data; and a degree of visibility judging part 111 for calculating the degree of visibility of the object, which is detected from the in-visual field image, through the use of the degree of visibility distribution. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a visibility determination apparatus that detects a person's line of sight and field of view using image processing and determines the degree of appearance in the person's field of view.

  As an apparatus using a conventional gaze detection technique, there is an apparatus that detects a gaze direction of a person photographed by a camera and determines what is an object ahead of the gaze direction (see Patent Document 1). FIG. 15 shows an apparatus for market research using the conventional gaze detection technique described in Patent Document 1. In FIG. 15, a product is placed on an arbitrary shelf 2 of the product display case 1, and a plurality of cameras 3-1 to. When the subject is looking at the product in front of the shelf, the subject is photographed by the installed cameras 3-1 to 3 -X, and the line-of-sight direction is detected from the face direction and the center position of the black eye. Then, the region of the shelf 2 is divided into a plurality of regions, and it is determined which region the line-of-sight direction is directed to. Further, whether or not the user has watched is determined based on whether or not the line of sight has remained in the area for a certain period of time.

  Another document proposes a method for evaluating the degree of attention to an information presentation such as an advertisement (see Patent Document 2). FIG. 16 shows an information collecting apparatus described in Patent Document 2. The person installed in front of the information presentation is photographed by a camera installed in front of the information presentation, and gaze information indicating that the person is staring at the information presentation is acquired, and the behavior pattern of the person The degree of attention to a person's information presentation is evaluated by using a combination with the information. For example, the degree of attention is weighted for each action such as whether the information is presented while passing, whether it is stopped, or approached, and the overall degree of attention is evaluated.

  Also, with regard to the gaze detection technology that serves as the base, some literature calculates the projected coordinates of the eyeball center and the coordinates of the iris center, and calculates the direction connecting the two points of the projected coordinates of the eyeball center and the iris center coordinates as the gaze direction. (See Patent Document 3). 17 and 18 are schematic views thereof.

In another document, a method is defined in which a triangle composed of three points of both eyes and nose is defined, and the gaze direction of the subject is determined from the regularity of the movement of the center of gravity of the triangle (see Patent Document 4). FIG. 19 shows a schematic diagram thereof.
Japanese Patent Laying-Open No. 2006-293786 (page 10-13, FIGS. 1-2) JP 2003-216938 A (page 3-8, FIGS. 1 to 3) JP 2006-285531 A (page 6-14, FIG. 4 to FIG. 7) Japanese Patent Laying-Open No. 2005-81101 (page 4-7, FIGS. 1 to 8)

  However, in the conventional configuration, only the direction of the line of sight is detected to determine the object to be viewed and the gaze determination is performed, and the gaze point is one point, which is “looking” or “not looking”. Only binary values were obtained. Also, the degree of attention has been determined by using the movement of the line of sight and the stagnation time.

  The gaze direction detection is effective if it is simply the determination of what is being watched, but when considering from the viewpoint of how people actually see things, the person is only looking at them. The surrounding information is also visible. It is known that objects look good in the direction of the line of sight, and relative visual acuity rapidly decreases in areas that are out of angle, but it is not completely invisible. It is said that the human field of view is about 120 to 160 degrees, and in that range, it can be said that some sort of thing can be seen to some extent.

  In the conventional gaze determination method based on the detection of the gaze direction, only the determination of what the person is gazing at is performed, so attention has been paid to what is ahead of the gaze direction. The view of the surroundings is not considered. That is, there is a problem in that because of a binary judgment criterion, nothing other than an object ahead of the line-of-sight direction is handled. However, when considering the use of human visual information, not only what the person is gazing at, but also what is in the vicinity of the person ’s line of sight, that is, what is in the field of view? This is considered to be very important.

  The present invention solves the above-mentioned conventional problem, and can visually evaluate the degree of visibility of what is in the human field of view, "how far and how much is visible" An object is to provide a determination device.

  In order to solve the above-described conventional problems, a visibility determination apparatus according to the present invention includes a person image capturing unit that captures a person image, an in-field image capturing unit that captures an in-person image of the person, and the person image capturing. A face detection unit that detects a person's face area based on the person image captured by the unit, a line-of-sight detection unit that detects a person's line-of-sight direction based on the face area detected by the face detection unit, and A visibility distribution database storing visibility distribution data representing the distribution of the visibility of an object, the gaze direction of the person detected by the gaze detection unit, and the visibility distribution database stored in the visibility distribution database. Using the visibility distribution data, a visibility distribution generation unit that generates a distribution of the visibility of objects in the field of view of the person in the in-view image, and the visibility distribution generation unit generates the appearance distribution Said person in view image A visibility determination unit that calculates the visibility of the object detected from the in-view image captured by the in-view image capturing unit using the distribution of the visibility of objects in the field of view. It is characterized by. According to this configuration, using the gaze direction of the person detected based on the person image photographed by the person image photographing unit and the visibility distribution data, the person in the view image captured by the in-field image photographing unit is detected. While generating the distribution of the visibility of an object in the field of view, the degree of visibility of the object can be calculated by detecting the object from the image in the field of view captured by the in-field image capturing unit. . As a result, it is possible to quantitatively evaluate the degree of visibility of “how far and how far” an object in the human field of view can be seen.

  In addition, the visibility determination device of the present invention is based on a video display unit that is a target for displaying video, a human image shooting unit that takes a human image, and the person image shot by the human image shooting unit. Based on the face detection unit that detects the face area of the person, the gaze detection unit that detects the gaze direction of the person based on the face area detected by the face detection unit, and the face area detected by the face detection unit A person position measuring unit that measures the positional relationship between the person image photographing means and the person, a visibility distribution database that stores visibility distribution data representing the distribution of the visibility of objects in the field of view, The gaze direction of the person detected by the gaze detection unit, the positional relationship between the person image photographing means and the person measured by the person position measurement unit, and the visibility distribution data stored in the visibility distribution database The person using A visibility distribution generation unit that generates a distribution of the visibility of an object in the field of view of the object, a distribution of the visibility of an object in the field of view of the person generated by the visibility distribution generation unit, and A degree-of-view determination unit that calculates the degree of appearance of the image display unit that is a target using information about the size of the image display unit or the positional relationship between the image display unit and the person image capturing unit; It is characterized by that. According to this configuration, the gaze direction of the person detected based on the person image photographed by the person image photographing unit, the positional relationship between the person image photographing means and the person measured by the person position measuring unit, and the visibility distribution data are obtained. To generate a distribution of the visibility of an object in a person's field of view, and to calculate the visibility of the video display unit using the distribution of the visibility of an object in the field of view of the generated person Can do. Thereby, it is possible to quantitatively evaluate the degree of visibility of how far a person can see the video display unit.

  As described above, according to the visibility determination device of the present invention, not only “what is being watched” by a person but also “how much is seen to what extent” of an object in the field of view of a person. Can be quantitatively evaluated.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(Embodiment 1)
In the first embodiment, a mode in which the visibility determination device of the present invention is used as a driving support device will be described. This driving support apparatus quantitatively evaluates the degree of how the driver sees “how far and how much” and provides information to assist the driver in driving. First, the configuration of the driving support apparatus is shown in FIG. Reference numeral 102 denotes a human image capturing camera that captures a human image including the driver's face in order to detect the driver's head posture direction and line-of-sight direction. Reference numeral 103 denotes a face detection unit that detects a driver's face area based on a person image taken by the person image photographing camera 102. Reference numeral 104 denotes a head posture and line-of-sight detection unit that detects the driver's head posture direction and line-of-sight direction based on the face area detected by the face detection unit 103. A visibility distribution database 105 stores data representing the distribution of the visibility of objects in the field of view (hereinafter referred to as visibility distribution data). Details of the visibility and the distribution of the visibility will be described later. An in-field image capturing camera 107 shoots using the head posture direction and line-of-sight direction detected by the head posture and line-of-sight detection unit 104 and the visibility distribution data stored in the visibility distribution database 105. It is a visibility distribution generation part which produces | generates distribution of the visibility of the thing in a driver | operator's visual field in the visual field image to do.

  Reference numeral 107 denotes an in-field image capturing camera that captures an image corresponding to the driver's view (hereinafter referred to as an in-view image). Here, by using the head posture direction and the line-of-sight direction detected by the head posture and line-of-sight detection unit 104, it is possible to calculate to which part of the image captured by the in-field image capturing camera 107 the driver is visible. Therefore, the positional relationship among the person image capturing camera 102, the in-view image capturing camera 107, and the driver is preset and known. Reference numeral 109 denotes an object feature database that stores information indicating characteristics of an object whose visibility is to be determined (hereinafter referred to as an object). An object detection unit 110 detects an object similar to the object stored in the object feature database 109 and a position and an area in the image within the field of view from the image within the field of view captured by the image capturing camera 107 within the field of view. Reference numeral 111 denotes the visibility of the object detected by the object detection unit 110 using the distribution of the visibility of the object in the driver's field of view in the image within the field of view generated by the visibility distribution generation unit 106. This is a visibility determination unit.

  A visibility data storage unit 112 stores a history of the visibility of the object calculated by the visibility determination unit 111. A time series weight database 113 stores time series weight information set in advance in consideration of temporal changes. 114 is stored in the time series weight database 113 for the current object appearance calculated by the appearance determination unit 111 and the past appearance of the same object stored in the appearance data storage unit 112. It is a time-series appearance score calculation unit that calculates and evaluates a score of visibility taking into account temporal changes by weighting with time-series weight information (hereinafter referred to as a time-series visibility score).

  Reference numeral 115 denotes an object attribute database that stores information (hereinafter referred to as attribute information) such as the content related to the object detected by the object detection unit 110 and the importance of notification to the driver. Reference numeral 116 denotes an attribute information determination unit that acquires attribute information corresponding to the object detected by the object detection unit 110 from the object attribute database 115. 117 is a guidance information database that stores a target object evaluation score and guidance information that are used as a criterion for judging whether to provide information such as presence / absence of guidance to the driver, which is determined by the guidance information determination unit 118. 118 is stored in the guidance information database 117 using the attribute information of the object acquired by the attribute information determination unit 116 and the time-series appearance score of the object calculated by the time-series appearance score calculation unit 114. It is a guidance information provision judgment part which judges provision of guidance information, such as the presence or absence of guidance notice to a driver, and the contents of notice, based on a subject evaluation score. Reference numeral 119 denotes a guidance information display unit that provides guidance information to the driver in accordance with the presence or absence of the guidance notification determined by the guidance information determination unit 118 and the content of notification.

  Before describing the flow of a series of processes, the visibility and the visibility distribution will be described. It has been experimentally known that visual acuity decreases greatly once at the line of sight, and then decreases gradually. For example, the visual acuity with respect to the direction shifted by 2 degrees with respect to the line-of-sight direction is reduced to about 40%, about 10% when shifted 5 degrees, and about 5% when shifted 10 degrees. Visual acuity is the ability to visually distinguish between two points, and lowering visual acuity means that objects can be seen blurry with such a rough resolution. From this, the visibility is expressed by the degree of visibility of an object in the field of view based on the visual acuity at the center in the visual line direction and the visual acuity around the visual line direction (outside the center). It is also appropriate to define the visibility distribution as a function correlated with visual acuity, or a function having a visibility peak at the center of the line-of-sight direction. In this embodiment, as an example, the peak value of visual acuity is normalized to 1 based on the experimentally obtained visual acuity and the peripheral (out-of-center) visual acuity, and a normal distribution is applied thereto. The visibility distribution is defined. When the horizontal axis is the angle from the center of the line of sight and the vertical axis is the visibility, a normal distribution function that minimizes the square error with the visibility obtained experimentally using the least square method The visibility distribution function is derived and defined as a visibility distribution function, and the visibility distribution data obtained by converting this into data is stored in the visibility distribution database. An outline of the definition of the visibility distribution is shown in FIG. The normal distribution is used because it has a peak at the center similar to changes in visual acuity and tends to be expressed with a tendency to decrease before and after that. However, if the function has the same tendency, it is not limited to the normal distribution and Cauchy. Distributions and other functions defined uniquely may be used. In Embodiment 1, a value obtained by normalizing visual acuity is used as the visibility, but the present invention is not limited to this. For example, by using the value obtained by normalizing the square root of the visual acuity as the visibility, the change in the visibility can be gently expressed according to the change in the angle from the center of the line-of-sight direction.

  A flow of a series of processes of the driving support device configured as described above will be described. FIG. 2 is a flowchart showing processing operations performed by the driving support device. First, a person image including the driver's face is photographed by the person image photographing camera 102 (S201). The photographed person image is sent to the face detection unit 103, and the face detection unit 103 detects the driver's face area (S202). The driver's face area detected by the face detection unit 103 is sent to the head posture and gaze detection unit 104, and the head posture and gaze detection unit 104 detects the driver's head posture direction and gaze direction ( S203). Here, for the detection of the face area, for example, a standard gray pattern or frequency component of a face learned in advance is prepared, and a pattern matching method for detecting an area similar to this pattern from the image as a face area is used. Can be mentioned. The head posture direction is detected by detecting representative points of the face such as eyes, nose, mouth, etc., and detecting the posture direction from the positional relationship, as in Active Appearance Models using 3D models. For example, there is a method for obtaining the posture direction of the entire head by changing the shape and texture of the entire face so as to match the input face image. Further, the gaze direction can be detected by the methods as described in Patent Documents 3 and 4 described in the background section. These are all listed as examples of the detection method, and are not particularly limited to this, and any method may be used.

  The driver's head posture direction and line-of-sight direction detected by the head posture and line-of-sight detection unit 104 are sent to the visibility distribution generation unit 106, and the visibility distribution generation unit 106 captures the in-field image capturing camera 107. The distribution of the visibility of the objects in the driver's field of view in the field-of-view image (the visibility distribution map) is generated (S204). The visibility distribution generation unit 106 first calculates the position (point) that the driver is looking in the in-view image captured by the in-view image capturing camera 107. As described above, the positional relationship among the person image capturing camera 102, the in-field image capturing camera 107, and the driver is preset and known. Therefore, by using the head posture direction and line-of-sight direction of the driver detected by the head posture and line-of-sight detection unit 104 and the angle-of-view information of the in-field image capturing camera 107, the image is captured by the in-field image capturing camera 107. It is possible to calculate the position (point) that the driver is viewing in the in-view image. An example is shown in FIG. FIG. 4 is a schematic view of the driver and the in-view image capturing camera 107 viewed from above. In this example, the driver is directly behind the in-view image capturing camera 107. The angle of view of the in-field image capturing camera 107 is θ, the assumed shooting distance is m, and the distance between the in-view image capturing camera 107 and the driver is n. A plane at a shooting distance m at an angle of view θ is defined as a shooting plane for the in-view image. When the driver has a line of sight of α degrees in the horizontal direction, the difference in position on the photographing surface between the line-of-sight direction calculated from the position of the driver and the line-of-sight direction calculated from the in-field image photographing camera 107 is n × tan α. . Since the length of the photographing surface is 2 × m × tan (θ / 2), if the image size of the length of the photographing surface is D pixels and the image size of the position difference on the photographing surface is x pixels, The shift x pixel at is obtained by multiplying the image size D pixel, which is the resolution of the in-view image, by (positional difference on the photographing surface) / (length of the photographing surface). Thus, even when the position of the driver and the in-view image capturing camera 107 are different, the position (point) at which the driver is looking in the in-view image captured by the in-view image capturing camera 107 can be calculated. Although an example of calculation in the horizontal direction (horizontal direction) is shown here, the vertical direction (vertical direction) can be calculated in the same manner, and the visibility distribution generation unit 106 combines the calculation in the horizontal direction and the vertical direction. Thus, the position (point) of the field-of-view image viewed by the driver can be calculated three-dimensionally.

  Thereafter, the visibility distribution generation unit 106 sets the position (point) in the line-of-sight direction as the center of the line of sight, that is, the visual angle 0 degree, and the driver's image in the field-of-view image corresponding to the angle (shift angle) shifted from the line-of-sight center. A visibility distribution of an object in the field of view is calculated. An example of the calculation of the deviation angle is shown in FIG. When the shooting distance is m and the viewing angle of the driver is α, the shift angle β corresponding to the shift x from the center of the line of sight is β = α−arctan {(m × tan α−x) / m} as shown in the figure. Desired. When the deviation angle is calculated, the visibility distribution corresponding to the deviation angle is calculated using the visibility distribution data in the visibility distribution database 105. An example of a visibility distribution map of an object in the driver's field of view in the field of view image is shown in FIG. The distribution of visibility is expressed in shades. The darker the color, the higher the visibility, and the darkest position is the position (point) in the line-of-sight direction, that is, the center of the line of sight (viewing angle 0 degree). The spread of the distribution varies depending on the angle of view. That is, when the image is taken with a camera with a wide angle of view (6-a), the spread of the distribution becomes larger because the viewing angle is larger than when the image with a narrow angle of view is taken (6-b). In addition, although an example of calculation in the horizontal direction (horizontal direction) is shown here, the vertical direction (vertical direction) can be calculated in the same manner, and the visibility distribution generation unit 106 combines the calculation in the horizontal direction and the vertical direction. Thus, the visibility distribution of the object in the driver's field of view in the field-of-view image captured by the field-of-view image capturing camera 107 can be calculated three-dimensionally.

  On the other hand, an in-view image of the driver is captured by the in-view image capturing camera 107 (S205). The captured in-view image is sent to the object detection unit 110, and the object detection unit 110 detects an object similar to the object stored in the object feature database 109 from the in-view image and its position and area. (S206). The target object can assist driving by notifying the driver, such as a person, a road sign, a forward vehicle, or an oncoming vehicle. The object detection method may be a pattern matching method as described in S202.

  Further, attribute information related to the object detected by the object detection unit 110 by the attribute information determination unit 116 is acquired from the object attribute database 115 (S210). The attribute information represents the content of the target object, the importance of notification to the driver, or classification information, and is used to determine whether or not to finally notify the driver about the target object. An example of attribute information is shown in FIG.

また、対象物の領域Ｒの面積をＳとしたとき、平均値は、式２により表され、対象物の領域Ｒ内のｖ（ｘ）の平均を見え方度とする。

最大値は、式３により表され、対象物の領域Ｒ内のｖ（ｘ）の最大値を見え方度とし、最小値は、式４により表され、対象物の領域Ｒ内のｖ（ｘ）の最小値を見え方度とする。

さらに、メジアン値は、式５により表される。対象物の領域Ｒ内のｖ（ｘ）の集合＝（ｖ₁，ｖ₂，・・・ｖ_n）を大きさ順に並べ替えたときに中央に位置する値を見え方度とし、領域Ｒ内のｖ（ｘ）が偶数ある場合は、中央に近い２値の平均を見え方度とする。

本実施の形態１では積分値を対象物の見え方度とする。例を図８に示す。図中での見え方度分布は色の濃さで表現しており、色が濃いほど見え方度が高いことを表す。８−ａのような見え方度分布の中に人物が複数いた場合、見え方度分布を人物領域で積分して各人に対する見え方度を算出する。対象物の領域で積分する理由としては、視界内で占める面積が大きい方が目に付きやすい、すなわち広範囲に渡る見え方度を集めると考えられるためである。例えば８−ｂのように人物が視界内画像撮影カメラ１０７の近くに寄った場合、相対的に人物の領域は大きくなり、結果として見え方度の積分値も大きくなる。見え方度判定部１１１によって算出された対象物の見え方度は見え方度データ格納部１１２に保存される（Ｓ２０８）。 On the other hand, by the visibility determination unit 111, the position and area of the object in the in-view image detected by the object detection unit 110 and the driver's view in the in-view image generated by the visibility distribution generation unit 106. The visibility of the object is calculated from the distribution of the visibility of a certain object (S207). In the first embodiment, the visibility of an object is calculated by the distribution of the visibility of an object in the driver's field of view in the image within the field of view generated by the visibility distribution generation unit 106, and the object. Using the position and area of the object detected by the detection unit 110, the integrated value, average value, maximum value, minimum value, median value, or the like calculated based on them is used as the visibility of the object. That is, when the visibility at the coordinate x is v (x) and the region of the object is R, the integral value is expressed by Equation 1, and the sum of v (x) in the region R of the object is viewed. Degree.

Further, when the area of the region R of the object is S, the average value is expressed by Equation 2, and the average of v (x) in the region R of the object is the visibility.

The maximum value is represented by Expression 3, and the maximum value of v (x) in the region R of the object is defined as the visibility, and the minimum value is represented by Expression 4 and v (x in the region R of the object. ) Is the visibility.

Further, the median value is expressed by Equation 5. When the set of v (x) in the region R of the object = (v ₁ , v ₂ ,... V _n ) is rearranged in order of size, the value located in the center is taken as the visibility and When v (x) is even, the average of two values close to the center is set as the visibility.

In the first embodiment, the integral value is used as the visibility of the object. An example is shown in FIG. The visibility distribution in the figure is expressed by the color intensity, and the darker the color, the higher the visibility. When there are a plurality of persons in the visibility distribution such as 8-a, the visibility for each person is calculated by integrating the visibility distribution in the person region. The reason for integrating in the region of the object is that the larger the area occupied in the field of view, the easier it is to see, that is, it is considered that the visibility over a wide range is collected. For example, when the person is close to the in-view image capturing camera 107 as in 8-b, the area of the person is relatively large, and as a result, the integrated value of the visibility is also large. The visibility of the object calculated by the visibility determination unit 111 is stored in the visibility data storage unit 112 (S208).

  Then, after the current visibility of the object is calculated, the time-series appearance score calculation unit 114 calculates a time-series appearance score that takes into account temporal changes (S209). During driving, both the driver's line of sight and the object always move, so the visibility is constantly changing. Therefore, evaluation based on a wider range of information can be performed by considering the temporal change in visibility. Although there is a method of handling time series data by combining feature quantities in a time series and treating them as one feature quantity, in the first embodiment, the past visibility is given a monotonically decreasing weight, and the target The weighted sum of the visibility for a certain period in the past is set as the time series visibility score for each object. By assigning a monotonically decreasing weight over time, it is possible to perform evaluation with the highest importance on the current visibility while considering the past visibility.

  Thereafter, the guidance information provision determination unit 118 calculates the time-series appearance score of the object calculated by the time-series appearance score calculation unit 114 (S209), and the attribute information (S210) acquired by the attribute information determination unit 116. Is used to calculate an object evaluation score as a reference for determining provision of information to the final driver, and based on the object evaluation score stored in the guidance information database 117, whether or not there is a guidance notification to the driver And providing guidance information such as notification content is determined (S211). A calculation example of the object evaluation score is shown in FIG. In this example, the object evaluation score is set to be higher as the importance of the object is higher or the visibility of the object is lower, and the object is important, and is difficult to see for the driver. Will focus on the objects in This is an example, and the calculation method of the object evaluation score may be calculated using an expression other than this. For example, the importance and the visibility of an object are used as feature quantities, and an object evaluation score corresponding to the feature quantity is set in advance to create a statistical model that statistically learns the relationship between the feature quantity and the object evaluation score. A method of statistically calculating the object evaluation score of each object using this model is also conceivable.

  An example of guidance information stored in the guidance information database 117 is shown in FIG. For example, when the target is a pedestrian, the voice guidance and position guidance are issued while the target evaluation score is small to some extent, but the driver is not in the direction of the driver's line of sight. To guide the position. In the case of a restriction sign such as a speed limit, when the object evaluation score becomes larger than a certain fixed value, the sign contents are guided by voice. In the case of an auxiliary sign indicating the application time or section of the sign, it may be impossible to read if the visibility is lowered to some extent due to the character sign. Therefore, when the degree of visibility becomes low, that is, when the object evaluation score has increased to some extent, voice guidance of the contents is performed. Further, since the auxiliary sign is supplementary information for the sign at the top, the content of the sign at the top is also guided.

  Finally, when it is determined that the guidance information is provided by the guidance information determination unit 118, guidance information corresponding to the object evaluation score is provided to the driver through the guidance information display unit 119 (S212).

  As described above, according to the embodiment in which the visibility determination device according to the first embodiment is used as the driving support device, the visibility of “how far and how far” an object in the driver's field of view is quantified. The information that assists driving can be provided to the driver by determining the provision of the guidance information to the driver by using it in combination with the importance of the detected object.

(Embodiment 2)
In the second embodiment, a mode in which the visibility determination device of the present invention is used as a video display device will be described. This video display device quantitatively evaluates the degree of how the user sees "how far and how much" and reduces processing such as image adjustment in the area of the video display unit outside the user's field of view Is. First, the configuration of the video display device is shown in FIG. Reference numeral 1102 denotes a video display unit that displays a video. Reference numeral 1103 denotes a human image capturing camera that captures a human image including the user's face in order to detect the user's head posture direction and line-of-sight direction. Reference numeral 1104 denotes a face detection unit that detects a user's face area based on a person image captured by the person image capturing camera 1103. Reference numeral 1105 denotes a head posture / line-of-sight detection unit that detects the user's head posture direction and line-of-sight direction based on the user's face area detected by the face detection unit 1104. Reference numeral 1106 denotes a person position measuring unit that measures the positional relationship between the human image capturing camera 1103 and the user based on the face area of the user detected by the face detecting unit 1104. A visibility distribution database 1107 stores data representing the distribution of the visibility of objects in the field of view (hereinafter referred to as visibility distribution data). The details of the visibility and the distribution of the visibility are the same as those in the first embodiment, and will be omitted. Reference numeral 1108 denotes a video display unit information database that stores information on the size of the video display unit 1102 and the positional relationship between the video display unit 1102 and the person image capturing camera 1103. Reference numeral 1109 denotes a user's head posture direction and line-of-sight direction detected by the head posture and line-of-sight detection unit 1105, a positional relationship between the human image capturing camera 1103 measured by the person position measurement unit 1106 and the user, and a visibility distribution database 1107. Is a visibility distribution generation unit that generates a distribution of the visibility of objects in the user's field of view using the visibility distribution data stored in. Reference numeral 1110 denotes a distribution of the visibility of an object in the user's field of view generated by the visibility distribution generation unit 1109, the size of the video display unit 1102 stored in the video display unit information database 1108, and the video display unit 1102 and the person image. This is a video display unit visibility determination unit that calculates the degree of visibility of the video display unit 1102 of the user using information related to the positional relationship with the photographing camera 1103 and the like.

  Reference numeral 1111 denotes a video display unit visibility data storage unit that stores a visual history of the video display unit 1102 calculated by the video display unit visibility determination unit 1110. Reference numeral 1112 denotes a time series weight database storing time series weight information set in advance in consideration of temporal changes. Reference numeral 1113 denotes the current visibility of the video display unit 1102 calculated by the video display unit visibility determination unit 1110 and the past visibility of the video display unit 1102 stored in the video display unit visibility data storage unit 1111. The time series appearance degree score calculating unit calculates and evaluates the time series appearance degree score by weighting with the time series weight information stored in the time series weight database 1112.

  Reference numeral 1114 denotes a video information database storing video information to be displayed on the video display unit 1102. A display control unit 1115 performs processing such as image adjustment on the video displayed on the video display unit 1102 based on the time series visibility score of the video display unit 1102 calculated by the time series visibility score calculation unit 1113. is there.

  A flow of a series of processes of the video display device configured as described above will be described. FIG. 12 is a flowchart showing processing operations performed by the video display device. Since the processing from the human image acquisition in S1201 to the head posture direction and line-of-sight direction detection in S1203 is the same as that in the first embodiment, a description thereof will be omitted. The head posture and line-of-sight detection unit 1105 detects the user's head posture direction and line-of-sight direction based on the user's face area, while the person position measuring unit 1106 detects the person image capturing camera 1103 based on the user's face area. The positional relationship with the user is measured (S1204). The measurement of the positional relationship between the person image capturing camera 1103 and the user is not particularly limited, and an existing technique may be used. For example, by using the stereo method, a user is photographed simultaneously by stereo viewing using a plurality of cameras, and the three-dimensional position information of the user is obtained from the difference in position (parallax) reflected in each image using the principle of triangulation. Alternatively, the correlation between the size and position of the person's face reflected on the camera and the distance from the camera is learned in advance, and the positional relationship between the person image capturing camera 1103 and the user based on this learning model. A method for measuring the above can be considered.

  The user's head posture direction and line-of-sight direction detected by the head posture and line-of-sight detection unit 1105, and the positional relationship between the human image photographing camera 1103 measured by the person position measurement unit 1106 and the user are the visibility distribution generation unit 1109. The viewing angle distribution generation unit 1109 calculates the angle (deviation angle) deviated from the center of the line of sight with the position (line) in the line of sight as the center of the line of sight, that is, the viewing angle of 0 degrees. Note that the calculation example of the deviation angle is the same as that in the first embodiment, and is omitted. When the deviation angle is calculated, the visibility distribution corresponding to the deviation angle is calculated using the visibility distribution data in the visibility distribution database 1107. FIG. 13 shows an example of a visibility distribution map of an object in the user's field of view.

  Subsequently, the visibility of the video display unit 1102 is calculated by the video display unit visibility determination unit 1110 using the user's visibility distribution map generated by the visibility distribution generation unit 1109 (S1206). The degree of visibility of the video display unit 1102 is calculated using information on the size of the video display unit 1102 and the positional relationship between the video display unit 1102 and the person image capturing camera 1103 stored in the video display unit information database 1108. The user's visibility distribution on the display surface of the video display unit 1102 is calculated as the user's visibility of the video display unit 1102 (video display unit visibility). Note that the calculation of the visibility of the video display unit is the same as in the first embodiment, and is omitted. FIG. 14 shows the display surface of the video display unit 1102 and the visibility distribution of the user. Thereafter, the video display unit visibility calculated by the video display unit visibility determination unit 1110 is stored in the video display unit visibility data storage unit 1111 (S1207).

  Then, after the current video display portion visibility is calculated, the time-series visibility score calculation unit 1113 calculates a time-series visibility score in consideration of temporal changes (S1208). Note that the time series visibility score and its calculation are the same as in the first embodiment, and are therefore omitted. Thereafter, the display control unit 1115 performs processing such as image adjustment on the video displayed on the video display unit 1102 based on the time-series visibility score of the video display unit 1102 calculated by the time series visibility score calculation unit 1113. Is performed (S1209), and an image is displayed on the image display unit 1102 (S1210). The region where the time series visibility score is higher is the region that the user is currently viewing, and conversely, the region that is lower is less visible to the user. For this reason, even if the resolution is slightly reduced for an invisible area, for example, the relative visual acuity with respect to that area is originally low and it can only be seen vaguely. In this way, it is possible to reduce the amount of calculation in the video display device by reducing processing such as image adjustment for areas that are difficult for the user to notice. In the image adjustment process, in addition to reducing the resolution, it is conceivable to reduce brightness and contrast, and to reduce the refresh rate. As an advantage of reducing the amount of calculation in the video display device, it is possible to reduce the cost because it operates even with a device having a low absolute performance, and it is also possible to save energy because the amount of electricity used is also reduced.

  As described above, according to the mode of using the visibility determination device of the second embodiment as a video display device, it is possible to quantitatively evaluate the visibility of how much the user sees how far, By reducing processing such as image adjustment in the area of the video display unit outside the user's field of view, cost reduction and energy saving can be achieved by reducing the amount of computation in the video display device.

  As described above, according to the present invention, the degree of appearance of an object in the human field of view can be expressed as a numerical value. According to the present invention, unlike the binary determination of “seen” or “not seen” performed in the gaze determination based on the conventional gaze direction detection, the object around the gaze direction of the person, that is, in the field of view is “ It is possible to quantitatively evaluate the degree of visibility of “how far and how far it is visible”, and to perform more detailed determination and control based on the degree of visibility. Note that the present invention is not limited to the range described in the first or second embodiment, and can be appropriately changed and implemented as long as it does not depart from the gist of the present invention. That is, all forms other than the form in which determination and control are automatically performed according to the visibility of the object as in the first or second embodiment are possible. For example, a means of quantitatively evaluating easy-to-see areas that are easy to see by taking a change in the user's visibility distribution for the layout of stores, indoors, etc. It can also be used as an evaluation method for cognitive experiments.

The block diagram which shows the internal structure of the driving assistance apparatus in Embodiment 1 of this invention. The flowchart which shows the processing operation performed in Embodiment 1 of this invention. Figure showing a calculation example of the visibility distribution The figure which shows the calculation method of a driver | operator's gaze direction in the image in a visual field The figure which shows the calculation method of the deviation angle from a driver | operator's gaze direction in the image in a visual field The figure which shows the example of the visibility distribution of the in-view image Example of attributes stored in the target attribute database Diagram showing an example of the difference in the visibility of an object Example of calculating the object evaluation score Examples of judgment criteria and provided information stored in the guide information database 117 The block diagram which shows the internal structure of the image display apparatus in Embodiment 2 of this invention. The flowchart which shows the processing operation performed in Embodiment 2 of this invention. The figure which shows the example of spatial visibility distribution map The figure which shows the example of arrangement | positioning of the video display part in a spatial visibility distribution map The figure which shows the example of prior literature 1 The figure which shows the example of prior literature 2 The figure which shows the processing flow of the prior literature 3. The figure which shows the gaze direction calculation method of the prior literature 3. The figure which shows the gaze direction calculation method of the prior literature 4.

Explanation of symbols

102 Human Image Camera 103 Face Detection Unit 104 Head Posture and Line of Sight Detection Unit 105 Visibility Distribution Database 106 Visibility Distribution Generation Unit 107 In-Field Image Camera 109 Target Feature Database 110 Object Detection Unit 111 Visibility Determination Unit 112 visibility data storage unit 113 time series weight database 114 time series visibility score calculation unit 115 object attribute database 116 attribute information determination unit 117 guidance information database 118 guidance information determination unit 119 guidance information display unit 1102 video display unit 1103 Human image photographing camera 1104 Face detection unit 1105 Head posture and line-of-sight detection unit 1106 Human position measurement unit 1107 Appearance distribution database 1108 Video display unit information database 1109 Appearance distribution generation unit 1110 Appearance Determining unit 1111 appearance of temporary data storage unit 1112 time series weighting database 1113 series appeared Katado score calculating unit 1114 video database 1115 display control unit

Claims (8)

A person image shooting unit for shooting a person image;
An in-field image capturing unit for capturing an in-field image of a person;
A face detection unit that detects a face area of a person based on the person image captured by the person image capturing unit;
A gaze detection unit that detects a gaze direction of a person based on the face area detected by the face detection unit;
A visibility distribution database storing visibility distribution data representing the distribution of the visibility of objects in the field of view;
Using the gaze direction of the person detected by the gaze detection unit and the visibility distribution data stored in the visibility distribution database, the visibility of an object in the view of the person in the in-view image A visibility distribution generation unit for generating a distribution of
Objects to be detected from the in-view image captured by the in-view image capturing unit using the distribution of the visibility of objects in the view of the person in the in-view image generated by the visibility distribution generation unit An appearance degree determining apparatus comprising: an appearance degree determining unit that calculates an appearance degree of an object. A visibility data storage unit that stores a history of the visibility of the object calculated by the visibility determination unit;
The current visibility of the target object calculated by the visibility determination unit and the past visibility of the same target object stored in the visibility data storage unit are set in consideration of temporal changes. The visibility according to claim 1, further comprising: a time-series appearance degree score calculation unit that calculates a score of appearance degree in consideration of temporal changes by weighting with time-series weight information. Judgment device. An attribute information determination unit for acquiring attribute information related to the object;
A guidance information provision determination unit that calculates an object evaluation score using the attribute information and the time-series appearance degree score, and determines provision of guidance information of the object based on the object evaluation score; The visibility determination apparatus according to claim 2, wherein: A video display unit as a target for displaying video;
A person image shooting unit for shooting a person image;
A face detection unit that detects a face area of a person based on the person image captured by the person image capturing unit;
A gaze detection unit that detects a gaze direction of a person based on the face area detected by the face detection unit;
A person position measuring unit that measures a positional relationship between the person image photographing unit and the person based on the face area detected by the face detecting unit;
A visibility distribution database storing visibility distribution data representing the distribution of the visibility of objects in the field of view;
The gaze direction of the person detected by the gaze detection unit, the positional relationship between the person image photographing means and the person measured by the person position measurement unit, and the visibility distribution data stored in the visibility distribution database A visibility distribution generation unit that generates a distribution of the visibility of objects in the field of view of the person,
Information relating to the distribution of the visibility of an object within the field of view of the person generated by the visibility distribution generation unit, and the size of the video display unit or the positional relationship between the video display unit and the human image photographing unit And a visibility determination unit that calculates a visibility of the video display unit that is an object. A visibility data storage unit that stores a history of visibility of the video display unit calculated by the visibility determination unit;
The current visibility of the video display unit calculated by the visibility determination unit and the past visibility of the video display unit stored in the visibility data storage unit are set in consideration of temporal changes. The visibility determination apparatus according to claim 4, further comprising a time-series appearance degree score calculation unit that calculates a time-series appearance degree score by weighting with the time-series weight information.   The display control unit for performing an image adjustment process on a video displayed on the video display unit based on the time-series visibility score calculated by the time-series visibility score calculation unit. 5. The visibility determination device according to 5.   In the visibility distribution data stored in the visibility distribution database, the visibility represents the degree of appearance of an object in the field of view based on the center of the line-of-sight direction and the visual acuity outside the center. 5. The visibility determination apparatus according to claim 1, wherein the orientation distribution is correlated with the visual acuity and expressed based on a function having a peak of the visibility in the center of the line-of-sight direction.   The visibility determination unit uses the visibility distribution and the position and region of the object, and calculates an integral value, an average value, a maximum value, a minimum value, or a median value calculated based on these distributions. The visibility determination apparatus according to claim 7, wherein the visibility is calculated as the visibility.

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