JP6688367B1 - Video distribution device, terminal, video distribution system, video distribution method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deliver a high quality area according to a user's visual field range in a panoramic video. A video distribution device connected to a terminal for playing a panoramic video through a network, the frame image of the panoramic video including the range depending on the position of the range displayed on the terminal, Further, any one of the first high-quality image data of a predetermined image size and the second high-quality image data including the range and including the vicinity of the pole when represented by the omnidirectional projection sphere is described. Determining means for determining whether to deliver to the terminal, and the first high image quality data or the second high image quality data, and a low level obtained by compressing the frame image to the image size according to the determination result by the determining means. And a delivery unit configured to deliver the image quality data and the first image quality data or the second image quality data produced by the creation unit and the low image quality data to the terminal. The features. [Selection diagram] Fig. 4

Description

  The present invention relates to a moving picture distribution device, a terminal, a moving picture distribution system, a moving picture distribution method, and a program.

  2. Description of the Related Art In recent years, a camera device capable of shooting a 360-degree moving image in all directions is known, and a moving image shot by such a camera device is a panoramic moving image (or "panoramic image" or "360-degree panoramic moving image"). Also referred to as)) is available for viewing.

  In addition, for example, the moving image distribution server performs streaming distribution of a panoramic moving image to a terminal so that the terminal can view the panoramic moving image. However, the panoramic video generally has a large data size, and it takes time to deliver the panoramic video, and it may take time before the panoramic video is displayed on the terminal.

  On the other hand, a technology is known in which a range displayed on a terminal (hereinafter, also referred to as a “field of view range”) is distributed with normal image quality, and a range not displayed on the terminal is distributed with low image quality (Non-patent Reference). Reference 1).

  For example, as shown in FIG. 1, in a panoramic video image represented by a omnidirectional projection sphere, the center of the omnidirectional projection sphere is set as an observation position, and a pseudo camera device at this observation position has a predetermined angle of view. The captured range is the field of view. Further, the panoramic video represented by the omnidirectional projection sphere can be represented by an equirectangular projection with a vertical angle θ of 0 to π and a horizontal angle φ of 0 to 2π. At this time, in the technique described in Non-Patent Document 1, partial area data including the visual field range of the panoramic video represented by the equirectangular projection is “partial area tile”, and data obtained by compressing the entire panoramic video is “entire”. Delivered to terminals as "reduced tiles". By using this technology, it is possible to reduce the time required to distribute a panoramic video, and it is possible to view high-quality video in the visual field range and even if the visual field range is moved It can be viewed without interruption. In this specification, compression means reduction in image size.

Daisuke Ochi, Shinnosuke Iwaki, "Real-time spherical image distribution system (Special feature Dwango x NTT R & D collaboration)", NTT Technical Journal 27 (4), 51-54, 2015-04

  However, in the technique described in Non-Patent Document 1, an area corresponding to the partial area tile on the omnidirectional projection sphere (hereinafter, the area on the omnidirectional projection sphere is referred to as “effective” depending on the vertical angle θ of the partial area tile). Also referred to as "area") may be smaller. For example, as shown in FIG. 2, when the vertical angle θ of the upper side of the partial area tile is π, the effective area of the partial area tile has three vertices in which one vertex is the north pole on the spherical surface of the omnidirectional projection sphere. It becomes a picture-shaped area.

  For this reason, for example, as shown in FIG. 2, when the visual field range is moved toward the North Pole, the effective area corresponding to the partial area tile becomes smaller than the visual field range, and high-quality moving images cannot be viewed in the visual field range. There were cases.

  The embodiment of the present invention has been made in view of the above points, and an object thereof is to distribute a high image quality region according to a visual field range of a user in a panoramic video.

  In order to achieve the above object, an embodiment of the present invention is a moving image distribution apparatus connected to a terminal for playing a panoramic moving image via a network, in which a frame image of the panoramic moving image is displayed on the terminal. Depending on the position of the first range, the first high-quality image data of a predetermined image size, and the second range including the range and including the vicinity of the pole when represented by the omnidirectional projection sphere. Determining means for determining which of the high image quality data to be delivered to the terminal, and the first high image quality data or the second high image quality data according to the determination result by the determining means. Creating means for creating the low image quality data obtained by compressing the frame image to the image size; and the first high image quality data or the second high image quality data and the low image quality data created by the creating means. end It characterized by having a a delivery means for delivering the.

  It is possible to distribute a high quality area in the panoramic video according to the user's visual field range.

It is a figure for demonstrating an example of a prior art. It is a figure for explaining a subject. It is a figure showing an example of the whole composition of the panoramic video distribution system concerning this embodiment. It is a figure for explaining an example of a zenith tile. It is a figure showing an example of functional composition of a panoramic video distribution system concerning this embodiment. It is a sequence diagram which shows an example of the panoramic video distribution process concerning this embodiment.

  Hereinafter, embodiments of the present invention (hereinafter, also referred to as “this embodiment”) will be described in detail with reference to the drawings. In the present embodiment, a partial area tile or a tile that covers the vicinity of the pole of the omnidirectional projection sphere (the value of the vertical angle θ) in the panoramic video represented by the equirectangular projection is used ( A panoramic video distribution system 1 that distributes any of the below-mentioned zenith tiles) will be described.

  Here, it is assumed that the partial area tile and the zenith tile have higher image quality than the overall reduced tile. Therefore, the partial area tiles and the zenith tiles are also referred to as “high image quality tiles”, and the entire reduced tiles are also referred to as “low image quality tiles”. A tile is a rectangular area in a panoramic video represented by the equirectangular projection. However, the tile does not necessarily have to be rectangular, and may be a region having any shape such as a triangle or a circle.

  The panoramic video is a video in which a frame image is an image represented by a omnidirectional projection sphere (or an image represented by the equirectangular cylindrical projection method). In this embodiment, it is assumed that each frame image of the panoramic video is represented by the equirectangular projection. In this case, the panoramic video is represented by the omnidirectional projection sphere by mapping the frame image represented by the equirectangular cylinder projection as a texture on the omnidirectional projection sphere at the time of rendering during viewing.

  Note that the panoramic video may or may not include audio. The panoramic video is supposed to be a live-action image, but the panoramic video is not necessarily a live-action image, and may be, for example, CG (computer graphics) or animation.

<Overall structure>
First, the overall configuration of the panoramic video distribution system 1 according to the present embodiment will be described with reference to FIG. FIG. 3 is a diagram showing an example of the overall configuration of the panoramic video distribution system 1 according to the present embodiment.

  As shown in FIG. 3, the panoramic video distribution system 1 according to the present embodiment includes a panoramic video distribution server 10 and one or more terminals 20. Further, the panoramic video distribution server 10 and the terminal 20 are communicably connected via a network N such as the Internet.

  The panoramic video distribution server 10 is a computer or a computer system that streams and distributes a panoramic video in response to a request from the terminal 20. At this time, the panoramic video distribution server 10 sets a partial area tile or a zenith tile, which will be described later, and an overall reduction tile according to the position (the value of the vertical angle θ) of the visual field range displayed on the terminal 20. To deliver to. In the present embodiment, the range displayed on the terminal 20 in the panoramic video is referred to as a “viewing range”. The viewing range is referred to as, for example, a “viewing range”, a “display range”, or a “viewing range”. May be done.

  Here, the partial area tile is data of a partial area including a visual field range in a panoramic video (more accurately, a frame image of the panoramic video). As will be described later, the zenith tile is an effective area that includes the field of view in the panoramic video (more accurately, the frame image of the panoramic video) and that corresponds to the zenith tile in the omnidirectional projection sphere. It is a partial area that includes the vicinity of the pole (that is, the vicinity of the pole). Further, the overall reduced tile is data obtained by compressing the entire panoramic video (more accurately, the frame image of the panoramic video).

  The terminal 20 is a smartphone, a tablet terminal, a head mounted display, a wearable device, a PC (personal computer), or the like that can view a panoramic video. The user can view the panoramic video distributed from the panoramic video distribution server 10 using the terminal 20.

  Here, the user can move or change the visual field range in the panoramic video by operating the terminal 20 or the like. Such an operation may be, for example, a swipe operation or a flick operation on the display of the terminal 20, an operation of pressing a moving button in the visual field range, or a moving button in the visual field range using a pointing device such as a mouse. It may be a pressing operation or the like. In addition, when the terminal 20 is provided with a sensor capable of detecting 360 ° orientations in all directions (up, down, left and right), it is possible to move or change the visual field range by changing the orientation of the terminal 20. Is also good.

  The configuration of the panoramic video distribution system 1 shown in FIG. 1 is an example, and other configurations may be used. For example, when a panoramic video is live-distributed to the terminal 20, the panoramic video distribution system 1 includes a camera device capable of shooting a 360-degree video in all directions and a microphone for collecting sound. Is also good. Further, for example, when a panoramic video is distributed on demand to the terminal 20, a storage device or the like that holds the panoramic video may be included in the panoramic video distribution system 1.

<Zenith tile>
Next, the zenith tile will be described with reference to FIG. FIG. 4 is a diagram for explaining an example of the zenith tile. Hereinafter, the position of the visual field range is represented by the center coordinates of the visual field range. The center coordinates are represented by a set (φ, θ) of horizontal angle φ and vertical angle θ.

As shown in FIG. 4A, when the vertical angle θ of the central coordinates of the visual field range is close to π (in other words, when the vertical angle θ of the central coordinates is the first threshold Th ₁ or more), the panoramic video distribution server 10 includes the field of view, and four vertices (0, π), (0 , θ 1), with _{(2π, θ 1), (} 2π, π) zenith tiles represented by (hereinafter, this The zenith tile is also referred to as a “first zenith tile”. The effective area of this first zenith tile includes the vicinity of the North Pole.

Here, θ ₁ is a parameter for determining the height (width in the vertical angle direction) of the first zenith tile. This θ ₁ may be a predetermined value or may be set by the user. Since the field of view needs to be included in the first zenith tile, it is necessary to [pi-theta ₁ the height of the field of view is so theta ₁ is larger than the (vertical angular width) is determined. Further, for the same reason, the first threshold Th ₁ is determined according to θ ₁ . For example, when ε ₁ is a parameter and the height of the visual field range is h, the first threshold value Th ₁ = θ ₁ + h × 1/2 + ε ₁ is determined.

As shown in FIG. 4B, when the vertical angle θ of the center coordinates of the visual field range is close to 0 (in other words, when the vertical angle θ of the center coordinates is the second threshold Th ₂ or less), the panoramic video distribution server 10 is the zenith tile (hereinafter, this zenith tile is included in the visual field range and whose four vertices are represented by (0, θ ₂ ), (0, 0), (2π, 0), (2π, θ ₂ ). The zenith tile is also referred to as a "second zenith tile". The effective area of this second zenith tile includes the vicinity of the South Pole.

Here, θ ₂ is a parameter for determining the height of the second zenith tile. This θ ₂ may be a predetermined value or may be set by the user. Note that since the visual field range needs to be included in the second zenith tile, θ ₂ needs to be determined so that θ ₂ is larger than the height of the visual field range. Further, for the same reason, the second threshold Th ₂ is determined according to θ ₂ . For example, when ε ₂ is a parameter and the height of the visual field range is h, it is determined that the second threshold value Th ₂ = θ ₂ −h × 1 / 2−ε ₂ or the like.

Regarding the relationship between the parameters θ ₁ and θ ₂ described above, π−θ ₁ ≠ θ ₂ may be satisfied, or π−θ ₁ = θ ₂ may be satisfied. When π−θ ₁ ≠ θ ₂ , the height of the first zenith tile and the height of the second zenith tile are different, while when π−θ ₁ = θ ₂ , the height of the first zenith tile is And the height of the second zenith tile are the same.

  As described above, the panoramic video distribution server 10 according to the present embodiment performs partial processing when the position of the visual field range is close to the vertical angle θ = π or when the position of the visual field range is close to the vertical angle θ = 0. The zenith tile is delivered to the terminal 20 instead of the area tile. As a result, the effective area of the omnidirectional projection sphere can be increased.

  In the above description, the zenith tile is distributed to the terminal 20 when the position of the field of view is close to the vertical angle θ = π or when the position of the field of view is close to the vertical angle θ = 0. In addition to this, for example, after predicting that the position of the visual field range is close to the vertical angle θ = π or θ = 0 using the history of the visual field range of the user (history of the center coordinates of the visual field range) or the like, The zenith tile may be delivered to the terminal 20 according to the prediction result.

  In the panoramic video represented by the equirectangular projection, the amount of information per predetermined unit area decreases as it approaches the pole (that is, as the vertical angle θ moves away from π / 2). Therefore, the zenith tile can be distributed with a data size comparable to that of the partial area tile.

<Functional configuration>
Next, the functional configuration of the panoramic video distribution system 1 according to the present embodiment will be described with reference to FIG. FIG. 5 is a diagram showing an example of the functional configuration of the panoramic video distribution system 1 according to the present embodiment.

  As shown in FIG. 5, the panoramic video distribution server 10 of the panoramic video distribution system 1 according to the present embodiment has a video distribution processing unit 101 as a functional unit. The functional unit is realized by a process that is executed by a CPU (Central Processing Unit) or the like by one or more programs installed in the panoramic video distribution server 10.

  In response to a request from the terminal 20, the moving image distribution processing unit 101 executes a process of distributing a panoramic moving image (that is, a partial area tile or a zenith tile and an entire reduced tile of each frame image of the panoramic moving image) to the terminal 20. . Here, the moving image delivery processing unit 101 includes a determination unit 111, a tile creation unit 112, and a delivery unit 113.

The determination unit 111 determines whether to deliver a partial area tile or a zenith tile as the high quality tile. Here, the determination unit 111 compares the vertical angle θ of the center coordinates of the visual field range with a predetermined threshold value (first threshold value Th ₁ and second threshold value Th ₂ ) to determine the partial area tile or the zenith. Determine which of the tiles to deliver.

  The tile creating unit 112 creates a high quality tile and a low quality tile according to the determination result of the determining unit 111. That is, the tile creating unit 112 creates the partial region tile and the entire reduced tile when the determining unit 111 determines that the partial region tile is to be delivered as the high quality tile. On the other hand, when the determination unit 111 determines that the zenith tile is to be delivered as the high quality tile, the tile creation unit 112 creates the zenith tile and the entire reduced tile.

  Note that, for example, when a panoramic video is live-distributed to the terminal 20, the tile creating unit 112 creates a high quality tile and a low quality tile using the panoramic video received from the camera device or the like. On the other hand, for example, when a panoramic video is delivered to the terminal 20 on demand, the tile creating unit 112 uses the panoramic video stored in advance in a predetermined storage device or the like to generate high-quality tiles and low-quality images. Create tiles and.

  The distribution unit 113 distributes the high image quality tile and the low image quality tile created by the tile creation unit 112 to the terminal 20.

  Further, as shown in FIG. 5, the terminal 20 of the panoramic video distribution system 1 according to the present embodiment has a video viewing processing unit 201 as a functional unit. The functional unit is realized by a process that the CPU executes by one or more programs installed in the terminal 20.

  The video viewing processing unit 201 transmits a tile distribution request for displaying a panoramic video to the panoramic video distribution server 10. Here, the tile distribution request includes, for example, the center coordinates of the visual field range or information for specifying the center coordinates. The information for specifying the center coordinates of the visual field range includes, for example, the coordinates of each vertex of the visual field range.

  Further, the moving image viewing processing unit 201 displays the panoramic moving image by the tiles (high quality tile and low quality tile) distributed from the panoramic video distribution server 10. As a result, the panoramic video distributed by streaming from the panoramic video distribution server 10 is displayed on the terminal 20.

<Panorama video distribution processing>
Next, a process (panoramic video distribution process) in which the panoramic video distribution server 10 distributes a panoramic video to the terminal 20 will be described with reference to FIG. FIG. 6 is a sequence diagram showing an example of the panoramic video distribution processing according to this embodiment. The subsequent steps S101 to S107 are repeatedly executed, for example, for each certain group of frame images of the panoramic video (for example, a frame image group of 1 second to several seconds).

  First, the video viewing processing unit 201 of the terminal 20 transmits a tile distribution request to the panoramic video distribution server 10 (step S101). Here, the tile distribution request includes, for example, the center coordinates of the visual field range or information for specifying the center coordinates.

The moving image distribution processing unit 101 of the panoramic moving image distribution server 10 determines whether the partial area tile or the zenith tile is to be distributed as the high quality tile by the determination unit 111 (step S102). That is, the determination unit 111 compares the vertical angle θ of the center coordinates of the visual field range with a predetermined threshold value (first threshold value Th ₁ and second threshold value Th ₂ ) to determine the partial area tile or the zenith tile. Which of the above is to be delivered is determined.

Here, when the vertical angle θ of the central coordinates is less than the first threshold Th ₁ and greater than the second threshold Th ₂ , the determination unit 111 determines to deliver the partial area tile as the high quality tile. On the other hand, when the vertical angle θ of the central coordinates is equal to or greater than the first threshold Th ₁ or equal to or less than the second threshold Th ₂ , the determination unit 111 determines to deliver the zenith tile as the high quality tile.

  The user may be able to set whether or not to use the zenith tile. When the use / nonuse of the zenith tile is set to “not used”, only the subsequent step S103 may be executed without performing the determination in step S102.

  When it is determined in step S102 that the partial area tile is to be distributed as the high-quality tile, the video distribution processing unit 101 of the panoramic video distribution server 10 causes the tile creating unit 112 to create the partial area tile as the high-quality tile (step S103). ). That is, the tile creating unit 112 creates a partial area tile that includes the visual field range and has a predetermined image size. Examples of the predetermined image size include HD size (1280 × 720) and full HD size (1920 × 1080). The image size to be used as the image size of the partial area tile is set in advance by the user, for example.

  On the other hand, when it is determined in step S102 that the zenith tile is to be distributed as the high quality tile, the video distribution processing unit 101 of the panoramic video distribution server 10 causes the tile creating unit 112 to create the zenith tile as the high quality tile (step). S104). That is, the tile creating unit 112 creates a zenith tile that includes the visual field range and that is specified by four predetermined vertices.

Here, when the vertical angle θ of the center coordinates is equal to or larger than the first threshold Th ₁ , the tile creation unit 112 causes the four vertices {(0, π), (0, θ ₁ ), (2π, θ ₁ ), Create a first zenith tile identified by (2π, π)}. On the other hand, when the vertical angle θ of the center coordinates is equal to or smaller than the second threshold Th ₂ , the tile creation unit 112 causes the four vertices {(0, θ ₂ ), (0, 0), (2π, 0), ( 2π, θ ₂ )} to create a second zenith tile.

  The tile creating unit 112 may compress the first zenith tile or the second zenith tile to the same image size as the partial area tile created in step S103.

  Following step S103 or step S104, the moving image distribution processing unit 101 of the panoramic moving image distribution server 10 causes the tile creating unit 112 to create an overall reduced tile as a low image quality tile (step S105). That is, the tile creating unit 112 creates an overall reduced tile by compressing the frame image of the panoramic video to the same image size as the partial area tile created in step S103.

  For example, when the frame image of the panoramic video is 4K size (3840 × 2160) and the partial area tile is HD size, the tile creating unit 112 creates an overall reduced tile by compressing the frame image to HD size.

  In steps S103 to S105 described above, a partial area tile or a zenith tile and an overall reduced tile are created from each frame image included in the frame image group.

  Next, the video distribution processing unit 101 of the panoramic video distribution server 10 distributes the high image quality tiles (partial area tiles or zenith tiles) and the low image quality tiles (whole reduction tiles) to the terminal 20 by the distribution unit 113 (step. S106).

  The video viewing processing unit 201 of the terminal 20 displays (reproduces) the panoramic video (high quality tile and low quality tile) distributed from the panoramic video distribution server 10 (step S107). At this time, the moving image viewing processing unit 201 expands the overall reduced tile to the original image size (that is, the size of the original frame image) and then reproduces the panoramic moving image. For example, when the frame image of the panoramic video is 4K size, the video distribution processing unit 101 expands the entire reduced tile to 4K size. This allows the user of the terminal 20 to view the panoramic video. It should be noted that, by performing compression and decompression, the overall reduced tile is displayed with lower image quality than the partial area tile and the zenith tile.

<Summary>
As described above, in the panoramic video distribution system 1 according to the present embodiment, the panoramic video distribution server 10 provides the high-quality tiles including the visual range and the low-quality tiles outside the visual range in response to the request from the terminal 20. To deliver. As a result, in the panoramic video distribution system 1 according to the present embodiment, even if the user of the terminal 20 moves the field of view out of the high quality tile, the panoramic video is reproduced by the low quality tile. You will be able to continue.

  In addition, the panoramic video distribution system 1 according to the present embodiment uses the high-quality tile instead of the partial area tile when the position of the visual field range on the omnidirectional projection sphere is close to the pole (North Pole or South Pole). Deliver zenith tiles to. As a result, in the panoramic video distribution system 1 according to the present embodiment, it is possible to secure a wide range of the effective area covered by the high-quality tile even when the visual field range on the omnidirectional projection sphere is very close. it can. Therefore, for example, when the user moves the field of view within the zenith tile, it is possible to provide the user with a high-quality panoramic video.

  In the panoramic video distribution system 1 according to the present embodiment, when the position of the visual field range on the omnidirectional projection sphere is close to the pole, the zenith tile is distributed as the high quality tile instead of the partial area tile. However, the aspect ratio of the partial area tiles to be distributed to the terminal 20 may be changed (for example, the lateral size of the partial area tiles may be increased toward the extreme). .

  Further, in the panoramic video distribution system 1 according to the present embodiment, regarding the case where the panoramic video distribution server 10 distributes the panoramic video to the terminal 20 via the network N (that is, the panoramic video is distributed via the network). Although explained, it is not limited to this. That is, in the present embodiment, for example, the terminal 20 has the function of the panoramic video distribution server 10, and the terminal 20 has the panoramic video in the local storage (for example, the panoramic video stored in the HDD or the like of the terminal 20). The same can be applied to the case of reproducing. This makes it possible to reduce the processing load and the like when the terminal 20 reproduces the panoramic video.

  The present invention is not limited to the above specifically disclosed embodiments, and various modifications and changes can be made without departing from the scope of the claims.

1 Panorama Video Distribution System 10 Panorama Video Distribution Server 20 Terminal 101 Video Distribution Processing Section 111 Judgment Section 112 Tile Creating Section 113 Distribution Section 201 Video Viewing Processing Section

Claims (9)

A video distribution device connected to a terminal for playing a panoramic video via a network,
Depending on the position of the range in which the frame image of the panoramic video is displayed on the terminal, the range includes the first high-quality image data of a predetermined image size, and the range, and the entire circumference Determination means for determining which of the second high image quality data including the vicinity of the pole when represented by the projection sphere is to be delivered to the terminal;
Creating means for creating the first high image quality data or the second high image quality data and low image quality data obtained by compressing the frame image to the image size according to a result of the determination made by the determining means;
Distribution means for distributing the first high image quality data or the second high image quality data and the low image quality data created by the creating means to the terminal;
A moving image distribution apparatus comprising: The creating means is
When it is determined by the determination means that the second high image quality data is to be delivered to the terminal, the third high image quality data is created by compressing the second high image quality data into the image size,
The delivery means is
The moving image distribution apparatus according to claim 1, wherein the third high image quality data and the low image quality data are distributed to the terminal. The determination means is
When the frame image of the panoramic video is represented by the equirectangular projection, when the vertical angle of the center coordinates of the range is less than the first threshold value and greater than the second threshold value, the first high quality image data is It is determined to deliver to the terminal, and when the vertical angle of the central coordinates is equal to or more than a first threshold value or less than the second threshold value, it is determined to deliver the second high image quality data to the terminal. The moving image distribution apparatus according to claim 1 or 2. The creating means is
When the determination unit determines that the second high-quality image data is to be delivered to the terminal, and when the vertical angle of the central coordinates is equal to or larger than the first threshold value, it is represented by a omnidirectional projection sphere. When the second high-quality image data including the vicinity of the North Pole is created, and the vertical angle of the central coordinates is equal to or smaller than the second threshold value, the second image including the vicinity of the South Pole when expressed by the omnidirectional projection sphere. The moving image distribution apparatus according to claim 3, wherein high-quality image data is created. A terminal connected via a network to a video distribution device that distributes panoramic video,
Depending on the position of the range in which the frame image of the panoramic video is displayed on the terminal, the range includes the first high-quality image data of a predetermined image size or the range, and the whole sky Receiving means for receiving, from the moving image distribution apparatus, second high-quality image data including the vicinity of a pole when represented by a circular projection sphere, and low-quality image data obtained by compressing the frame image to the image size.
Reproducing means for reproducing the panoramic video based on the first high image quality data or the second high image quality data and the low image quality data received by the receiving means;
A terminal characterized by having. A terminal that plays panoramic video,
Depending on the position of the range in which the frame image of the panoramic video is displayed on the terminal, the range includes the first high-quality image data of a predetermined image size, and the range, and the entire circumference Determination means for determining which of the second high image quality data including the vicinity of the pole when represented by the projection sphere is displayed on the terminal;
Creating means for creating the first high image quality data or the second high image quality data and low image quality data obtained by compressing the frame image to the image size according to a result of the determination made by the determining means;
Display means for displaying the first high image quality data or the second high image quality data and the low image quality data created by the creating means;
A terminal characterized by having. A video distribution system including a terminal for playing a panoramic video, and a video distribution device connected to the terminal via a network,
Depending on the position of the range in which the frame image of the panoramic video is displayed on the terminal, the range includes the first high-quality image data of a predetermined image size, and the range, and the entire circumference Determination means for determining which of the second high image quality data including the vicinity of the pole when represented by the projection sphere is to be delivered to the terminal;
Creating means for creating the first high image quality data or the second high image quality data and low image quality data obtained by compressing the frame image to the image size according to a result of the determination made by the determining means;
Distribution means for distributing the first high image quality data or the second high image quality data and the low image quality data created by the creating means to the terminal;
A video distribution system characterized by having. A video distribution device connected via a network to a terminal that plays panoramic video,
Depending on the position of the range in which the frame image of the panoramic video is displayed on the terminal, the range includes the first high-quality image data of a predetermined image size, and the range, and the entire circumference A determination procedure for determining which of the second high image quality data including the vicinity of the pole when represented by the projection sphere is to be delivered to the terminal;
A creation procedure for creating the first high-quality image data or the second high-quality image data and low-quality image data obtained by compressing the frame image to the image size according to the determination result of the determination procedure;
A delivery procedure for delivering the first high image quality data or the second high image quality data and the low image quality data created by the creating procedure to the terminal;
A video distribution method characterized by executing.   A program for causing a computer to function as each unit in the moving image distribution apparatus according to claim 1.

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