JP6386837B2 - Image processing program, information processing system, information processing apparatus, and image processing method - Google Patents

Description

  The present invention relates to an image processing program capable of processing an infrared image, an information processing system, an information processing apparatus, and an image processing method.

  Japanese Patent Laying-Open No. 2005-350010 (Patent Document 1) discloses a stereo-type vehicle exterior monitoring apparatus that monitors the surroundings of a host vehicle using a stereo camera configured by a pair of infrared cameras.

JP 2005-350010 A

  The configuration shown in the above prior art document calculates distance data using a stereo infrared camera, and monitors an object based on the calculated distance data. This prior art requires a stereo (that is, a plurality of) infrared cameras, and there is room for improvement in terms of mounting costs.

Said subject is achieved by the following structures, for example.
An image processing program according to an embodiment includes a computer, an image acquisition unit that acquires an infrared image of a subject, and the brightness and size of a predetermined area of the subject in the infrared image. It functions as a position determining means for determining the position.

  Preferably, the position determining means determines a relative position of the subject with reference to a predetermined position.

  More preferably, the position determining means determines a predetermined position from the infrared image corresponding to the subject positioned in the reference state.

  Preferably, the position determining unit determines the position of the subject based on the brightness of the predetermined area when the size of the predetermined area satisfies a predetermined condition.

  Preferably, the position determining unit determines the depth position of the subject in the imaging direction of the imaging unit from which the infrared image is acquired based on the brightness and size of the predetermined area.

  More preferably, the position determining means determines the position on the plane orthogonal to the direction of the subject based on the depth position and based on the position of the predetermined area in the infrared image.

  Preferably, the position determining unit includes a region specifying unit that specifies a region of the subject from the infrared image and specifies a predetermined region according to the specified region.

  More preferably, the area specifying unit specifies a predetermined area of the subject based on at least a part of a shape inherent to the subject.

  Preferably, the position determining unit determines the position of the subject when the brightness of the predetermined area and the size of the predetermined area satisfy a predetermined relationship.

  More preferably, the position determining means determines the position of the subject when the temporal change in brightness of the predetermined area and the temporal change in the size of the predetermined area maintain a predetermined relationship.

  Alternatively, more preferably, the position determination unit is configured to detect the position of the subject when the magnitude of the temporal change in the brightness of the predetermined area and the magnitude of the temporal change in the magnitude of the predetermined area maintain a predetermined relationship. To decide.

Preferably, the position determining means outputs a temporal change in the position of the subject.
Preferably, the image acquisition unit acquires an infrared image captured while irradiating the subject with infrared rays.

  An information processing system according to an embodiment generates an infrared image based on an imaging unit that captures infrared light of a subject and the brightness and size of a predetermined region of the subject in an infrared image obtained by imaging of the imaging unit. And a processing unit for determining the position of the included subject.

  An information processing apparatus according to an embodiment determines a position of a subject included in an infrared image based on image acquisition means for acquiring an infrared image of the subject and brightness and size of a predetermined region of the subject in the infrared image. Position determining means.

  An image processing method according to an embodiment includes a step of acquiring an infrared image of a subject, and a step of determining a position of the subject included in the infrared image based on brightness and size of a predetermined region of the subject in the infrared image. Including.

  According to the present embodiment, the configuration for determining the position of the subject can be realized at a lower cost.

It is a schematic diagram which shows the example of application of the image processing program of this Embodiment. It is a schematic diagram which shows the structural example of the information processing apparatus of this Embodiment. It is a figure for demonstrating the outline | summary of the position determination process performed by the image processing program of this Embodiment. It is a figure for demonstrating the outline | summary of the position determination process performed by the image processing program of this Embodiment. It is a flowchart which shows the process sequence of the position determination process provided by the image processing program of this Embodiment. It is a schematic diagram which shows some structural examples of the imaging part of the information processing apparatus of this Embodiment. It is a schematic diagram which shows the structural example of the imaging part carrying the infrared light projection function of the information processing apparatus of this Embodiment. It is a figure which shows the relationship between the distance from an imaging part to an object when the imaging condition is fixed, and the brightness of the infrared rays detected by the imaging part. It is a figure which shows the relationship between the brightness of a predetermined area | region, and the magnitude | size of a predetermined area | region. It is a figure which shows an example of the user interface for the calibration which the information processing apparatus of this Embodiment provides. It is a figure for demonstrating an example of the calculation process of the absolute position of this Embodiment. It is a figure for demonstrating an example of the correction process of the infrared image of this Embodiment. It is a figure for demonstrating an example of the specific process of a skin color area | region. It is a flowchart which shows the process sequence of the correction process of the infrared image provided by the image processing program of this Embodiment.

  This embodiment will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

<A. Application example>
First, an application example of the image processing program of the present embodiment will be described. FIG. 1 is a schematic diagram showing an application example of the image processing program of the present embodiment. With reference to FIG. 1, the image processing program of the present embodiment is executed in the information processing apparatus 1, and performs the processing described below on an image obtained by capturing an image of the subject, thereby Determine the position. In the present embodiment, an infrared image mainly including infrared information from a subject (hereinafter sometimes referred to as an “IR (Infrared) image”) is acquired, and processing is performed on the infrared image. . In the present specification, an infrared image includes at least one information of an infrared ray generated by being reflected by a subject and an infrared ray generated by the subject itself. Furthermore, it is sufficient if it mainly includes infrared information, and does not exclude an image including visible light information together with infrared information.

  As one application example, as shown in FIG. 1, a part of a user's body (for example, a hand or a finger) is imaged as a subject, and the position of the part of the user's body is set to a predetermined period or event. Decide every time. The determined position may be a relative position of the subject with reference to a predetermined position, or may be an absolute position from the information processing apparatus 1 (strictly speaking, the imaging unit 4).

  As a typical example of the information processing apparatus 1, in addition to a portable information processing apparatus (an example of a smartphone is shown in FIG. 1), a stationary information processing apparatus (for example, a personal computer or a television apparatus), a camera Etc. The information processing apparatus 1 includes an imaging unit 4 that captures infrared light of a subject. The imaging unit 4 may be able to acquire a non-infrared image in addition to the infrared image. Furthermore, the processing unit that executes various processes as will be described later and the imaging unit 4 can be configured as independent housings, and can be implemented as an information processing system by combining the two.

  The non-infrared image means an image mainly including information on light having a wavelength different from that of infrared rays from the subject, and typically includes a visible light image mainly including information on visible light from the subject. The visible light image may be output as an RGB image, a gray scale image, or a binary (monochrome) image. As the non-infrared image, an ultraviolet image mainly including ultraviolet information from the subject may be used.

  The information processing apparatus 1 shown in FIG. 1 has a display 2 on which information on the determined position of the subject and an execution state of an application using the determined position are displayed. The determined position may be input as information indicating the user's gesture, or the determined position may be directly used as an input value for game processing or the like.

<B. Configuration example>
Next, a configuration example of the information processing apparatus 1 will be described. FIG. 2 is a schematic diagram illustrating a configuration example of the information processing apparatus 1 according to the present embodiment. Referring to FIG. 2, an information processing apparatus 1 includes, as typical components, a display 2, an imaging unit 4, an input unit 6, a communication unit 8, a CPU (Central Processing Unit) 10, a DRAM (Dynamic Random Access Memory) 12 and flash memory 14.

  The imaging unit 4 receives light from the subject and outputs an image showing the subject. In the present embodiment, the imaging unit 4 outputs an infrared image of the subject. The infrared image mainly includes infrared information from the subject. In addition, the imaging unit 4 may output a non-infrared image mainly including information on light having a wavelength different from that of infrared rays from the subject. That is, you may employ | adopt the imaging part 4 which images the infrared light of a to-be-photographed object, and the light of a wavelength different from the infrared rays from the said to-be-photographed object.

  The display 2 is a device that notifies the user of various types of information, and is mounted using an LCD (Liquid Crystal Display), an organic EL (ElectroLuminescence) display, or the like.

  The input unit 6 is a device that accepts instructions and operations from a user or the like, and may be implemented as various buttons and switches provided on the housing of the information processing apparatus 1, or a touch panel that is disposed integrally with the display 2. May be implemented as

  The communication unit 8 is a device that mediates communication with other devices, and includes mobile communication components such as LTE (Long Term Evolution) and 3G (third generation), wireless LANs that comply with the IEEE 802.11n standard, and Bluetooth (registration). (Trademark), IRDA (Infrared Data Association) and other short-range communication components.

  The CPU 10 is an example of a processor that executes various programs, and constitutes a main part of the processing unit. The DRAM 12 functions as a working memory that temporarily holds data necessary for the CPU 10 to execute various programs. The flash memory 14 is a storage device that holds various data in a nonvolatile manner, and typically stores an image processing program 16 and various application programs 18. These programs are read out and expanded in the DRAM 12 and then executed by the CPU 10.

  The hardware and software constituting the information processing apparatus 1 are not limited to those shown in FIG. For example, the external server device may have all or part of the functions of the information processing apparatus 1. That is, instead of the single information processing apparatus 1, an information processing system including a terminal and one or more servers may be used. In this case, each means of the information processing system is realized by processing by the processor of the terminal, processing by the processor of the external server device, or cooperative processing by the processor of the terminal and the processor of the external server device. The sharing of processing can be appropriately designed according to the common general technical knowledge of those skilled in the art.

  The image processing program 16 executed in the information processing apparatus 1 is not limited to that provided by a storage medium, and may be provided by downloading via a network such as the Internet.

<C. Overview of positioning process>
Next, an outline of the position determination process executed by the image processing program of the present embodiment will be described. In the position determination process of the present embodiment, the position of the subject (part of interest) is determined from information on an image (representation) indicating the subject included in the acquired infrared image. A portion (real object) of a subject whose position is to be determined is hereinafter referred to as an “object”, and an area corresponding to the “object” in the infrared image is referred to as an “object area”.

  The brightness (illuminance) and size of the object area in the infrared image obtained by imaging the object by the imaging unit 4 have a correlation with the following factors. More specifically, the brightness of the object area is proportional to the following factors.

・ Infrared brightness (illuminance / intensity) applied to the subject
-Exposure time of imaging unit-Surface reflectance of object-(Distance from imaging unit 4 to object) ^-2
The size (size) of the object area is inversely proportional to the distance from the imaging unit 4 to the object.

  The position determination process of the present embodiment uses such a physical relationship, and based on the brightness and size of a predetermined area of the subject in the infrared image, the object (subject) included in the infrared image Determine the position. The predetermined area corresponds to an area including at least a part of an area representing an object (that is, an object area), and can be specified based on at least a part of a shape inherent to the subject (object).

  In this embodiment, by using an infrared image mainly including infrared information from the subject, the position can be determined with higher accuracy than when using a visible light image mainly including information about visible light from the subject. Can be determined.

  3 and 4 are diagrams for explaining the outline of the position determination process executed by the image processing program of the present embodiment. 3 and 4 show examples of infrared images acquired when the user's hand is an object, as an example. As shown in FIG. 3, when the distance from the imaging unit 4 to the object is relatively close, the object region in the infrared image becomes relatively bright (the illuminance becomes high), and the range is relatively Become bigger (wider). On the other hand, when the distance from the imaging unit 4 to the object is relatively long, the object region in the infrared image is relatively dark (the illuminance is low), and the range is relatively small ( Narrow).

  Based on the brightness (illuminance / intensity) and size (size) of the object region appearing in such an infrared image, it is determined whether the object has approached or moved away from a predetermined position. Hereinafter, as a typical example, a method for calculating the distance (relative distance) between the imaging unit 4 and the object based on the position (reference position) of the object (subject) positioned in the reference state will be described.

  FIG. 4 is a diagram illustrating an example of an infrared image captured when the object is in the reference state. Referring to FIG. 4, the user places his / her hand in a position where it will be used in a normal operation, and receives some trigger to acquire an infrared image. The trigger may be input directly by the user, or may be triggered by repeatedly acquiring an infrared image and performing some image processing and satisfying a predetermined condition.

  When the infrared image in the reference state is acquired, an object region (the contour of the hand in the example of FIG. 4) is specified from the infrared image. A predetermined area 30 is set according to the specified object area. From the illuminance of each pixel included in the predetermined region 30, the representative value (initial value) of illuminance at the reference position is determined. The average value of the illuminance of all the pixels included in the predetermined area 30 can be calculated as a representative value (initial value). In the calculation of the representative value, an abnormal value of illuminance included in the predetermined area 30 may be excluded.

  The procedure for acquiring the reference position and the initial information (for example, representative value) related to the reference position including the processing shown in FIG. 4 is also referred to as “calibration” below.

  For example, the distance from the imaging unit 4 to the object is set to “1” for the predetermined region 30 in the infrared image 32 shown in FIG. At this time, it is assumed that the calculated average value of brightness is “100” and the size (size) of the predetermined area 30 is “100 × 100” pixels.

  In the infrared image 34 shown in FIG. 3 (when close), a hand is placed at a position that is “0.7” times the distance from the imaging unit 4 to the object at the time of imaging the infrared image 32 (FIG. 4). In this case, the size (size) of the predetermined region 30 is calculated as “160 × 160” pixels, and the average value of brightness is calculated as “204”.

  On the other hand, the infrared image 36 shown in FIG. 3 (when far) is in a position that is “2.0” times as long as the distance from the imaging unit 4 to the object at the time of imaging the infrared image 32 (FIG. 4). In this case, the size (size) of the predetermined region 30 is calculated as “60 × 60” pixels, and the average value of brightness is calculated as “25”.

  FIG. 5 is a flowchart showing the processing procedure of the position determination process provided by the image processing program of the present embodiment. Each step shown in FIG. 5 is typically realized by the CPU 10 executing the image processing program 16 (FIG. 2).

  Referring to FIG. 5, first, calibration shown in steps S2 to S10 is performed. Specifically, the CPU 10 acquires an infrared image of the subject (step S2). At this time, it is assumed that the object (subject) whose position is to be determined is in the reference state. Acquisition of an infrared image is implement | achieved when CPU10 gives a command to the imaging part 4 (FIG. 2).

  Subsequently, the CPU 10 specifies an object area (subject area) from the infrared image (step S4), and sets a predetermined area according to the specified object area (step S6). The CPU 10 calculates a representative value of illuminance from the illuminance of each pixel included in the specified predetermined area (step S8). The representative value of illuminance is stored as an initial value of illuminance at the reference position. Then, the CPU 10 stores the calculated representative illuminance value (brightness of the predetermined area) and the size of the predetermined area as a result of calibration (step S10).

  In the calibration, the brightness and size of a predetermined area corresponding to the position (reference position) of the object (subject) in the reference state are determined, and the relative position of the object is sequentially determined based on the position in the reference state. . That is, according to the following procedure, the CPU 10 determines the position of the subject included in the infrared image based on the brightness and size of a predetermined area in the infrared image.

  Specifically, the CPU 10 acquires a new infrared image (step S12). Then, the CPU 10 newly specifies an object area (subject area) from the infrared image (step S14), and sets a predetermined area according to the specified object area (step S16). Subsequently, the CPU 10 calculates a representative value of the illuminance of the predetermined area (brightness of the predetermined area) from the illuminance of each pixel included in the predetermined area specified in step S16 (step S18), and calculates the calculated predetermined area. It is determined whether the brightness and size satisfy a predetermined condition (step S20).

  When the brightness and size of the predetermined area satisfy the predetermined condition (YES in step S20), the CPU 10 calculates the predetermined area based on the brightness of the predetermined area acquired in the calibration. The position of the object is determined from the brightness of the area (step S22). Subsequently, the CPU 10 executes predetermined post-processing according to the determined position of the object (step S24). That is, the position determination function of the information processing apparatus 1 determines the position of the object (subject) when the brightness of the predetermined area and the size of the predetermined area satisfy a predetermined relationship.

  On the other hand, when the brightness and size of the predetermined area do not satisfy the predetermined condition (NO in step S20), the CPU 10 executes an error process (step S26).

  The CPU 10 determines whether or not the end of the position determination process is instructed (step S28). If the end of the position determination process is not instructed (NO in step S28), the processes in and after step S12 are repeated. On the other hand, if the end of the position determination process is instructed (YES in step S28), the position determination process ends.

<D. Infrared image acquisition processing and acquisition mechanism>
Next, a process for acquiring an infrared image and a mechanism used for the process will be described.

(D1: Image sensor)
FIG. 6 is a schematic diagram illustrating some configuration examples of the imaging unit 4 of the information processing apparatus 1 according to the present embodiment. FIG. 6A shows a configuration example using a Bayer array image sensor including an IR filter, and FIG. 6B generates an infrared image (IR image) and a non-infrared image (RGB image), respectively. It is a figure which shows the structural example which provided the image pick-up element to perform separately.

  The image sensor shown in FIG. 6A is obtained by replacing one G filter of four color filters (R + G × 2 + B) with an IR filter in a general Bayer array image sensor. The IR filter has transmission characteristics with respect to infrared rays, and the infrared rays from the subject are incident on a detection element associated with the IR filter, and the illuminance thereof is detected. Each detection element associated with each of the R, G, and B filters detects the illuminance of visible light from the subject. An IR image is generated based on information from each detection element associated with the IR filter, and an RGB image is generated based on information from each detection element associated with each of the R, G, and B filters. .

  That is, in the configuration example illustrated in FIG. 6A, the information processing apparatus 1 acquires an infrared image and a non-infrared image from an image sensor with a Bayer array including an IR filter.

  On the other hand, in the configuration example shown in FIG. 6B, a compound eye type optical system is used. That is, the reflected light from the subject is guided to the image sensors 43 and 44 through the lenses 41 and 42, respectively. It is assumed that an IR filter (not shown) is associated with the image sensor 43 and a color (RGB) filter (not shown) is associated with the image sensor 44. Thereby, the image sensor 43 generates an infrared image (IR image), and the image sensor 44 generates a non-infrared image (RGB image).

  As another configuration example, a configuration in which an independent image sensor is arranged for each of R, G, and B may be employed. In this case, a total of four image sensors of R, G, B, and IR are arranged. A plurality of image sensors may be arranged with a common lens.

  By employing any of the above-described configurations, an infrared image and a non-infrared image (typically an RGB image) can be simultaneously acquired from the same subject.

(D2: Infrared projection function)
Next, the infrared light projection function will be described. An infrared image is mainly generated from information on infrared rays from a subject. However, in a general use environment, the amount of infrared rays incident on the subject is often insufficient. Therefore, it is preferable to mount an infrared light projection function as a function of the imaging unit 4. That is, as the image acquisition function of the information processing apparatus 1, it is preferable to acquire an infrared image captured while irradiating the subject with infrared rays.

  FIG. 7 is a schematic diagram illustrating a configuration example of the imaging unit 4 equipped with the infrared light projection function of the information processing apparatus 1 according to the present embodiment. Referring to FIG. 7, in addition to a lens 41 that guides light from the subject to the image sensor 43, an irradiation unit 45 that irradiates the subject with infrared rays is provided. The irradiation unit 45 has an infrared generation unit such as an infrared LED or an infrared lamp, and irradiates the generated infrared toward the subject. The exposure timing by the image sensor 43 and the light emission timing by the irradiation unit 45 are synchronized.

  Since the imaging condition can be stabilized by installing such a light projecting function, the accuracy of determining the position of the object can be increased.

  Note that the irradiation unit 45 may have a function similar to that of a general flash as well as infrared rays. That is, the irradiation unit 45 may be configured to irradiate the subject with infrared rays and visible rays simultaneously.

(D3: Control depending on the distance from the imaging unit to the object)
FIG. 8 is a diagram illustrating the relationship between the distance from the imaging unit 4 to the object and the brightness of infrared rays detected by the imaging unit 4 when the imaging condition is constant. The unit of distance and brightness is an arbitrary unit. As described above, the brightness of the object area in the infrared image is inversely proportional to the square of (distance from the image capturing unit 4 to the object), and therefore, as the object moves away from the image capturing unit 4, as illustrated in FIG. The brightness of infrared rays detected by the unit 4 gradually decreases. Further, the change in distance corresponding to the change in the detected brightness per unit increases as the distance increases. This means that the distance calculation sensitivity (ie, resolution) decreases as the object moves away from the imaging unit 4. In the characteristic example shown in FIG. 8, when the distance is less than 20, there is about 0.5 resolution, and when the distance is 20 to 40, there is about 1 resolution, but the distance is 40. In this case, only a resolution of about 2.5 can be obtained.

  Further, since the detectable range of the infrared brightness in the imaging unit 4 is limited to a finite gradation value (typically 0 to 255 gradations), the exposure time (shutter speed) in the imaging unit 4 is limited. ) And the brightness and / or time of infrared rays emitted from the irradiation unit 45 are preferably changed depending on the distance from the imaging unit 4 to the object. For example, a known automatic exposure (AE) function can be used.

  More specifically, the image acquisition function (CPU 10) of the information processing apparatus 1 gives a control command to the irradiation unit 45 so that stronger infrared rays are emitted as the distance to the subject increases. That is, when the distance from the imaging unit 4 to the object is relatively long, the brightness of the infrared rays incident on the imaging unit 4 is relatively small, and thus a stronger infrared ray is emitted.

  Further, the image acquisition function (CPU 10) of the information processing apparatus 1 gives a control command so that the exposure time of the imaging unit for acquiring the infrared image becomes longer as the distance to the subject becomes longer. That is, when the distance from the imaging unit 4 to the object is relatively long, the brightness of the infrared rays incident on the imaging unit 4 is relatively small, so that the infrared rays are incident for a longer time. Control the exposure time at.

  Note that the distance from the imaging unit 4 to the object can be determined using the determination result of the distance of the past object. Typically, the imaging conditions (infrared irradiation time / irradiation intensity and exposure time) may be determined using the distance determined in the previous calculation cycle.

(D4: Exposure method of the imaging unit 4)
As an exposure method for the imaging unit 4, either a rolling shutter method or a global shutter method may be used. Since the rolling shutter method is sequential scanning, it consumes relatively little power and is suitable for a portable information processing apparatus. On the other hand, since the exposure time is relatively short in the global shutter method, it is possible to appropriately capture a subject that moves rapidly.

<E. Details of the position determination process>
(E1: Identification of object area (subject area) (steps S4 and S14))
As a method for specifying an object region, for example, a method of extracting an outer shape from a feature point of illuminance distribution in an infrared image (for example, an edge point where illuminance changes greatly), or the like, based on other feature amounts included in the infrared image A method of extracting a region or an outer shape, a method of extracting based on at least a part of a shape inherent to a subject (object), or the like can be used.

  In the example shown in FIG. 3 and FIG. 4 described above, since the hand (palm) is an object, the object area is determined by searching for a unique shape of the hand (for example, a part showing five fingers, respectively). Can be identified. That is, the contour (or outer shape) of the hand can be specified from the feature amount in the infrared image.

(E2: Setting a predetermined area according to the object area (steps S6 and S16))
A predetermined area is set according to the object area corresponding to the identified hand. The predetermined area is not limited to a rectangle, and an outline (object area) indicating a feature amount may be used as it is. If the shape of an object is known, a shape similar to the known shape is used. May be. Furthermore, the predetermined area may be set so as to include an area outside the object area.

  In the example shown in FIGS. 3 and 4, it is preferable to set the area corresponding to the palm of the user as the predetermined area 30. That is, it is preferable to exclude the finger of the user's hand from the predetermined area 30. Since the finger of the hand has a relatively large temporal movement and the calculated illuminance is not stable, it is preferable to exclude these. In addition, the brightness of the infrared rays reflected from the subject depends on the reflectance of the subject surface, but the finger's finger moves and the reflectance changes relatively greatly. Unsuitable. For this reason, in order to increase the accuracy of position determination, it is preferable to exclude such a portion having a large movement.

(E3: Validity of brightness of predetermined area and size of predetermined area (step S20))
In the position determination process of the present embodiment, basically, the position of the object is determined based on the representative value calculated from the illuminance of the pixels included in the predetermined area. At this time, there may be a case where an object other than the object of interest is reflected in the infrared image, and the position may be erroneously determined by a partial image generated by such an object. Therefore, the determination of such an incorrect position is avoided using the following conditions. Note that all of the following conditions may be used, or only a part may be used.

(1) The brightness of the predetermined area and the size of the predetermined area satisfy a predetermined relationship As one condition, it is determined whether or not the brightness of the predetermined area and the size of the predetermined area satisfy a predetermined relationship. When the above relationship is satisfied, the position of the subject may be determined based on the brightness of the predetermined area.

  As described above, the brightness of the object region is inversely proportional to the square of the distance from the imaging unit 4 to the object, and the size of the object region is inversely proportional to the distance from the imaging unit 4 to the object. Therefore, a predetermined relationship between the brightness of the predetermined area and the size of the predetermined area that is originally set according to the object area is maintained.

  FIG. 9 is a diagram illustrating the relationship between the brightness of a predetermined area and the size of the predetermined area. FIG. 9A conceptually shows the result when the state in which the object is separated from the imaging unit 4 can be detected appropriately, and FIG. 9B shows the state in which the object is separated from the imaging unit 4 appropriately. The result when it cannot be detected is shown conceptually.

  As shown in FIG. 9A, when the object moves away from the imaging unit 4, both the brightness of the predetermined area and the size of the predetermined area are reduced. On the other hand, when the object approaches the imaging unit 4, the brightness of the predetermined area and the size of the predetermined area both increase. On the other hand, when an error factor occurs in the infrared image, a change different from the original change is detected as shown in FIG.

  It is preferable to determine whether or not appropriate detection has been performed using the relationship between the brightness of the predetermined area and the size of the predetermined area.

  More specifically, it is determined whether or not the predetermined relationship between the temporal change in brightness of the predetermined region and the temporal change in the size of the predetermined region is maintained, and the predetermined relationship is maintained. The position of the object may be determined when That is, it is determined whether or not the brightness change direction (increase / decrease) in the predetermined area matches the temporal change (increase / decrease) in the size of the predetermined area. The position of the object is calculated assuming that it is properly detected. In other words, whether or not appropriate detection has been performed based on the coincidence / mismatch of the sign (change direction) between the temporal change in brightness of the predetermined area and the temporal change in the size of the predetermined area. Judgment can be made.

  Alternatively, the predetermined relationship is maintained by determining whether or not a predetermined relationship between the magnitude of the temporal change in luminance of the predetermined region and the temporal change in the size of the predetermined region is maintained. Sometimes the position of the object may be determined. That is, the ratio between the amount of change in brightness of the predetermined area per unit time (increase / decrease) and the amount of change in the size of the predetermined area per unit time (increase / decrease) is within the predetermined range. If it is within a predetermined range, the position of the object is calculated assuming that it is properly detected. In other words, whether or not appropriate detection has been performed based on the divergence state of the value between the amount of change in brightness of the predetermined area per unit time and the amount of change in the size of the predetermined area per unit time. Judgment can be made.

(2) The size of the predetermined area satisfies the predetermined condition In place of / in addition to the above-described method of paying attention to the relative relationship between the brightness of the predetermined area and the size of the predetermined area, the size of the predetermined area itself May determine whether or not a predetermined condition is satisfied, and when the predetermined condition is satisfied, the position of the subject may be determined based on the brightness of the predetermined area.

  More specifically, it is determined whether the size of the predetermined area detected is too large or too small compared to the size (reference value) of the predetermined area acquired in the calibration. Thus, it can be determined whether or not appropriate detection has been performed. That is, it is determined whether the ratio or difference of the detected size of the predetermined area with respect to the size (reference value) of the predetermined area acquired in the calibration is within the predetermined range. The object position may be calculated on the assumption that the object is properly detected only when it is within the object.

(E4: Distance calculation and plane position (step S22))
Since the brightness of the predetermined area is inversely proportional to the square of the distance from the imaging unit 4 to the object, if the brightness of the predetermined area is calculated to be B at a certain time, the brightness of the imaging unit 4 and the object at that time The distance L between can be expressed as follows.

L = L0 × √ (B0 / B)
However, L0 is the distance between the imaging unit 4 and the object acquired by calibration, and B0 is the brightness of the predetermined area acquired by calibration.

  Here, if L0 = 1, the relative distance between the imaging unit 4 and the object can be calculated using the brightness B0 of the predetermined area acquired by calibration. This relative distance indicates a depth position in the imaging direction (camera direction: z direction) of the imaging unit 4. Further, the position where the predetermined region in the infrared image exists indicates a position (x coordinate and y coordinate) on a plane orthogonal to the imaging direction of the imaging unit 4. Thus, in the present embodiment, the depth position of the object in the imaging direction of the imaging unit 4 that is the acquisition source of the infrared image is determined based on the brightness and size of the predetermined area. That is, the depth position is determined, and the position on the plane orthogonal to the imaging direction of the object is determined based on the position of the predetermined region in the infrared image.

  Finally, the x-coordinate, y-coordinate, and z-coordinate of the object defined in the coordinate system based on the viewpoint of the imaging unit 4 are output for each calculation cycle.

(E5: continuous output (step S24))
As described above, the information processing apparatus 1 calculates the three-dimensional coordinates of the object for each calculation cycle, and acquires the temporal behavior of the object from the three-dimensional coordinates output in time series. That is, the information processing apparatus 1 outputs a temporal change in the position of the object. By using such a temporal change in position, it is possible to determine a gesture performed by the user and to proceed with various game processes.

<F. Calibration>
It is necessary to perform calibration with the object (subject) as a reference state. The reference state may be any state, but if the object is too close to the imaging unit 4 or too far from the imaging unit 4, the accuracy of position determination is reduced, and thus the range in which the object can move It is preferable to calibrate at an intermediate point. Therefore, a user interface that supports such calibration may be provided.

  FIG. 10 is a diagram illustrating an example of a user interface for calibration provided by the information processing apparatus 1 according to the present embodiment. Referring to FIG. 10, a guide 70 for positioning the subject in the reference state is displayed on the display 2 of the information processing apparatus 1, and the user can make the captured hand fit in the guide 70. The positional relationship between the user and / or his / her hand and the imaging unit 4 is adjusted. When the user's hand fits in the guide 70, the user operates the OK button 72 displayed on the display 2 with the other hand, whereby an infrared image for calibration is acquired and calibration is executed.

  By displaying such a guide, calibration can be executed more appropriately and easily.

<G. Absolute position calculation processing>
In the above description, the processing example in which the relative position of the object is sequentially determined based on the position in the reference state has been described. If the absolute position (absolute distance) in the reference state can be acquired, the absolute position, not the relative position, can be calculated in a pseudo manner.

  As one of the methods for acquiring the absolute position (absolute distance) in the reference state, the relationship between the size of the object region appearing in the infrared image and the absolute position is acquired in advance using the imaging unit 4 of the information processing apparatus 1. There is a method using this relationship. Specifically, the size of the object region and the absolute distance from the imaging unit 4 are obtained from an infrared image obtained by arranging and imaging samples having a known size in advance at a plurality of positions using the imaging unit 4. Can be defined. In calibration, an image of a sample with a known size (for example, a stylus attached to the information processing apparatus 1) is imaged, and the size of the imaged sample in an infrared image is evaluated. The absolute distance can be determined.

  When the user's hand or the like is an object, the average size is known in advance, and the absolute value at the time of calibration may be determined in a pseudo manner using the average value.

  FIG. 11 is a diagram for explaining an example of an absolute position calculation process according to the present embodiment. Referring to FIG. 11, the size and absolute position of the object region appearing in the previously acquired infrared image are determined by specifying the contour of the hand from the feature quantity in the infrared image and calculating the size of the hand. The position where the hand exists (depth position) may be calculated by referring to the relationship.

<H. Infrared image correction>
In the processing for determining the position of the object described above, an object region in the infrared image is specified and a predetermined region is set (steps S4, S6, S14, and S16 in FIG. 5). In such processing, it is preferable to acquire an infrared image showing only the object. However, when there is an object that emits infrared rays in the background of the object when the object is imaged, the infrared rays from such an object enter the infrared image as noise. In such a case, it is preferable to specify the object region after performing some correction (pre-processing) on the infrared image.

  In the following, processing when a non-infrared image is used as such infrared image correction processing will be described. That is, the information processing apparatus 1 according to the present embodiment includes an infrared image mainly including infrared information from the object (subject) and a non-infrared image mainly including information on light having a wavelength different from that of the infrared rays from the object (subject). And a correction function for correcting the infrared image based on the feature amount of the non-infrared image.

  FIG. 12 is a diagram for explaining an example of the infrared image correction processing according to the present embodiment. Referring to FIG. 12, when an infrared image 60 is acquired by capturing an object, an RGB image 50, which is an example of a non-infrared image, is acquired. As will be described later, since processing for superimposing the images between the RGB image 50 and the infrared image 60 is required, imaging of a Bayer array including an IR filter as shown in FIG. 6A described above is performed. It is preferable to acquire these two images using an element. Although a compound eye type configuration as shown in FIG. 6B may be employed, in this case, correction according to the parallax existing between the optical systems is required.

  The non-infrared image is not limited to an RGB image, and an ultraviolet image may be used, or a gray image (single color image) focused on only one of R, G, and B may be used.

  As shown in the RGB image 50 and the infrared image 60 in FIG. 12, the luminance information of the objects that can be acquired is different from each other due to the difference in the detected wavelengths. Using such a difference in acquired luminance information, correction is performed so that only object information can be extracted.

  First, a feature value reflecting an object is calculated from a non-infrared image. If the non-infrared image is the RGB image 50 and the object is a user's hand, for example, a skin color detection process can be used. That is, the skin color area included in the RGB image 50 is specified. The result image 52 shows the result after the skin color detection is performed on the RGB image 50. The result image 52 is obtained by converting a pixel determined to be a skin color into “1” (white) and converting other pixels into “0” (black). That is, in the infrared image correction process, the feature amount is obtained by binarizing the non-infrared image.

  FIG. 13 is a diagram for explaining an example of the skin color area specifying process. Referring to FIG. 13, in order to specify the skin color area, the color coordinate system of the RGB image is converted from the RGB coordinate system to the YUV coordinate system. Then, an image existing in a region (space) on the color coordinate system that can be regarded as a predefined “skin color” is extracted from the YUV image converted into the YUV coordinate system. The “skin color” can be more accurately determined by using the YUV coordinate system.

  As described above, the correction process of the information processing apparatus 1 includes a process of specifying the skin color region of the object (subject) from the RGB image and correcting the infrared image 60 based on the skin color region.

  Referring to FIG. 12 again, the binarized infrared image 62 is generated by performing binarization processing on the infrared image 60 using the predetermined brightness as a threshold value. Finally, a corrected infrared image 64 is generated by calculating a product for each corresponding pixel between the result image 52 and the binarized infrared image 62. That is, as the correction process, a process of multiplying each pixel value of the binarized non-infrared image (result image 52) by each pixel value of the infrared image is executed. This processing means that only pixels whose corresponding pixel in the result image 52 is “1” (skin color region) among the pixels constituting the binarized infrared image 62 are output as effective pixels. .

  The infrared image 60 does not necessarily need to be binarized, and the infrared image 60 can be corrected by multiplying each pixel value of the infrared image 60 by using the result image 52 as a kind of mask image.

  As described above, the information processing apparatus 1 corrects the infrared image 60 based on the feature amount (skin color region in the example illustrated in FIG. 12) of the non-infrared image (RGB image 50). The feature amount of the non-infrared image is basically a feature amount that cannot be obtained from the infrared image.

  The correction process for the infrared image 60 includes a process for ignoring the region other than the region where the object (subject) of the infrared image 60 exists. In other words, the correction means for the infrared image 60 includes a process of extracting only a region where the object (subject) of the infrared image 60 exists. The series of correction processes specifies a region where an object exists in the image from the non-infrared image (RGB image 50), and effective information indicating the object (subject) included in the infrared image 60 according to the specified region. Is used selectively. In this way, by selectively using effective information indicating the object (subject) included in the infrared image 60, the object region in the infrared image can be specified more accurately.

  Furthermore, a process for specifying an object region may be further executed by searching for a unique shape of the object using the RGB image 50 and / or the result image 52 shown in FIG. That is, the outline (or outline) of the hand or the position of the finger may be specified from the feature amount in the image as described above. By further executing the shape specifying process for specifying the shape of the object (subject) included in the non-infrared image (RGB image 50 and / or result image 52), noise that has moved into the non-infrared image is generated. The resulting component (in the RGB image 50 of FIG. 12, the light from the background illumination) can be removed.

  By further adding such a shape specifying process, it is possible to more accurately select effective information indicating an object (subject) included in the infrared image 60 and more accurately specify an object region in the infrared image. That is, the correction processing of the information processing apparatus 1 includes shape specifying processing for specifying the shape of the subject included in the non-infrared image (RGB image 50 and / or result image 52), and based on the feature amount in the specified shape. The infrared image 60 is corrected.

  Various processes may be executed after performing another correction on the infrared image 60 and / or the RGB image 50 before correction using the corrected infrared image 64. For example, an object region is specified from the corrected infrared image 64, and only information related to the object is extracted using the image (information) of the region in the infrared image 60 or the RGB image 50 corresponding to the specified object region. It may be. As described above, the information processing apparatus 1 can be provided with a function of reflecting the information of the infrared image corrected by the correction process in the infrared image or the non-infrared image before correction.

  FIG. 14 is a flowchart showing a processing procedure of infrared image correction processing provided by the image processing program of the present embodiment. Each step shown in FIG. 14 is typically realized by the CPU 10 executing the image processing program 16 (FIG. 2).

  Referring to FIG. 14, first, CPU 10 acquires an infrared image and a non-infrared image of a subject (step S100). At this time, in the case of using the imaging unit 4 using the Bayer-arrayed imaging device as shown in FIG. 6A, by giving an imaging command to the imaging unit 4, an infrared image and a non-infrared image are simultaneously displayed. You can get it. On the other hand, in the case of using the image pickup unit 4 in which the image pickup devices as shown in FIG. 6B are individually provided, an infrared image and a non-infrared image are provided by giving an image pickup command to each image pickup device. To get.

  Subsequently, the CPU 10 calculates a feature amount reflecting the object from the non-infrared image (step S102). Typically, the CPU 10 performs a skin color detection process on the RGB image 50 which is an example of a non-infrared image, and specifies a skin color region. In parallel with the process of step S102, the CPU 10 performs a binarization process on the infrared image 60 to generate a binarized infrared image 62 (step S104).

  Then, the CPU 102 multiplies each pixel of the binarized infrared image 62 by the feature amount calculated in step S102 to generate a corrected infrared image 64 (step S106). The position determination process shown in FIG. 5 may be executed using the corrected infrared image 64 generated in step S106.

<I. Advantage>
In the present embodiment, an object area representing an object in the infrared image is specified, and a predetermined area is set according to the object area. Since the position of the object included in the infrared image is determined based on the set brightness and size of the predetermined area, it is sufficient to have one imaging unit, and the mounting cost can be reduced. In addition, since the brightness and size of a predetermined area in the infrared image acquired for each frame is used, the amount of calculation required for distance calculation can be reduced, and higher-speed processing can be realized.

  In the present embodiment, using the non-infrared image, information on an object other than the object is removed / reduced from the infrared image, and the position and movement of the object are detected. Thereby, it can suppress that the position of an object etc. are determined accidentally by the information of objects other than an object.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Information processing apparatus, 2 Display, 4 Imaging part, 6 Input part, 8 Communication part, 10 CPU, 12 DRAM, 14 Flash memory, 16 Image processing program, 18 Application program, 41, 42 Lens, 43, 44 Image sensor, 45 Irradiation part.

Claims (19)

An image processing program for obtaining an infrared image of a subject from a computer;
Based on the brightness and size of a predetermined area of the subject in the infrared image, function as position determining means for determining the position of the subject included in the infrared image ,
The position determining means is an image processing program for outputting a temporal change in the position of the subject . An image processing program for obtaining an infrared image of a subject from a computer;
Based on the brightness and size of a predetermined area of the subject in the infrared image, function as position determining means for determining the position of the subject included in the infrared image ,
Said position determining means and time change brightness of the predetermined area, when the magnitude of the temporal change in the predetermined region and maintains the predetermined relationship, that determine the position of the object, Image processing program. An image processing program for obtaining an infrared image of a subject from a computer;
Based on the brightness and size of a predetermined area of the subject in the infrared image, function as position determining means for determining the position of the subject included in the infrared image ,
The position determining means determines the position of the subject when the magnitude of the temporal change in the brightness of the predetermined area and the magnitude of the temporal change in the size of the predetermined area maintain a predetermined relationship. that determine, image processing program. The image processing program according to claim 2 , wherein the position determining unit outputs a temporal change in the position of the subject. The image processing program according to any one of claims 1 to 4, wherein the position determining means determines a relative position of the subject with reference to a predetermined position. The image processing program according to claim 5 , wherein the position determining unit determines the predetermined position from an infrared image corresponding to the subject positioned in a reference state. Said position determining means, the size of the predetermined area is when a predetermined condition is satisfied, based on the brightness of the predetermined region, to determine the position of the object, any one of the claims 1-6 The image processing program according to item. Said position determining means, based on the brightness and size of the predetermined area to determine the depth position of the object in the imaging direction of the acquisition target is a imaging portion of the infrared image, claim 1-7 The image processing program according to item 1. Said position determining means is configured to determine the depth position based on the position of the predetermined region in the infrared image, determining the position on the surface orthogonal to the capturing direction of the subject, according to claim 8 Image processing program. Said position determining means, the addition to identifying an area of the object from the infrared image, including area specifying means for specifying a predetermined region in response to the said specific region, according to any one of claims 1-9 Image processing program. The image processing program according to claim 10 , wherein the area specifying unit specifies a predetermined area of the subject based on at least a part of a shape inherent to the subject. It said image acquisition means acquires an infrared image captured while irradiating infrared rays onto the object, an image processing program according to any one of claims 1 to 11. An imaging unit for imaging infrared light of a subject;
A processing unit that determines the position of the subject included in the infrared image based on the brightness and size of a predetermined region of the subject in the infrared image obtained by imaging of the imaging unit ;
Wherein the processing unit, you output the temporal change in the position of the object, the information processing system. An imaging unit for imaging infrared light of a subject;
A processing unit that determines the position of the subject included in the infrared image based on the brightness and size of a predetermined region of the subject in the infrared image obtained by imaging of the imaging unit ;
Wherein the processing unit, temporal change and brightness of the predetermined area, when said predetermined area size and temporal variation maintains a predetermined relationship, that determine the position of the object, information Processing system. An imaging unit for imaging infrared light of a subject;
A processing unit that determines the position of the subject included in the infrared image based on the brightness and size of a predetermined region of the subject in the infrared image obtained by imaging of the imaging unit ;
The processing unit determines the position of the subject when the magnitude of the temporal change in brightness of the predetermined area and the magnitude of the temporal change in the predetermined area maintain a predetermined relationship. you, an information processing system. Image acquisition means for acquiring an infrared image of the subject;
Position determining means for determining the position of the subject included in the infrared image based on the brightness and size of a predetermined area of the subject in the infrared image ;
It said position determining means, you output the temporal change of the position of the object, the information processing apparatus. Obtaining an infrared image of the subject;
Determining the position of the subject included in the infrared image based on the brightness and size of a predetermined area of the subject in the infrared image ;
The step of determining the position of the subject includes the step of outputting a temporal change in the position of the subject . Obtaining an infrared image of the subject;
Determining the position of the subject included in the infrared image based on the brightness and size of a predetermined area of the subject in the infrared image ;
The step of determining the position of the subject includes determining the position of the subject when a temporal change in brightness of the predetermined area and a temporal change in the size of the predetermined area maintain a predetermined relationship. An image processing method including the step of determining . Obtaining an infrared image of the subject;
Determining the position of the subject included in the infrared image based on the brightness and size of a predetermined area of the subject in the infrared image ;
The step of determining the position of the subject is performed when the magnitude of temporal change in brightness of the predetermined area and the magnitude of temporal change in the magnitude of the predetermined area maintain a predetermined relationship. An image processing method including a step of determining a position of a subject .