JP2012095229A - Image display device and computer program for image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device capable of displaying a moving image with image quality depending on the visual line direction of a user.SOLUTION: An image display device comprises: a display 111 that displays a moving image in a display area; a visual line direction detection unit 116 that detects the visual line direction of a user; a gaze determination unit 117 that determines whether the moving image is gazed at based on the visual line direction; a visual line movement determination unit 118 that determines a movement direction of the visual line direction; a movement direction determination unit 119 that determines whether the movement direction is a direction from outside of the display area toward the display area; and a display image switching unit 120 that, based on a determination result by the gaze determination unit 117, sets a display target to a high-load moving image when the moving image is gazed at, on the other hand, sets the display target to a low-load moving image when the moving image is not gazed at, and even when the moving image is not gazed at, if the visual line direction is moved toward the display area, switches the display target from the low-load moving image to the high-load moving image.

Description

  The present invention relates to an image display device and a computer program for the image display device, and more particularly to improvement of an image display device that displays a moving image in a predetermined display area.

  In recent years, as a technique for reproducing a moving image, streaming that displays a stream image composed of moving image packets while sequentially receiving moving image packets from a server on a communication network such as the Internet is known. Recently, a mobile phone having such a streaming function has also been proposed. Normally, a stream image is transferred at a constant bit rate regardless of the state of the mobile terminal, and communication resources are occupied between the server and the mobile terminal during streaming.

  Therefore, a technique has been proposed in which the amount of moving image data transferred from the server is reduced by detecting the user's line-of-sight direction and lowering the resolution of the peripheral area compared to the image area the user is gazing at. (For example, Patent Documents 1 to 3). If this technology is applied to a mobile terminal, the amount of data transmission during streaming is suppressed, so that the processing load on the mobile terminal is reduced and power consumption during streaming can be suppressed.

  However, when the resolution of the image area around the gaze area in the line-of-sight direction is reduced, it is not easy to sufficiently follow the change in the line-of-sight direction. In particular, when the line-of-sight direction moves, it is necessary to instruct the streaming server to increase the resolution for a new gaze area, but there is a problem that a time lag occurs until the resolution of the gaze area actually increases. Patent Document 4 discloses a technique for detecting a point of gaze on a screen by specifying the position of an eyeball using blinking eyes.

JP-A-1-141479 JP 7-44110 A JP 2004-56335 A JP-A-10-154220

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an image display device capable of displaying a moving image in accordance with a user's line-of-sight direction. In particular, an image display device capable of suppressing a time lag until a moving image is switched from a low-load moving image to a high-load moving image when the line-of-sight direction moves from outside the display region to the display region is provided. It is aimed.

  In addition, the present invention can switch the image quality of a moving image by following the movement in the line of sight, and can erroneously switch from a low-load moving image to a high-load moving image when no moving image is viewed. An object of the present invention is to provide an image display device that can be suppressed. It is another object of the present invention to provide an image display device that can display a moving image acquired from a streaming server by following the movement of the user's line of sight.

  It is another object of the present invention to provide a computer program for causing a computer to function as such an image display device.

  An image display device according to a first aspect of the present invention is directed to display means for displaying a moving image in a display area, gaze direction detecting means for detecting a user's gaze direction, and gaze at the moving image based on the gaze direction. Gaze discrimination means for discriminating whether or not the eye is moving; gaze movement discrimination means for discriminating the movement direction of the gaze direction; and determining whether or not the movement direction is a direction from the outside of the display area toward the display area. Based on the determination results of the moving direction discriminating means and the gaze discriminating means, the display target is changed to a high-load moving image when the moving image is being watched, while the display target is displayed when the moving image is not being watched Even if the moving image is not gazed, the display object is moved from the low-load moving image to the high load when the line-of-sight direction moves toward the display area. Load video Constructed and a changing display image switching unit Ri.

  In this image display device, it is determined whether or not the moving image in the line-of-sight direction is directed from the outside of the display area to the display area by determining whether or not the user is gazing at the moving image. The When the line-of-sight direction moves toward the display area, the display target is switched from the low-load moving image to the high-load moving image. For this reason, when the line-of-sight direction moves from the outside of the display area to the inside of the display area, a time lag until the moving image is switched from the low-load moving image to the high-load moving image can be suppressed. In particular, switching to a high-load moving image can be performed before the line-of-sight direction reaches the display area. Therefore, an appropriate moving image can be displayed according to the user's line-of-sight direction.

  In addition to the above configuration, the image display device according to a second aspect of the present invention is configured such that the gaze determination unit determines gaze of the moving image based on whether or not the line-of-sight direction is in the display area. Composed. According to such a configuration, it is possible to switch between a high-load moving image and a low-load moving image depending on whether or not the line-of-sight direction is facing the display area.

  An image display device according to a third aspect of the present invention includes, in addition to the above configuration, peripheral vision determination means that determines whether or not the moving image is peripherally viewed based on the line-of-sight direction, and the display image switching means is In a state where the line-of-sight direction moves toward the display area in a state where the moving image is viewed in the vicinity, the display target is switched to the high-load moving image, and the moving image is not viewed in the periphery. Even if the line-of-sight direction moves toward the display area, the display target is not switched.

  In this image display device, if the moving image is not viewed from the periphery, the display target is not switched even if the line-of-sight direction moves toward the display area. For this reason, it is possible to prevent the display target from being switched from the low-load moving image to the high-load moving image even though the moving image is not viewed at all. Therefore, it is possible to switch the image quality of the moving image by following the movement in the line-of-sight direction, and to suppress erroneous switching to the high-load moving image when no moving image is viewed.

  According to a fourth aspect of the present invention, in addition to the above-described configuration, an eye position detection unit that detects a user's eye position, and whether the user is within a 3D viewing angle of the display screen based on the eye position. Viewing angle determining means for determining whether or not the display means displays either a 3D moving image or a 2D moving image in the display area, and the display image switching means is configured so that the user can display the 3D visual field. When the line-of-sight direction moves toward the display area while in the corner, the display target is switched from the 2D moving image to the 3D moving image, and when the user is outside the 3D viewing angle, Even if the line-of-sight direction moves toward the display area, the display target is not switched.

  In this image display device, if the user is not within the 3D viewing angle of the display screen, the display target is not switched even if the line-of-sight direction moves toward the display area. For this reason, it is possible to prevent the display target from being switched from the 2D moving image to the 3D moving image, even though the user is in a position where the 3D moving image cannot be viewed correctly. Accordingly, it is possible to switch the moving image by following the movement in the line-of-sight direction, and to suppress erroneous switching from the 2D moving image to the 3D moving image when the 3D moving image cannot be viewed correctly.

  An image display device according to a fifth aspect of the present invention includes, in addition to the above configuration, moving image data acquisition means for sequentially acquiring moving image data including a series of image frames from a streaming server on a communication network, and the display means includes: The moving image is displayed based on the moving image data, and the display image switching unit requests the high-load moving image data from the streaming server when the moving image is being watched. The low-load moving image data is requested when the user is not gazing, and the high load is applied when the line-of-sight direction moves toward the display area even when the gazing image is not gazed. It is configured to request switching to moving image data.

  According to such a configuration, since the switching to the high-load moving image is instructed to the streaming server before the line-of-sight direction reaches the display area, even the moving image acquired from the streaming server It can be displayed following the movement of the user's line of sight.

  In addition to the above-described configuration, the image display device according to the sixth aspect of the present invention includes moving image data acquisition means for sequentially acquiring the moving image data from a camera that shoots a subject and generates moving image data including a series of image frames. The display means displays the moving image based on the moving image data, and the display image switching means requests high-load moving image data when the moving image is being watched by the camera. On the other hand, when low-load moving image data is requested when the moving image is not watched, and the line-of-sight direction moves toward the display area even when the moving image is not watched Is configured to request switching to the high-load moving image data.

  According to such a configuration, the camera is instructed to switch to a high-load moving image before the line-of-sight direction reaches the display area. A moving image can be displayed.

  An image display device according to a seventh aspect of the present invention includes, in addition to the above configuration, a moving image data acquisition unit that acquires moving image data including a series of image frames from each of two or more surveillance cameras. The moving image is displayed based on the moving image data of the corresponding monitoring camera having the display area as described above, and the display image switching means is connected to the monitoring camera on which the moving image is being watched. While requesting high-load moving image data, while requesting low-load moving image data to the monitoring camera not watching the moving image, and not watching the moving image, The monitoring camera whose viewing direction has moved toward the display area is configured to request switching to the high-load moving image data.

  In this image display device, when the line-of-sight direction moves toward the display area, the monitoring camera displaying the moving image data in the display area has a high level before the line-of-sight direction reaches the display area. An instruction to switch to a loaded moving image is given. For this reason, it is possible to display the moving image of the surveillance camera by following the movement of the user's line of sight.

  An image display device according to an eighth aspect of the present invention includes, in addition to the above configuration, moving image data storage means for holding two or more moving image data each consisting of a series of image frames, and decoding means for decoding the moving image data. The display means has two or more display areas, and each of the moving images is displayed based on the decoded moving image data, and the display image switching means While requesting high-load moving image data for the display area where the moving image is being watched, requesting low-load moving image data for the display area where the moving image is not being watched, and watching the moving image Even if not, if the line-of-sight direction moves toward the display area, the moving image data to be displayed in the display area Configured to request the switching to the high-load video data.

  In this image display device, when the line-of-sight direction moves toward the display area, the decoding means is instructed to switch the moving image data to be displayed in the display area to the high-load moving image data. For this reason, it is possible to display a moving image by following the movement of the user's line of sight while displaying an appropriate moving image according to the user's line of sight.

  A computer program for an image display device according to a ninth aspect of the present invention is based on the display procedure for displaying a moving image in the display area, the gaze direction detection procedure for detecting the gaze direction of the user, and the moving image based on the gaze direction. A gaze determination procedure for determining whether or not an image is being watched; a gaze movement determination procedure for determining a movement direction in the gaze direction; and whether the movement direction is a direction from the outside of the display area toward the display area. Based on the moving direction determination procedure for determining whether or not the moving image is determined, the display target is a high-load moving image when the moving image is being observed, and the moving image is not being observed. Even when the display target is a low-load moving image and the moving image is not being watched, if the line-of-sight direction moves toward the display area, the display target is moved from the low-load moving image. Consisting of a display image switching procedure for switching the serial high load moving image.

  In the image display device according to the present invention, when the line-of-sight direction moves toward the display area, the display target is switched to the high-load moving image. Therefore, when the line-of-sight direction moves from outside the display area into the display area, the moving image Can suppress a time lag until the low load moving image is switched to the high load moving image. Therefore, a moving image can be displayed according to the user's line-of-sight direction.

  In the image display device according to the present invention, the moving image can be switched following the movement in the line of sight, and the low load moving image can be erroneously switched from the low load moving image when the moving image is not viewed at all. This can be suppressed. Furthermore, since the streaming server is instructed to switch to a high-load moving image before the line-of-sight direction reaches the display area, even a moving image acquired from the streaming server can be displayed in the direction of the user's line-of-sight. It can be displayed following the movement.

  Further, it is possible to provide a computer program for causing a computer to function as the image display device described above.

1 is a system diagram showing a configuration example of a moving picture streaming system 1 including an image display device according to Embodiment 1 of the present invention. FIG. 2 is a block diagram illustrating a configuration example of the mobile phone 11 in FIG. 1, illustrating an example of a functional configuration in the mobile phone 11. It is a figure showing the characteristics of human visual acuity, and shows a characteristic curve of visual acuity that peaks in the vicinity of the central fovea of the macula and rapidly decreases when leaving the fovea. 4 is an explanatory diagram schematically showing a positional relationship between a user's eye position and line-of-sight direction and a mobile phone 11; FIG. It is the figure which showed the relationship between the coordinate used in the mobile telephone 11 of FIG. 2, and a gaze direction. FIG. 3 is a diagram showing an example of a gaze determination area 4 for determining gaze of a moving image in the mobile phone 11 of FIG. 2. It is explanatory drawing which showed typically an example of the operation | movement at the time of the streaming in the mobile telephone 11 of FIG. 2, and the mode of the image quality switching of the stream image based on a gaze direction is shown. 3 is a flowchart showing an example of an operation during streaming in the mobile phone 11 of FIG. FIG. 5 is a block diagram showing an example of the configuration of an image display device according to Embodiment 2 of the present invention, in which an example of a functional configuration in the mobile phone 11 is shown. It is the figure which showed an example of the peripheral vision determination area | region 5 for discriminating the peripheral vision of a moving image in the mobile telephone 11 of FIG. It is explanatory drawing which showed typically an example of the operation | movement at the time of the streaming in the mobile telephone 11 of FIG. 10 is a flowchart illustrating an example of an operation during streaming in the mobile phone 11 of FIG. 9. FIG. 9 is a block diagram showing an example of the configuration of an image display device according to Embodiment 3 of the present invention, and shows an example of a functional configuration in the mobile phone 11. It is the system figure which showed one structural example of the monitoring system 101 containing the image display apparatus 102 by Embodiment 4 of this invention. FIG. 15 is a block diagram illustrating a configuration example of a controller 103 in the image display apparatus 102 of FIG. 14. It is the perspective view which showed one structural example of the image display apparatus by Embodiment 5 of this invention, and the 2 screen terminal 201 is shown as an example of an image display apparatus. FIG. 17 is a block diagram illustrating a configuration example of the two-screen terminal 201 in FIG. 16, illustrating an example of a functional configuration in the two-screen terminal 201. FIG. 10 is a block diagram showing a configuration example of an image display device according to a sixth embodiment of the present invention, and shows an example of a functional configuration in the mobile phone 11. It is the figure which showed the relationship between 3D viewing angle B of the display 111 and the position of a user's eyes in the mobile telephone 11 of FIG.

Embodiment 1 FIG.
<Video streaming system>
FIG. 1 is a system diagram showing a configuration example of a moving picture streaming system 1 including an image display device according to Embodiment 1 of the present invention, and shows a mobile phone 11 as an example of the image display device. The moving picture streaming system 1 is a moving picture reproduction system including a mobile phone 11, a base station 12, a communication network 13, and a streaming server 14, and moving image data is transferred from the streaming server 14 to the mobile phone 11 and displayed on a screen.

  The mobile phone 11 is a portable communication terminal, and an operation unit 110, a display 111, and a camera 112 are arranged on the front surface of a thin terminal casing that is long in the vertical direction. The display 111 is a display device having a rectangular display screen, and displays a moving image in a predetermined display area. The camera 112 is an imaging device that captures an image of the terminal operator itself as a subject in order to detect the user's line-of-sight direction, and generates subject image data that captures the face or upper body of the terminal operator. The camera 112 is equipped with a fisheye lens in order to photograph a subject in front of the display 111.

  The base station 12 is a mobile base station that communicates with the mobile phone 11 via a mobile communication network, and is connected to a communication network 13 such as the Internet. The streaming server 14 is a moving image providing device that provides a stream image via the communication network 13.

  The stream image is stored in advance in the moving image storage unit 15 as moving image data including a series of image frames 15 a and is transferred to the mobile phone 11 via the communication network 13 and the base station 12. The moving image storage unit 15 holds stream images compressed for transfer. Such a stream image may be a live video shot using an imaging device or a CG video created by computer graphics. The stream image is divided into predetermined moving image packets and sequentially transferred.

  In this moving image streaming system 1, the user's line-of-sight direction is detected based on the subject image data, and based on the detection result, it is determined whether or not the stream image being displayed is being watched to determine the quality of the stream image. Adjusted. The adjustment of the image quality is performed, for example, by controlling the compression rate when the streaming server 14 compresses the data of the stream image for transfer, and the high-resolution moving image and the low-resolution moving image having a lower image quality than the high-resolution moving image. The image quality can be switched between images.

  Specific examples of switching image quality include luminance frequency, color frequency, motion interpolation accuracy, pixel interpolation accuracy, frame rate, number of colors, number of quantization bits or number of pixels between high-resolution video and low-resolution video Make them different. Further, the presence or absence of image processing such as inter-frame interpolation, image quality correction, and frame rate acceleration may be made different between the high-resolution moving image and the low-resolution moving image.

<Mobile phone>
FIG. 2 is a block diagram illustrating a configuration example of the mobile phone 11 in FIG. 1, and illustrates an example of a functional configuration in the mobile phone 11. The mobile phone 11 includes a display 111, a camera 112, a cellular communication unit 113, a moving image data acquisition unit 114, a decoding unit 115, a gaze direction detection unit 116, a gaze determination unit 117, a gaze movement determination unit 118, and a movement direction determination unit 119. And a display image switching unit 120.

  The cellular communication unit 113 communicates with the base station 12 via the antenna 113a, and transmits and receives audio signals and the like with other communication devices connected to the mobile communication network. The moving image data acquisition unit 114 acquires a stream image from the streaming server 14 on the communication network 13 via the mobile communication network, and outputs the stream image to the decoding unit 115.

  The decoding unit 115 is a decoding processing unit that decompresses a stream image for display, and the stream image after data decompression is output to the display 111. Stream images are sequentially acquired as moving image packets, decoded, and displayed on the screen.

  The gaze direction detection unit 116 detects the user's gaze direction based on the subject image data from the camera 112 and outputs the detection result to the gaze determination unit 117. Various conventionally known methods can be used as a method for detecting the line-of-sight direction based on the subject image data. For example, the face direction of the operator is detected by determining the position and orientation of the operator's face through face recognition processing and further determining the position of the pupil on the eyeball.

  The gaze determination unit 117 determines whether or not the user is watching the stream image being displayed based on the gaze direction detected by the gaze direction detection unit 116. In general, the visual field includes a gaze region with high visual acuity formed in the line-of-sight direction, and a peripheral vision region that is formed so as to surround the gaze region and has a visual acuity lower than that of the gaze region.

  The gaze determination of the stream image is performed based on whether or not the line-of-sight direction is in the display area. That is, if a part or all of the gaze area in the line-of-sight direction is included in the display area of the stream image, it is determined that the stream image is being watched. On the other hand, when the gaze area is separated from the display area, it is determined that the stream image is not being watched.

  Based on the determination result of the gaze determination unit 117, the display image switching unit 120 requests the streaming server 14 to switch the image quality in order to switch the stream image to be displayed to the image quality according to the user's line-of-sight direction. Specifically, when a stream image is being watched, high-resolution moving image data is required to switch the display target from a low-resolution moving image to a high-resolution moving image. On the other hand, when the stream image is not watched, low resolution moving image data is required to switch the display target from the high resolution moving image to the low resolution moving image.

  The line-of-sight movement determination unit 118 determines the movement direction in the line-of-sight direction, and outputs the determination result to the movement direction determination unit 119. The determination of the moving direction is performed, for example, by obtaining a gaze point in the gaze direction detected at a certain time and a gaze direction in the gaze direction after a minute time has elapsed from that time.

  The movement direction determination unit 119 determines whether or not the movement direction in the line-of-sight direction is a direction from the outside of the display area of the stream image toward the display area. Specifically, the distance between the gazing point and the display area of the stream image is compared before and after the lapse of the minute time, and it is determined whether or not a straight line connecting the gazing points before and after the lapse of the minute time intersects the display area. Thus, it is determined whether or not the direction is toward the display area.

  The display image switching unit 120 displays the gaze direction from outside the display area of the stream image even when the stream image is not being watched in order to sufficiently follow the movement in the gaze direction and switch the image quality of the stream image. When moving toward the area, the streaming server 14 is requested to switch to high resolution moving image data.

<Visual characteristics>
FIG. 3 is a diagram showing the characteristics of human visual acuity, and shows a characteristic curve of visual acuity that peaks in the vicinity of the central fovea of the macular region and rapidly decreases when leaving the fovea. The human visual acuity reaches a maximum (maximum value b) in the vicinity of the macular fovea (position a) on the retina, and decreases rapidly as the distance from the fovea approaches the ear or nose.

  In other words, when staring at a point on the display surface, sufficient visual acuity is obtained only in a narrow area in the line of sight including the gazing point. descend. In the present specification, the narrow area is referred to as a gaze area, and an area outside the gaze area in the field of view is referred to as a peripheral vision area. Usually, the gaze area is composed of an area of about ± 5 ° with the line-of-sight direction as the center. In the peripheral vision region, there is only vague visual acuity, and the movement and brightness change of an object can be recognized, but the shape and color of the object cannot be identified.

<User eye position and line-of-sight direction>
FIG. 4 is an explanatory view schematically showing the positional relationship between the user's eye position and line-of-sight direction and the mobile phone 11. The position E (E _X , E _Y , E _Z ) of the user's eyes and the direction vector ρ indicating the line-of-sight direction can be expressed using an XYZ coordinate system based on the display 111 of the mobile phone 11.

  Specifically, it is expressed using a coordinate system in which the center of the display screen of the display 111 is the origin, the X axis is perpendicular to the display screen, the Y axis is horizontal in the horizontal direction, and the Z axis is vertical. be able to.

<Relationship between coordinates and line-of-sight direction>
FIG. 5 is a diagram showing the relationship between the coordinates used in the mobile phone 11 of FIG. 2 and the line-of-sight direction. (A) in the figure shows a coordinate system composed of XYZ coordinate axes set based on the display area 2 of the display 111. The display area 2 is a rectangular area in the display screen, and a stream image is displayed in the display area 2. In the coordinate system, the center of the display area 2 is the origin, and the X axis is arranged perpendicular to the display area 2.

Further, the horizontal direction of the display area 2 is taken as the Y axis, and the vertical direction is taken as the Z axis. Further, the display region 2, the length of the Y-axis direction is S _Y, the length in the Z-axis direction is S _Z. Using such a coordinate system, the eye position E (E _X , E _Y , E _Z ) is represented.

(B) in the figure shows the positional relationship between the direction vector ρ indicating the line-of-sight direction and each coordinate axis. The direction vector ρ = (α, β, γ) is a unit vector having a length of 1, and the angle formed by the orthogonal projection on the XY plane and the X axis is θ ₁ and is positive in a vertical plane perpendicular to the XY plane. If the angle formed by the projection is θ ₂ , α, β, and γ are expressed by the following equation (1).

If the angles θ ₁ and θ ₂ are determined based on the subject image, each component of the direction vector ρ can be obtained using the above equation (1).

<Display area and gaze determination area>
FIG. 6 is a diagram showing an example of a gaze determination area 4 for determining gaze of a moving image in the mobile phone 11 of FIG. Whether or not the stream image is being watched is determined by determining whether or not the gaze point in the gaze direction exists in the gaze determination area 4 or outside the gaze determination area 4.

  The gaze point is a point where the line of sight intersects with the YZ plane, and the image quality of an appropriate stream image depends on whether the gaze point exists in the gaze determination region 4 or outside the gaze determination region 4. Selected. In the present embodiment, in order to simplify the processing, the inside of the circle passing through the vertex 3 of the display area 2 is set as the gaze determination area 4 of the stream image. That is, whether the gazing point is within the display area 2 or outside the display area 2, whether the gazing point is within the gaze determination area 4 or outside the gaze determination area 4 is simplified. Determined.

  The gaze determination area 4 is an area in which a boundary line indicating the outer edge circumscribes the rectangular display area 2, and the boundary line is a circle whose center is the origin of the YZ plane and whose diameter is the diagonal line of the display area 2. is there.

In detail, the eye position _{E (E X, E Y,} E Z) and direction vector ρ = (α, β, γ ) with reference to, the position in the YZ plane of the gazing point, _{(E Y} - E _X × β / α, E _Z −E _X × γ / α).

Therefore, whether the gaze point is in the gaze determination area 4 or outside the gaze determination area 4 can be determined based on the following equation (2).

  That is, if the above equation (2) is satisfied, the gazing point is present in the gazing determination area 4, so that it is determined that the stream image is being gazed and a high-resolution moving image is selected. On the other hand, when the above formula (2) is not satisfied, the gazing point exists outside the gazing determination area 4, so that it is determined that the stream image is not being gazed and a low-resolution moving image is selected. However, when the line-of-sight direction moves from the gaze determination area 4 toward the gaze determination area 4, the operation mode is switched from the low resolution moving image to the high resolution moving image.

  Whether the line-of-sight direction has moved from outside the gaze determination area 4 toward the gaze determination area 4 is determined by comparing the distance between the gaze point and the gaze determination area 4 before and after the elapse of a minute time, This is performed based on the determination result as to whether or not a straight line connecting the gazing points before and after the elapse of time intersects the gaze determination area 4.

  In general, even when the gazing point is approaching the gaze determination area 4, the line-of-sight direction does not necessarily move into the gaze determination area 4 as it is. When the gazing point approaches the gazing determination region 4 and the moving direction of the gazing point is a direction toward the gazing determination region 4, the operation mode is switched to the high resolution moving image.

Here, sufficient X component E _X eye position E increases, the influence of the change in the position of the eyes on the movement of the gazing point is sufficiently small compared to the effect of changes in the viewing direction on the movement of the gazing point Ignore changes in eye position.

Accordingly, if the direction vector at the time when the minute time has passed is (α + dα, β + dβ, γ + dγ) with respect to the direction vector ρ = (α, β, γ) at a certain time, the gaze point after the minute time has passed is , (E _Y −E _X × (β + dβ) / (α + dα), E _Z −E _X × (γ + dγ) / (α + dα)).

Whether or not the gaze point has approached the gaze determination area 4 can be determined based on the following formula (3) in which the distance between the gaze point and the center of the gaze determination area 4 is compared before and after the lapse of a minute time.

  That is, if the above equation (3) is satisfied, it can be determined that the gaze point has approached the gaze determination area 4. On the other hand, when the above formula (3) is not satisfied, it can be determined that the gaze point is not approaching the gaze determination area 4.

  Whether or not the moving direction of the gazing point is the direction toward the gaze determination area 4 is determined by obtaining a straight line connecting the gazing points before and after the elapse of a minute time, and determining the distance between the straight line and the center of the gaze determination area 4 This can be determined by comparing with the radius of the region 4.

A straight line connecting the gazing points before and after the minute time can be expressed by the following equation (4).

If dα is sufficiently smaller than α and the above equation (4) is arranged and summarized, the following equation (5) is obtained.

Distance between the straight line and the center of the attention judgment region 4 of the equation (5) (origin) is the radius of the attention judgment region _{^{4 (S Y 2/4 +}} S Z 2/4) as long as ^1/2 or less, of the gazing point The moving direction is a direction toward the gaze determination area 4. Here, an example of simple determination using the circular gaze determination area 4 as to whether or not the stream image is being watched and whether or not the line-of-sight direction has moved toward the display area 2 will be described. As described above, when the rectangular display area 2 is directly used for determination, the determination can be performed in the same manner as when the gaze determination area 4 is used.

<Switching display image>
FIG. 7 is an explanatory diagram schematically showing an example of an operation at the time of streaming in the mobile phone 11 of FIG. 2, and shows switching of the image quality of the stream image based on the line-of-sight direction. (A) in the figure shows the display 111 when the user's eyes are on the X axis. (B) in the figure shows a stream image being displayed on the display 111 on the XZ plane including the eye position E (E _X , E _Y , E _Z ) based on the line-of-sight direction and the movement direction of the line-of-sight direction. The image quality is switched between the high-resolution moving image and the low-resolution moving image.

  If the user's line-of-sight direction is facing the display 111, that is, if the direction vector ρ = (α, β, γ) is within the high load area A1, it is determined that the user is watching the stream image, A high-resolution moving image is selected as a display target. The boundary of the high load area A1 corresponds to the outer edge of the display 111.

  On the other hand, if the line-of-sight direction is facing out of the display 111, that is, if the direction vector ρ = (α, β, γ) is within the low load area A2, it is determined that the user is not gazing at the stream image, A low resolution moving image is selected as a display target. The low load area A2 is formed adjacent to the high load area A1.

  When a low-resolution moving image is selected, if it is detected that the line-of-sight direction moves toward the display 111, it is determined that the stream image will eventually be watched, and the display target is changed from the low-resolution moving image to the high-resolution moving image. Switch to an image. However, if the line-of-sight direction does not move into the high load area A1 within a certain time after switching to the high resolution moving image, the operation mode returns to the low load moving image.

  When the X component α of the direction vector ρ is 0 or more (non-display area A3), it is determined that the user is not facing the terminal side, and the non-display mode for interrupting the stream image display process is selected. The The non-display area A3 has a boundary corresponding to the X component α = 0.

  Steps S101 to S111 in FIG. 8 are flowcharts showing an example of an operation during streaming in the mobile phone 11 in FIG. First, the line-of-sight direction detection unit 116 detects the line-of-sight direction of the user based on the subject image data captured by the camera 112 (step S101). At this time, if the X component α of the direction vector ρ is obtained from the angle of the line-of-sight direction and it is determined that the user is not looking at the terminal side based on the X component α, the non-display mode is selected (step S102, S111).

  Next, the gaze determination unit 117 calculates a gaze point based on the detected gaze direction (step S103), and determines whether or not the user is gazing at the displayed stream image (step S104).

  At this time, the display image switching unit 120 requests the streaming server 14 to switch the image quality in order to switch the display target to the image quality corresponding to the user's line-of-sight direction based on the determination result by the gaze determination unit 117. That is, if the stream image is being watched, the high-load moving image mode in which the high-resolution moving image is to be displayed is selected, and if the stream image is not being watched, the low-load moving image in which the low-resolution moving image is to be displayed. An image mode is selected.

  When the low-load moving image mode is selected, the line-of-sight movement determination unit 118 determines the line-of-sight movement direction (step S105), and the movement direction determination unit 119 determines the minute time based on the determination result of the line-of-sight movement direction. It is determined whether or not the gazing point has approached the gazing determination area 4 as a result of elapse of time (step S106). At this time, if the gazing point is not approaching the gazing determination area 4, the low-load moving image mode is maintained as it is (step S110).

  On the other hand, if the gaze point is approaching the gaze determination area 4, the gaze direction is further determined based on whether or not a straight line connecting the gaze points before and after the elapse of a minute time intersects the gaze determination area 4. It is determined whether or not it has moved toward (step S107). At this time, if the line-of-sight direction has not moved toward the gaze determination area 4, the low-load moving image mode is maintained as it is (step S110).

  On the other hand, if the line-of-sight direction is moving toward the gaze determination area 4, the display image switching unit 120 requests the streaming server 14 to switch from the low-load video mode to the high-load video mode (step) S108).

  That is, when a movement in the line-of-sight direction outside the gaze determination area 4 is detected in the high-load moving image mode, switching to the low-load moving image mode is requested. Further, when movement in the line-of-sight direction into the gaze determination area 4 is detected in the low-load moving image mode, switching to the high-load moving image mode is requested. On the other hand, in the low-load moving image mode, if movement in the line-of-sight direction into the non-display area A3 is detected, the operation mode is switched to the non-display mode.

  Further, in the non-display mode, if movement in the line-of-sight direction outside the non-display area A3 is detected, the operation mode is switched to the low-load moving image mode. The processing procedure from step S101 to step S108 is repeated until the streaming ends (step S109).

  According to the present embodiment, when the line-of-sight direction moves toward the display area 2, the display target is switched to the high-resolution moving image, so the line-of-sight direction has moved from outside the display area 2 into the display area 2. In this case, the time lag until the stream image is switched from the low resolution moving image to the high resolution moving image can be suppressed. In particular, since the streaming server 14 is instructed to switch to a high-resolution moving image before the line-of-sight direction reaches the display area 2, even if the stream image is acquired from the streaming server 14, the user's It is possible to display the image by sufficiently following the movement in the line-of-sight direction.

Embodiment 2. FIG.
In the first embodiment, the example in which the stream image is switched to the high-resolution moving image when the line-of-sight direction moves toward the display region 2 has been described. On the other hand, in the present embodiment, it is determined whether or not the stream image is viewed from the periphery, and when the line-of-sight direction moves toward the display area 2 in the peripheral view state, the stream image is switched to the high-resolution moving image. However, in a state where the peripheral view is not performed, a case will be described in which the line-of-sight direction does not switch to the high-resolution moving image even if the line-of-sight direction moves toward the display area 2.

  FIG. 9 is a block diagram showing a configuration example of the image display device according to the second embodiment of the present invention, and shows an example of a functional configuration in the mobile phone 11. This mobile phone 11 is different from the mobile phone 11 of FIG. 2 in that it includes a peripheral vision determination unit 121.

  In order to prevent the peripheral vision determination unit 121 from erroneously switching from the low resolution moving image to the high resolution moving image when the stream image is not viewed at all, based on the visual line direction detected by the visual line direction detection unit 116, It is determined whether or not the user is viewing the stream image being displayed.

  The discrimination of the peripheral vision of the stream image is performed based on whether or not the line-of-sight direction is in a predetermined peripheral vision determination area. That is, if a part or all of the gaze area in the line-of-sight direction is included in the peripheral vision determination area, it is determined that the stream image is viewed in the peripheral area. On the other hand, when the gaze area is separated from the peripheral vision determination area, it is determined that the stream image is not peripherally viewed.

  The display image switching unit 120 switches the display target from the low-load moving image to the high-load moving image when the line-of-sight direction moves toward the display area while viewing the stream image in the peripheral view. On the other hand, when the stream image is not viewed from the periphery, the display target is not switched even if the line-of-sight direction moves toward the display area.

<Peripheral vision determination area>
FIG. 10 is a diagram showing an example of a peripheral vision determination area 5 for determining peripheral vision of a moving image in the mobile phone 11 of FIG. Whether or not the stream image is peripherally viewed is determined by determining whether or not the gaze point in the line-of-sight direction exists in the peripheral vision determination area 5 or outside the peripheral vision determination area 5. .

  The peripheral vision determination region 5 is an annular region having a boundary line (circle) indicating the outer edge of the gaze determination region 4 as an inner edge, a radius larger than the boundary line, and a circle concentric with the boundary line as an outer edge. If the gazing point exists in the peripheral vision determination area 5, it is determined that the stream image is viewed peripherally. If the gazing point exists outside the peripheral vision determination area 5, it is determined that the stream image is not viewed peripherally. Is done.

  FIG. 11 is an explanatory view schematically showing an example of an operation during streaming in the mobile phone 11 of FIG. The peripheral vision determination area 5 is formed adjacent to the high load area A1 in the low load area A2.

  When the direction vector ρ indicating the line-of-sight direction is within the peripheral vision determination area 5, if the movement of the line-of-sight direction toward the high load area A1 is detected, the display target is switched to the high-resolution moving image. On the other hand, even if the direction vector ρ is within the low load area A2 and not within the peripheral vision determination area 5, the display target is detected even if it is detected that the line-of-sight direction moves toward the high load area A1. Do not switch.

  Steps S201 to S212 in FIG. 12 are flowcharts illustrating an example of an operation during streaming in the mobile phone 11 in FIG. The processing procedure from step S201 to step S207 is the same as the processing procedure from step S101 to step S107 in FIG.

  If the line-of-sight direction has not moved toward the gaze determination area 4 in step S207, the low-load moving image mode is maintained as it is (step S211). On the other hand, when the line-of-sight direction is moving toward the gaze determination region 4, the peripheral vision determination unit 121 determines whether the user is peripherally viewing the stream image being displayed based on the detected line-of-sight direction. A determination is made (step S208).

  At this time, if the stream image is viewed peripherally, the display image switching unit 120 requests the streaming server 14 to switch from the low-load moving image mode to the high-load moving image mode (step S209). On the other hand, if the stream image is not viewed from the periphery, the low-load moving image mode is maintained as it is (step S211). The processing procedure from step S201 to step S209 is repeated until the streaming ends (step S210).

  According to the present embodiment, if the stream image is not viewed from the periphery, the display target is not switched even if the line-of-sight direction moves toward the display area 2, so the stream image is not viewed at all. It is possible to prevent the display target from being switched from the low resolution moving image to the high resolution moving image.

Embodiment 3 FIG.
In the first embodiment, an example has been described in which, when a stream image is acquired from the streaming server 14 on the communication network 13 and displayed, the user's line-of-sight direction is detected and the image quality of the stream image is switched. On the other hand, in the present embodiment, a case will be described in which when moving image data is acquired from a camera and displayed, the user's line-of-sight direction is detected and the image quality of the moving image data is switched.

  FIG. 13 is a block diagram showing a configuration example of the image display device according to the third embodiment of the present invention, and shows an example of a functional configuration in the mobile phone 11. The mobile phone 11 is different from the mobile phone 11 of FIG. 2 in that a camera 131 is provided.

  The camera 131 is an imaging device that captures a subject and generates a subject image. When waiting for still image shooting or moving image shooting, moving image data including a series of image frames is generated. The camera 131 can adjust the image quality of the moving image data.

  The moving image data acquisition unit 114 sequentially acquires moving image data from the camera 131 and outputs it to the display 111. The display 111 is a display device that displays a subject image captured by the camera 131 in a finder, and displays a moving image in a display area based on the moving image data acquired by the moving image data acquisition unit 114.

  The display image switching unit 120 requests the high resolution moving image data from the camera 131 when the moving image is being watched. On the other hand, when the moving image is not watched, low resolution moving image data is required. Even when the moving image is not being watched, when the line-of-sight direction moves toward the display area, switching to high-resolution moving image data is required.

  According to the present embodiment, the camera 131 is instructed to switch to a high-resolution moving image before the line-of-sight direction reaches the display area 2, and thus sufficiently follows the movement of the user's line-of-sight direction. Thus, the moving image of the camera 131 can be displayed.

  Note that when the camera 131 has an autofocus function that automatically focuses on the subject or an illumination function that illuminates the subject, the autofocus depends on whether or not the moving image of the camera 131 is being watched during standby for shooting. The function may be turned on or off, or the lighting may be different.

Embodiment 4 FIG.
In the first embodiment, an example has been described in which, when a stream image is acquired from the streaming server 14 on the communication network 13 and displayed, the user's line-of-sight direction is detected and the image quality of the stream image is switched. In contrast, in the present embodiment, a case will be described in which when moving image data is acquired from a plurality of monitoring cameras and displayed for each monitoring camera, the user's line-of-sight direction is detected and the image quality of the moving image data is switched. .

<Monitoring system>
FIG. 14 is a system diagram showing a configuration example of the monitoring system 101 including the image display apparatus 102 according to the fourth embodiment of the present invention. The monitoring system 101 is a moving image reproduction system including an image display device 102, a communication network 104, and a plurality of monitoring cameras 105, and moving image data captured by each monitoring camera 105 is transferred to the image display device 102, and each screen is displayed. Is displayed.

  The monitoring camera 105 is a monitoring imaging device connected to a communication network 104 such as a LAN (local area network), and generates moving image data including a series of image frames. The moving image data captured by the monitoring camera 105 can be adjusted in its image quality and is recorded in a storage device in the monitoring camera 105.

  The image display device 102 includes a plurality of displays 111 and a controller 103, and displays a moving image of the corresponding monitoring camera 105, respectively. At that time, based on the line-of-sight direction, it is detected which display 111 the user is gazing at, and the high-resolution moving image data is requested to the monitoring camera 105 on which the moving image is being watched. Low resolution moving image data is required for the surveillance camera 105 not being watched.

  FIG. 15 is a block diagram illustrating a configuration example of the controller 103 in the image display apparatus 102 of FIG. The controller 103 is different from the mobile phone 11 of FIG. 2 in that it includes a network I / F 141 and a display control unit 142.

  A network I / F (interface) 141 is a communication unit that communicates with each monitoring camera 105 via the communication network 104. The moving image data acquisition unit 114 acquires moving image data from each of the monitoring cameras 105 via the network I / F 141 and outputs the moving image data to the display control unit 142. The display control unit 142 is a screen data generation unit that generates screen data for displaying the monitoring video captured by the monitoring camera 105 and outputs the screen data to each display 111. A moving image is displayed on each display 111 based on the moving image data acquired from the corresponding monitoring camera 105.

  For example, the moving image data of “surveillance camera 1” is displayed on “display 1”, the moving image data of “monitoring camera 2” is displayed on “display 2”, and the moving image data of “monitoring camera 3” is , Displayed on “Display 3”.

  The display image switching unit 120 requests high resolution moving image data from the monitoring camera 105 in which the moving image is being watched, while requesting low resolution moving image data from the monitoring camera 105 in which the moving image is not being watched. To do. Even if the moving image is not being watched, the monitoring camera 105 whose line-of-sight direction has moved toward the display area is requested to switch to high-resolution moving image data.

  According to the present embodiment, when the line-of-sight direction moves toward the display area, the line-of-sight direction reaches the display area before the monitoring camera 105 displaying the moving image data in the display area. In addition, switching to a high-resolution moving image is instructed. For this reason, the moving image of the monitoring camera 105 can be displayed sufficiently following the movement of the user's line of sight.

Embodiment 5 FIG.
In the first embodiment, an example has been described in which, when a stream image is acquired from the streaming server 14 on the communication network 13 and displayed, the user's line-of-sight direction is detected and the image quality of the stream image is switched. In contrast, in the present embodiment, a case will be described in which when the moving image data in the storage device is decoded and displayed, the user's line-of-sight direction is detected and the image quality of the moving image data is switched.

<Two-screen terminal>
FIG. 16 is a perspective view showing a configuration example of an image display apparatus according to Embodiment 5 of the present invention, and a two-screen terminal 201 is shown as an example of the image display apparatus. The two-screen terminal 201 is a portable terminal that includes an operation unit 110, two displays 111, and a camera 112. Each display 111 is arranged to be separated from each other.

  The two-screen terminal 201 detects which display 111 the user is gazing at based on the line-of-sight direction when displaying a moving image on each display 111, and While the image quality is set to a high resolution, the image quality of a moving image that is not being watched is reduced to a low resolution.

  FIG. 17 is a block diagram illustrating a configuration example of the two-screen terminal 201 in FIG. 16, and an example of a functional configuration in the two-screen terminal 201 is illustrated. The two-screen terminal 201 is different from the mobile phone 11 of FIG. 2 in that it includes a moving image data storage unit 151.

  The moving image data storage unit 151 holds two moving image data 151a and 151b. The moving image data 151a and 151b are composed of a series of image frames, and are previously compressed for storage.

  The decoding unit 115 is a decoding processing unit that decompresses the moving image data 151a and 151b in the moving image data storage unit 151 for display, and adjusts the image quality of the moving image data 151a and 151b by adjusting the decoding amount. can do. The moving image data after data expansion is output to the corresponding display 111.

  Each display 111 displays a moving image in a display area based on the decoded moving image data. For example, the decoded moving image data “moving image 1” is displayed on “display 1”, and the decoded moving image data “moving image 2” is displayed on “display 2”.

  The display image switching unit 120 requests the decoding unit 115 for high-resolution moving image data for the display 111 on which the moving image is being watched, while requesting low-resolution moving image data for the display 111 on which the moving image is not being watched. To do. Even when the moving image is not being watched, if the line-of-sight direction moves toward the display area, the moving image data to be displayed in the display area needs to be switched to high-resolution moving image data. Is done.

  According to the present embodiment, when the line-of-sight direction moves toward the display area, the decoding unit 115 is instructed to switch the moving image data displayed in the display area to high-resolution moving image data. For this reason, it is possible to display a moving image sufficiently following the movement of the user's line of sight while displaying an appropriate moving image according to the user's line of sight.

Embodiment 6 FIG.
In the first embodiment, an example has been described in which, when a stream image is acquired from the streaming server 14 on the communication network 13 and displayed, the user's line-of-sight direction is detected and the image quality of the stream image is switched. In contrast, in the present embodiment, the position of the user's eyes is detected, it is determined whether the user is within the 3D viewing angle of the display 111, and the stream image is switched between the 3D moving image and the 2D moving image. Will be described.

  FIG. 18 is a block diagram showing a configuration example of the image display apparatus according to the sixth embodiment of the present invention, and shows an example of a functional configuration in the mobile phone 11. This mobile phone 11 is different from the mobile phone 11 of FIG. 2 in that an eye position detection unit 161 and a viewing angle determination unit 162 are provided.

The eye position detection unit 161 detects the user's eye position E (E _X , E _Y , E _Z ) based on the subject image data from the camera 112, and outputs the detection result to the viewing angle determination unit 162. . The viewing angle determination unit 162 determines whether the user is within the 3D viewing angle of the display 111 based on the eye position E detected by the eye position detection unit 161, and displays the determination result as the display image switching unit 120. Output to.

  The 3D viewing angle is a physical quantity indicating a range in which a 3D moving image (3D video) can be correctly viewed (stereoscopically) when the 3D moving image (3D video) is displayed on the display screen of the display 111. Is defined by the angle with respect to a straight line perpendicular to.

  The display 111 displays either the 3D moving image or the 2D moving image in the display area 2. The display image switching unit 120 switches the display target from the 2D moving image to the 3D moving image when the line-of-sight direction moves toward the display area 2 while the user is within the 3D viewing angle. On the other hand, when the user is outside the 3D viewing angle, the display target is not switched even if the line-of-sight direction moves toward the display area 2.

<3D viewing angle>
FIG. 19 is a diagram showing the relationship between the 3D viewing angle B of the display 111 and the position of the user's eyes in the mobile phone 11 of FIG. When a 3D moving image is displayed on the display 111, the 3D moving image can be correctly stereoscopically viewed within the 3D viewing angle B of the display 111. This 3D viewing angle B is defined by an angle with respect to a straight line (X axis) perpendicular to the display 111 through the center of the display 111, and is usually narrower than the viewing angle in the case of displaying a 2D moving image.

  When the user's eye position E is within such a 3D viewing angle B, if the line-of-sight direction moves toward the display area 2, the display target is switched from the 2D moving image to the 3D moving image. On the other hand, when the eye position E is outside the 3D viewing angle B, the display target is not switched even if the line-of-sight direction moves toward the display area 2.

  According to the present embodiment, if the user is not within the 3D viewing angle B of the display 111, the display target is not switched even if the line-of-sight direction moves toward the display area. For this reason, it is possible to prevent the display target from being switched from the 2D moving image to the 3D moving image even though the user is in a position where the 3D moving image cannot be viewed correctly. Accordingly, it is possible to switch the image quality of the moving image sufficiently following the movement in the line of sight, and to prevent the 3D moving image from being erroneously switched from the 2D moving image to the 3D moving image when the 3D moving image cannot be visually recognized correctly. it can.

  In the first to sixth embodiments, an example in which a subject is photographed using the camera 112 and the user's gaze direction is detected by analyzing the image data has been described. However, the gaze direction detection method is described below. It is not limited to this. For example, the present invention also includes a method for detecting the direction of the line of sight using a method for measuring the steady potential of the eyeball to identify the position of the eyeball, or a method for detecting a reflection image by the cornea with a position detection sensor.

  In the first to sixth embodiments, the example in which the user's line-of-sight direction is detected and the moving image quality is switched has been described. However, even if the touch panel is switched between enabled and disabled in conjunction with the moving image quality switching. good. For example, when the display 111 is a touch panel display device that detects a user operation, the image quality of a moving image is switched between a high-load moving image and a low-load moving image depending on whether or not the moving image is being watched. The present invention includes those that switch between enabling and disabling the touch panel in conjunction with the above.

DESCRIPTION OF SYMBOLS 1 Video streaming system 2 Display area 3 Vertex 4 Gaze determination area 5 Peripheral vision determination area 11 Mobile phone 110 Operation part 111 Display 112 Camera 113 Cellular communication part 113a Antenna 114 Moving image data acquisition part 115 Decoding part 116 Gaze direction detection part 117 Discriminating unit 118 Line-of-sight movement discriminating unit 119 Moving direction discriminating unit 120 Display image switching unit 121 Peripheral vision discriminating unit 12 Base station 13 Communication network 14 Streaming server 15 Moving image storage unit 15a Image frame 101 Monitoring system 102 Image display device 103 Controller 104 Communication Network 105 Surveillance camera 131 Camera 141 Network I / F
142 display control unit 151 moving image data storage unit 161 eye position detection unit 162 viewing angle determination unit 201 2-screen terminal A1 high load region A2 low load region A3 non-display region B 3D viewing angle

Claims (9)

Display means for displaying a moving image in the display area;
Gaze direction detection means for detecting the gaze direction of the user;
Gaze determining means for determining whether or not the moving image is being watched based on the line-of-sight direction;
Eye movement determination means for determining the movement direction of the eye movement direction;
A moving direction determining means for determining whether or not the moving direction is a direction from the outside of the display area toward the display area;
Based on the determination result of the gaze determination unit, the display target is changed to a high-load moving image when the moving image is being watched, while the display target is changed to a low-load moving image when the moving image is not being watched. In addition, even when the moving image is not watched, if the line-of-sight direction moves toward the display area, the display target is switched from the low-load moving image to the high-load moving image. An image display device comprising image switching means.   The image display apparatus according to claim 1, wherein the gaze determination unit determines gaze of the moving image based on whether or not the line-of-sight direction is in the display area. Peripheral vision discriminating means for discriminating whether or not the moving image is viewed peripherally based on the line-of-sight direction,
The display image switching means switches the display target to the high-load moving image when the line-of-sight direction moves toward the display area in a state where the moving image is viewed in the periphery, and the moving image is viewed in the peripheral view. 3. The image display device according to claim 1, wherein the display target is not switched even when the line-of-sight direction moves toward the display area in a state in which the display is not performed. Eye position detecting means for detecting the position of the user's eyes;
Viewing angle determination means for determining whether the user is within the 3D viewing angle of the display screen based on the position of the eyes,
The display means displays either a 3D moving image or a 2D moving image in the display area,
The display image switching means switches the display target from the 2D moving image to the 3D moving image when the line-of-sight direction moves toward the display area while the user is within the 3D viewing angle. 3. The image display device according to claim 1, wherein when the user is outside the 3D viewing angle, the display target is not switched even if the line-of-sight direction moves toward the display area. Moving image data acquisition means for sequentially acquiring moving image data consisting of a series of image frames from a streaming server on a communication network;
The display means displays the moving image based on the moving image data,
The display image switching means requests the high-load moving image data to the streaming server when the moving image is being watched, and requests low-load moving image data when the moving image is not being looked at. In addition, even when the moving image is not watched, when the line-of-sight direction moves toward the display area, the switching to the high-load moving image data is requested. The image display device according to claim 1. A moving image data acquisition unit that sequentially acquires the moving image data from a camera that shoots a subject and generates moving image data including a series of image frames;
The display means displays the moving image based on the moving image data,
The display image switching means requests high-load moving image data when the moving image is being watched from the camera, and requests low-load moving image data when the moving image is not being looked at. In addition, even when the moving image is not being watched, when the line-of-sight direction moves toward the display area, switching to the high-load moving image data is requested. Item 5. The image display device according to any one of Items 1 to 4. Moving image data acquisition means for acquiring moving image data consisting of a series of image frames from each of two or more surveillance cameras;
The display means has two or more display areas, and displays the moving images based on the moving image data of the corresponding monitoring cameras,
The display image switching means requests high-load moving image data from the monitoring camera on which the moving image is being watched, while low-load moving image data is requested from the monitoring camera on which the moving image is not being watched. And even if the moving image is not watched, the monitoring camera whose viewing direction has moved toward the display area is requested to switch to the high-load moving image data. The image display device according to claim 1, wherein: Moving image data storage means for holding two or more moving image data each consisting of a series of image frames;
Decoding means for decoding the moving image data,
The display means has two or more display areas, and displays the moving images based on the decoded moving image data,
The display image switching means requests the high-load moving image data for the display area where the moving image is being watched from the decoding means, while the low-load moving image is used for the display area where the moving image is not being watched. Even when the image data is requested and the moving image is not being watched, the moving image data to be displayed in the display area when the line-of-sight direction moves toward the display area. 5. The image display device according to claim 1, wherein switching to high-load moving image data is requested. A computer program for an image display device,
A display procedure for displaying a moving image in the display area;
Gaze direction detection procedure for detecting the gaze direction of the user;
Gaze determination procedure for determining whether or not the moving image is being watched based on the line-of-sight direction;
A line-of-sight movement determination procedure for determining a movement direction of the line-of-sight direction;
A moving direction determination procedure for determining whether or not the moving direction is a direction from the outside of the display area toward the display area;
Based on the gaze determination result, the display target is a high-load moving image when the moving image is being watched, and the display target is a low-load moving image when the moving image is not being watched. Even when the moving image is not watched, when the line-of-sight direction moves toward the display area, the display image switching is performed to switch the display target from the low-load moving image to the high-load moving image. A computer program characterized by comprising a procedure.

Images