JPH1153521A - System, device, and method for image composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently composite an image by generating divided composite image data represented with object image data in a composition area and sending them to an image compositing device, and generating composite image data representing a composite image of one frame according to the divided composite images. SOLUTION: For example, when a background image BIP for printing is divided into three BDs 1 to 3 and the BD1 has no composition region, image composition is not necessary. When composition regions AC1 and AC2 are present in the divided background images BD2 and BD3 and the load of the composition process of the BD2 is larger than the load of the BD3, divided background data, etc., are sent to a division and composition server for the composition process of the BD2 and divided background image data, etc., are sent to the division and composition server as well for the composition process of the BD3, so that the composing processes of divided images are both performed. Then, an image management server generates composition image data representing a composite image of one frame from the division and composition image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image synthesizing system comprising one image synthesizing device and another image synthesizing device which can communicate with each other, an image synthesizing device and an image synthesizing method constituting the image synthesizing system.

[0002]

BACKGROUND OF THE INVENTION With the development of computer devices, it has become possible to synthesize a target image with a background image.
For example, a synthesis area for synthesizing the target image is defined in the background image, and the target image is synthesized with the synthesis area.

[0003] Both the image data representing the background image and the image data of the target image have a large data amount. For this reason, the load on the computer that performs the image synthesis becomes large. In a computer device with a low processing capability, image synthesis may require a relatively long time or image synthesis may not be possible.

[0004] In particular, when a composite image is printed, a high-resolution composite image is required, so that it takes time to synthesize the image.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to efficiently perform image composition processing.

An image synthesizing system according to the present invention is an image synthesizing system comprising one image synthesizing device capable of communicating with each other and a plurality of other image synthesizing devices. Dividing the background image of the target image to be divided into a plurality of pieces of background image, generating a plurality of pieces of divided background image data representing the plurality of divided background images, generating the plurality of pieces of divided background image data, Combined area data representing the position of the combined area and target image data representing the target image are transmitted from the one image combining apparatus to the other image combining apparatus, and the other image combining apparatus transmits the one image combining apparatus. Based on the divided background image data and the combined area data transmitted from
Divided composite image data generating means for generating divided composite image data representing a divided composite image by combining the target image represented by the target image data with the composite area, and the divided composite image data generated by the divided composite image data generating means And transmitting the divided combined image data to the one image combining device. The one image combining device is configured to transmit the divided combined image data based on the divided combined image data transmitted from the divided combined image data transmitting device. And a composite image data generating means for generating composite image data representing one frame of the composite image.

The present invention also provides an image synthesizing method suitable for implementing the above-described image synthesizing system. That is, this is an image synthesizing method of an image synthesizing system composed of one image synthesizing device and a plurality of other image synthesizing devices that can communicate with each other. The image is divided into a plurality of pieces, and a plurality of pieces of divided background image data representing a plurality of pieces of the divided background images are generated. The generated plurality of pieces of the divided background image data, the combination area where the target image is combined, and the position of the combination area are determined. Transmitting the combined area data to be represented and the target image data representing the target image from the one image combining device to the other image combining device, and the other image combining device transmits the combined image data transmitted from the one image combining device. By dividing the target image represented by the target image data into the synthesis area based on the divided background image data and the synthesis area data, Generating divided combined image data representing an image; transmitting the divided combined image data generated by the divided combined image data generating means to the one image combining device in the other image combining device; Based on the divided combined image data transmitted from the transmitting means, the one image combining apparatus generates combined image data representing one frame of the combined image.

According to the present invention, the plurality of other image synthesizing devices generate the divided image data representing the divided image. The generated divided image data is transmitted from the plurality of other image synthesizing devices to the one image synthesizing device. In the one image synthesizing device, one frame of a synthesized image is generated from the divided image data transmitted from the plurality of other image synthesizing devices.

Since the divided composite image generation processing is performed in a distributed manner by the plurality of other image synthesizing devices, the amount of image data processed by each of the other image synthesizing devices is reduced. Since the load on the other image synthesizing devices is reduced, quick image synthesizing becomes possible. An image synthesizing process can be performed even with an image synthesizing device having a relatively low processing capability.

[0010] Preferably, the processing capability relating to image synthesis in the other image synthesizing device is detected, and the divided background image data, the composite area data and the target image data to be transmitted are based on the detected processing capability. Another image synthesizing device is determined.

The other image synthesizing apparatus having high processing ability includes
The divided background image data, the combined area data, and the target image data, which have a high combined load of the divided images, can be transmitted. More efficient image synthesis processing can be performed.

When the client computer can communicate with the one image synthesizing device, the client computer transmits the image data to be synthesized, and the one image synthesizing device transmits the image data from the client computer. The received composition target image data is received. The received image data to be combined is transmitted to the other image combining device, and the divided combining is performed.

The combination area and the position of the combination area can be determined by image data representing a plurality of combination area defining images (mask images) corresponding to one frame of image by combining them.

Further, the one image synthesizing device and the other image synthesizing device constituting the image synthesizing system may be independently constituted.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall configuration of an image synthesizing system according to this embodiment.

The image management server 30 includes the divided image server 4
OA, 40B and 40C can communicate with each other. The image management server 30 is a server that controls processing in the divided image servers 40A, 40B, and 40C.

The client computer 1 can mutually communicate with the image management server 30.

In an image synthesizing system, editing template image data representing an editing template image (relatively low resolution and a small amount of image data) that defines a position where an object image is to be synthesized and an area thereof is defined as an image. Sent from the management server 30 to the client computer 1. The user of the client computer 1
An image owned by the user is combined with the editing template image represented by the transmitted editing template image data. Image data representing an image of the user and synthesis information for image synthesis are transmitted from the client computer 1 to the image management server 30 from the client computer 1. In the image management server 30 and the divided image servers 40A, 40B and 40C, an image synthesizing process is performed. This image synthesis processing is performed in a distributed manner using the plurality of image servers 40A, 40B, and 40C. The details of the image synthesizing process will be apparent from the following description.

FIG. 2 is a block diagram showing the electrical configuration of the client computer 1. The client computer 1 is usually placed at the user's home.

The overall operation of the client computer 1 is controlled by the CPU 2.

The client computer 1 has an RO
M3, RAM 4 for temporarily storing data, VRAM 12 for temporarily storing image data for displaying an image on the display device 14 for image synthesis, reading of data from ROM 3, writing of data to RAM 4 and VRAM 12, and Memory to control reading
A controller 15 is included. The image data read from the VRAM 12 is supplied to the DA converter 13 so that the image data is converted into an analog video signal,
Will be displayed.

The client computer 1 is connected to a bus controller 5, a memory controller 15, and a timer 16.

Further, a system I / O controller 6 is connected to the client computer 1.
This system I / O controller 6 includes a client
Keyboard 7 and mouse 8 for receiving an operation command from a user of computer 1, CD-ROM drive 9 and FD drive 10 for reading image data, and a modem for connecting to image management server 30 via a public telephone line. 11 are connected.

The client computer 1 has an external I
/ O controller 18 is connected. This external I /
The O-controller 18 has a flatbed scanner 2
1, a film scanner 22, a digital still camera 23, and an HD drive 24 are connected. H
HD that can read and write data freely by D drive 24
An operation program is read from a hard disk (not shown). (This operation program is installed in the client computer 1 by loading a CD-ROM storing the program into a CD-ROM drive 9 described later and reading the program.) And stored in the HD). By reading the operation program stored in the HD, predetermined processing described later is performed by the client computer 1. As shown in FIG. 3, the hard disk stores image data representing user images (target images) U1 and U2 to be combined.

Further, a printer 20 for printing an image and a printer control circuit 19 for controlling the printer 20 are connected to the client computer 1.

The user uses the client computer 1 to synthesize a user image with an editing template image. Details of the image synthesizing process will be described later.

FIG. 4 is a block diagram showing the electrical configuration of the image management server 30. In this figure, the same components as those shown in FIG. The division / combination servers 40A, 40B and 40C have the same configuration as the image management server 30. The image management server 30 (split composition servers 40A, 40B, and 40C) also loads the CD-ROM storing the program into the CD-ROM drive 9 and reads the operation program to operate the image management server 30 (split image servers 40A, 40B). And 40
C) and stored in the HD.

External I / O included in the image management server 30
A high-speed film scanner 25 is connected to the controller 18.

The image management server 30 is connected to a high-quality printer 20A capable of high-quality printing.

On the hard disk of the image management server 30, a large number of data representing a mask image MD for divided printing (see FIG. 5) and a large number of data representing a background image for printing (see FIG. 9A) BIP are recorded.

FIG. 5 shows an example of the divided printing mask image MD. 6 (A), (B), FIG. 7 (A),
FIGS. 8B and 8A and 8B show how a printing mask image is generated from a divided printing mask image. 9A shows a printing background image BIP, and FIG. 9B shows a printing mask image formed on the basis of printing mask image configuration information (in FIG. 9B, a printing mask image is shown for easy understanding). The divided printing mask image MD is composed of
(C) show an editing background image, and (D) shows an editing mask image.

First, a template image for printing is generated by a template generating device (not shown; this template generating device can also be constituted by the image management server 30 or the divided image servers 40A, 40B or 40C) (step). 51). The print template image is generated as follows.

Image data representing the mask image for divided printing shown in FIG. 5 is read from the template image generating device. The operator of the template image generation apparatus displays the read divisional printing mask image MD in FIG.
By combining as shown in FIGS. 8A and 8A, a print mask image MP is generated (see FIGS. 6B, 7B and 8B). Here, FIG.
It is assumed that a print mask image MP as shown in FIGS. 9A and 9B has been generated (see also FIG. 9B). The division printing mask image MD defines a combination area AC for combining user images. 6A and 6B, a first combined area AC1 and a second combined area AC2 are provided in the printing mask image MP.

Image data representing the generated print mask image MP is thinned out at predetermined thinning rates in the horizontal and vertical directions, respectively. By this thinning processing, FIG.
An editing mask image ME as shown in (D) is generated (here, the editing mask image ME is smaller in order to indicate that the image data amount of the editing mask image is smaller than the data amount of the printing mask image). The size of the mask image is smaller than the size of the printing mask image).

The template image generating apparatus records image data representing a large number of background images for printing. Image data representing a printing background image is read from the template image generation device, and a desired printing background image BIP is selected by an operator.

The image data representing the selected printing background image is thinned out at predetermined thinning rates in the horizontal and vertical directions, respectively. By this thinning processing, image data representing the background image for editing BIE shown in FIG. 9C is generated (steps 51 and 52).

In the template generating apparatus, FIG.
As shown in (A), the background image for printing BIP is selected,
Further, as shown in FIGS. 9B, 9C and 9D, when the print mask image, the edit background image BIE and the edit mask image ME are generated, image data representing the print background image, The printing mask image configuration information, the editing background image data, and the image data combining the editing mask image for generating the printing mask image by combining the divided printing mask images are transmitted from the template generating apparatus to the image management server 30. Is done.

On the hard disk of the image management server 30,
The image data representing the printing background image, the printing mask image configuration information, the image data representing the editing background image, and the image data representing the editing mask image transmitted from the template generating apparatus are recorded (step 53).

The image management server 30 is in a standby state until a request for transmitting a template from the client computer 1 is received. When the image management server 30 receives the template request from the client computer 1 (steps 61 and 54), the image management server 30
Generates an editing template image TE. The editing template image is generated by superimposing the editing background image on the editing mask image. That is, when the editing background image is overlaid on the editing mask image, the image of the editing background image BIE is displayed in the hatched area of the editing mask image ME, and the combining area is displayed in the editing mask image ME. Area A shown as
Synthetic area AC of editing mask image ME on C1 and AC
1 and AC2 are displayed on the editing template image T
E is generated (see FIG. 10).

When there is a request for transmission of template image data from the client computer 1, the generated editing template image data is transmitted from the image management server 30.
It is transmitted to the client computer 1 (step 55).

In the client computer 1,
When the editing template image data is received (step 62), the editing template image TE is displayed on the display screen of the display device 14 of the client computer 1.

The user of the client computer 1 reads from the hard disk the user images U1 and U2 to be combined with the combining areas AC1 and AC2 of the editing template image TE, and displays the editing template image TE displayed on the display unit 14. (Step 63). As a result, the composite image IC is displayed on the display device 1 of the client computer 1.
4 is displayed. FIG. 11 shows an example of the composite image IC.

When the composite image IC desired by the user is generated (step 63), the data representing the request for printing the composite image IC contains the user image U1 required for generating the composite image IC.
And U2 and synthesis information for generating a synthesized image (synthesis information is data for specifying the printing background image BIP, printing mask image configuration information, and data indicating which user image is to be synthesized with which synthesis area. Is transmitted from the client computer 1 to the image management server 30 (step 64).

The image management server 30 receives a print request from the client computer 1 (step 5).
6). When the print request is received, the divided image server 4
A composite image for printing is generated using 0A, 40B, and 40C (step 57). The process of generating the composite image will be described later in detail. When the composite image for printing is generated, a high-definition composite image is printed by the high-quality printer 20A (step 58).

FIG. 13 shows how a composite image for printing is generated, and FIG. 14 is a flowchart showing a processing procedure when generating a composite image for printing.

When there is a request for composite printing from the client computer 1, the image management server 30 searches the transmitted image composition information for a printing background image BIP to be used for generating a composite image. Further, image data representing a plurality of divided print mask images MD for forming a print mask image is searched from the print mask image configuration information included in the image synthesis information.

Based on the printing mask image configuration information,
The printing background image BIP represented by the searched printing background image data is converted into a plurality of divided printing mask images MD.
(Step 71) (here, the divided printing background images BD1, BD2, and BD3).
Divided into two).

The load of the combining process when combining images for each of the divided printing background images BIP is calculated for each of the divided printing background images BD1, BD2 and BD3 (step 72). First divided printing background image B
If the image combining area does not exist in the divided print background image as in D1, the load of the image combining processing is calculated to be no. If the image combining areas AC1 and AC2 are present in the divided print background images as in the second divided print background image BD1 and the third divided print background image BD2, the data amount of the image data representing the print mask image Thus, the load of the image synthesis processing is detected. If the amount of image data representing the printing mask image is large, the load of the image combining process is determined to be large, and if the amount of image data representing the printing mask image is small, the image combining processing load is determined to be small.

Subsequently, the division / combination servers 40A and 40B
State parameters (CPU processing capacity, R
Transmission of the remaining capacity of the AM4 and the remaining capacity of the hard disk is requested (step 73). Split synthesis server 40
When the status parameters are transmitted from A, 40B, and 40C (step 74), detection of the split synthesis server having no processing capability and calculation of the pass rate of split synthesis servers 40A, 40B, and 40C are performed based on the received status parameters. Performed (step 75). The detection of the divided image server having no processing capability and the pass rate thereof are calculated as follows.

The amount of image data of the divided image area (the background image BD for divided printing, the amount of all image data of the divided printing mask image MD and the user image) is represented by FS, and the processing capability of the CPU among the state parameters is represented by the CPU and RAM 4. Assuming that the remaining capacity is MC and the remaining capacity of the hard disk is DC, Equation 1
A divided image server that does not satisfy both the conditions of Expression 2 and Expression 2 is determined to be an image server having no processing capability.

FC <MC Expression 1

FS <DC Expression 2

Next, the evaluation value V1 (CPU) and the evaluation value V2
(FS / MS) and the evaluation value V3 (FS / DC) are calculated. These calculated evaluation values V1,
V2 and V3 are substituted into the following equation, and the pass rate is calculated.

Pass rate = (K1 × V1 + K2 × V2 + K3 × V3) / 3 Expression 3

However, K1, K2 and K3 are weighting factors, and are set so that the sum of these weighting factors is three.

In this way, it is determined that the divided image server having a small pass rate among the calculated pass rates has a high ability of the image synthesizing process.

When the processing capacity of each of the divided image servers is detected, the divided image background image data and the divided printing mask are set so that the divided image server having a higher processing capacity performs the divided composition with a higher load of the image composition processing. Image data, user image data representing a user image to be combined with the combination area, and combination information are transmitted (step 76). When these image data and the like are transmitted to the division / combination server having high processing capability, the processing capability of the division / combination server is updated (step 77).

Steps 76 and 77 are repeated until all print image data and the like for the divisional synthesis are transmitted to any of the divisional image servers (step 78).

For example, as shown in FIG. 13, when the printing background image BIP is divided into three printing background images BD1, BD2 and BD3, the first printing divided background image BD1 has no combined area. In some cases, it is not necessary to perform image composition on the first divided background image for printing BD1. The second divided background image for printing BD2 and the third background image for printing BD3 include a combining area AC1.
And AC2, the second divided background image BD for printing
It is assumed that the load of the combining process of No. 2 is larger than the load of the combining process of the third divided background image for printing BD3. In addition, it is assumed that the processing capacity of the split combining server 40A is the highest among the split combining servers 40A, 40B, and 40C, and the processing capacity of the split combining server 40B is the next highest.

In this case, the second printing background image BD
The divided background image data and the like for the divided composition are transmitted to the divided composition server 40A for the composition processing in 2, and the divided image composition processing is performed in the divided composition server 40A. Further, the divided background image data and the like for the divisional composition are transmitted to the divisional composition server 40B for the composition processing in the third printing background image BD3, and the divided composition server 4
At 0B, a synthesis process of the divided images is performed.

When the division / combination is completed in each of the division / combination servers, the data indicating the completion of the division / combination and the divided / combined divided image data are divided into the division / combination servers 40A, 40A.
B and 40C transmit to the image management server 30 (steps 79 and 80).

Each of the divided image servers 40A, 40B and 4
When the divided combined image data is transmitted from 0C, the image management server 30 generates combined image data representing one frame of the combined image from the divided combined image data (step 81). The synthesized image data generated in this manner is transmitted to the high-quality printer 20A of the management image server 30, whereby the high-quality synthesized image is printed as described above.

The printed composite image will be transmitted to the user of the client computer 1 by mail, for example.

[Brief description of the drawings]

FIG. 1 shows the overall configuration of an image composition system.

FIG. 2 shows an electrical configuration of a client computer.

FIG. 3 shows an example of a user image.

FIG. 4 shows an electrical configuration of the image management server.

FIG. 5 shows an example of a mask image for divided printing.

FIG. 6A shows an example in which divided print mask images are combined, and FIG. 6B shows an example of a print mask image.

FIG. 7A shows an example in which divided print mask images are combined, and FIG. 7B shows an example of a print mask image.

FIG. 8A shows an example in which divided print mask images are combined, and FIG. 8B shows an example of a print mask image.

9A shows a printing background image, FIG. 9B shows a printing mask image constituted by printing mask image configuration information, FIG. 9C shows an editing background image, and FIG. Indicates an editing mask image.

FIG. 10 shows an editing template image.

FIG. 11 shows a user composite image.

FIG. 12 is a flowchart illustrating an outline of an image combining process.

FIG. 13 shows a state of image synthesis.

FIG. 14 is a specific flowchart of a synthetic image generation process.

[Explanation of symbols]

 Reference Signs List 1 client computer 2 CPU 20A high quality printer 30 image management server 40A, 40B, 40C split synthesis server

Claims (12)

[Claims] 1. An image synthesizing system comprising one image synthesizing device and a plurality of other image synthesizing devices which can communicate with each other, wherein the one image synthesizing device includes a background image of a target image to be synthesized. Is divided into a plurality of pieces, and a plurality of pieces of divided background image data representing a plurality of divided background images are generated, and the plurality of pieces of generated divided background image data, a combined area where the target image is combined, and a position of the combined area are represented. Transmitting the combined area data and the target image data representing the target image from the one image combining device to the other image combining device;
The other image synthesizing apparatus synthesizes a target image represented by the target image data with the synthesis area based on the divided background image data and the synthesis area data transmitted from the one image synthesis apparatus. Dividing combined image data generating means for generating divided combined image data representing a divided combined image by means of, and dividing and combining the divided combined image data generated by the divided combined image data generating means to the one image combining device. Image data transmitting means, wherein the one image synthesizing device generates synthetic image data representing one composite image based on the divided synthetic image data transmitted from the divided synthetic image data transmitting means. Means for synthesizing an image. 2. The image combining apparatus according to claim 1, wherein said one image synthesizing apparatus includes an image synthesizing processing capacity detecting means for detecting a processing capacity related to image synthesizing in said another image synthesizing apparatus, and a processing capacity detected by said image synthesizing processing capacity detecting means. 2. The image synthesizing system according to claim 1, further comprising a transmitting device determining unit that determines the other image synthesizing device to which the divided background image data, the composite area data, and the target image data are to be transmitted. 3. The image compositing apparatus according to claim 1, wherein said client computer is capable of communicating with said one image synthesizing apparatus, and said image data to be synthesized is transmitted from said client computer. 2. The image synthesizing system according to claim 1, further comprising a synthesis target image data receiving unit that receives the synthesis target image data transmitted from the client computer. 4. The image according to claim 1, wherein the combined area and the position of the combined area are determined by image data representing a plurality of combined area defining images corresponding to one frame of image when combined. Synthetic system. 5. A divided background image data generating means for dividing a background image of a target image to be synthesized into a plurality of divided background image data and generating a plurality of divided background image data representing the plurality of divided background images. Transmitting means for transmitting the generated divided background image data, a composite area in which the target image is composited, composite area data indicating the position of the composite area, and target image data representing the target image to another image synthesizing apparatus; On the basis of divided combined image data representing a divided combined image in which a target image is combined with the combined area based on the divided background image data and the combined area data generated by another image combining apparatus,
An image synthesizing apparatus, comprising: synthetic image data generating means for generating synthetic image data representing one frame of a synthetic image. 6. A plurality of divided background image data representing a plurality of divided background images obtained by dividing a background image of a target image to be combined into a plurality of pieces, a combining area in which the target image is combined, and a combining representing a position of the combining area. A divided combined image data generating means for combining the target image with the combined area based on the area data to generate divided combined image data representing the divided combined image; and the divided combined image generated by the divided combined image data generating means An image synthesizing apparatus comprising: a divided synthesized image data transmitting unit that transmits image data to another image synthesizing apparatus. 7. An image synthesizing method for an image synthesizing system comprising one image synthesizing device and a plurality of other image synthesizing devices that can communicate with each other, wherein the one image synthesizing device is an object to be synthesized. A background image of an image is divided into a plurality of pieces, a plurality of pieces of divided background image data representing a plurality of divided background images are generated, the generated plurality of pieces of divided background image data, a synthesis area where the target image is synthesized, and the synthesis area Is transmitted from the one image synthesizing device to the other image synthesizing device, and is transmitted from the one image synthesizing device to the other image synthesizing device. The target image represented by the target image data is combined with the composite region based on the divided background image data and the composite region data thus divided. Generating divided composite image data representing the composite image; transmitting the divided composite image data generated by the divided composite image data generating means to the one image compositing device in the other image compositing device; An image synthesizing method, wherein the one image synthesizing device generates synthetic image data representing one frame of a synthetic image based on the divided synthetic image data transmitted from the data transmitting means. 8. The image processing apparatus according to claim 1, further comprising: detecting a processing capability related to image synthesis in said another image synthesizing device, and transmitting said divided background image data, said composite region data and said target image data based on the detected processing capability. The image synthesizing method according to claim 7, wherein the image synthesizing device is determined. 9. The image processing apparatus according to claim 9, wherein the client computer is communicable with the one image synthesizing device, the image data to be synthesized is transmitted from the client computer, and the one image synthesizing device is The image composition system according to claim 7, wherein the composition object image data transmitted from the client computer is received. 10. The image according to claim 7, wherein the combination area and the position of the combination area are determined by image data representing a plurality of combination area defining images corresponding to one frame of image when combined. Synthesis method. 11. A background image of a target image to be combined is divided into a plurality of background images, a plurality of divided background image data representing a plurality of divided background images is generated, and the generated divided background image data and the target image are combined. Transmitting the combined area data indicating the position of the combined area and the combined area and the target image data representing the target image to another image combining apparatus, and generating the divided background image data and the divided image data generated by the other image combining apparatus. An image synthesizing method for generating composite image data representing one frame of composite image based on divided composite image data representing a divided composite image in which a target image is composited in the composite region based on the composite region data. 12. A plurality of divided background image data representing a plurality of divided background images obtained by dividing a background image of a target image to be combined into a plurality of pieces, a combining area in which the target image is combined, and a combining indicating a position of the combining area. The target image is combined with the combined area based on the area data to generate divided combined image data representing the divided combined image, and the divided combined image data generated by the divided combined image data generating unit is combined with another image combined. An image synthesis method to be transmitted to the device.