WO2016035995A1 - Cloud streaming service system, cloud streaming service method for saving system resources, and apparatus therefor - Google Patents

Abstract

Disclosed are a cloud streaming service system, a cloud streaming service method for saving system resources, and an apparatus therefor. An execution screen of an application which is executed for a cloud streaming service is captured, a key frame is extracted from the execution screen, still image compression information corresponding to the key frame is generated, still image encoding on the execution screen is performed by applying a still image compression information-based still image compression technique to at least one of the key frame and the remaining frames except for the key frame in the execution screen, the still image compression encoded execution screen is transmitted to a user's terminal device, and thereby a still image-based cloud streaming service can be carried out. It is possible to provide a cloud streaming service to more users by saving system resources for generating still image compression information of a subframe.

Description

Cloud streaming service system, cloud streaming service method for saving system resources, and apparatus therefor

Cloud streaming service system, cloud streaming service method for saving system resources, and a device for the same (SYSTEM FOR CLOUD STREAMING SERVICE, METHOD OF CLOUD STREAMING SERVICE TO SAVE SYSTEM RESOURCES AND APPARATUS FOR THE SAME) In streaming service, similar scenes are divided into key frames and subframes, and still image compression information corresponding to the key frames is generated and applied to the subframes to save system resources. Cloud streaming service system that can generate application result screen with animation effect on user terminal by transmitting generated code with the captured image to user, cloud streaming to save system resources It relates to a service method and an apparatus therefor.

The present invention claims the benefit of the date of application of Korean Patent Application No. 10-2014-0115670 filed September 1, 2014 and Korean Patent Application No. 10-2014-0170423 filed December 2, 2014, the contents of all Is included herein.

Recently, as a variety of applications driven in a mobile communication terminal such as a smartphone have been developed, a number of virtualization technologies for driving an application requiring high performance for execution in a relatively low performance user terminal have been proposed. Among them, a cloud streaming technology, which compresses and streams a screen into a video and provides the same to a user's terminal, and plays a streamed screen on the terminal as if an application is running on the terminal, has been in the spotlight.

In the case of such cloud streaming-based service, the requests of many users must be processed at the same time, and as many applications as the number of connected users must be run on the server side, utilizing the resources of the prepared system as efficiently as possible to use the cloud streaming service smoothly. It can be a key part of providing it.

It also renders only the minimum required portion of the execution result screen of the application executed by the user's request, and provides information related to the animation separately from the image so that the screen does not need to be unnecessarily captured even when dynamic effects such as animation are applied. By transmitting to a set-top box, a technology that can create a service screen with an animated effect in the set-top box is urgently emerging.

Related prior arts include Korean Patent Application Publication No. 10-2014-0041317, published April 04, 2014 (name: transmission of video using static content information from a video source) and Korean Patent Application Publication No. 10-2010-0113503 Issue, October 21, 2010 (name: System and Method for Storing Program Code and Data in an Application Hosting Center).

An object of the present invention is to increase the compression rate of data by using a still image compression technique when providing a still image-based cloud streaming service to prevent transmission delays that may occur when the still image-based cloud streaming.

It is also an object of the present invention to pre-configure still image compression information for important frames among similar parts of the service scene, and reuse the system resources necessary for generating still image compression information by reusing when encoding similar frames as important frames. To save.

In addition, an object of the present invention is to provide an improved cloud streaming service by omitting the process of comparing the frame difference in order to generate an image to be captured by the cloud streaming server, and by acquiring the image at the code stage.

It is also an object of the present invention to increase the number of web containers that can be driven in a server by avoiding unnecessary animation processing when processing an application result screen.

In addition, an object of the present invention is to enable a web application developer to provide a cloud streaming service for performing the application of animation effects in the user terminal even if the application code of the desired format is written in the existing manner, not the new format code. .

Cloud streaming server according to the present invention for achieving the above object, the capture unit for capturing the execution screen of the application executed for the cloud streaming service; A key frame extracting unit extracting a key frame of the execution screen; Generating still image compression information corresponding to the key frame, and applying a still image compression technique based on the still image compression information to one or more of the remaining frames other than the key frame and the key frame among the execution screens An encoding unit for encoding a still image of the execution screen; And a sending unit configured to transmit the still image encoded execution screen to a user's terminal device to perform a still image based cloud streaming service.

In this case, the encoder may extract a subframe having a change value of the frame less than a predetermined reference value from the remaining key frames, and compress the subframe using the still image compression technique.

In this case, the key frame may be a frame in which the change value of the frame is greater than or equal to the preset reference value in comparison with the previous frame of the execution screen.

In this case, the still image compression information may include one or more of a palette, a color substitution table, and an optimal filter.

In this case, the encoding unit may compress the subframe using the still image compression technique based on the still image compression information until the next key frame of the key frame appears.

In this case, the encoding unit may store the key frame and the still image compression information in a database in association.

In this case, the key frame extracting unit may calculate the change value of the frame in consideration of the change of the pixel value of the execution screen.

In this case, the key frame extracting unit may extract the key frame in consideration of at least one of the input signal of the application and the number of additional colors.

In this case, the encoding unit may encode a still image of the execution screen by using a paletted portable network graphics (PNG) still image compression method using the still image compression information.

In addition, the cloud streaming service method for saving system resources according to the present invention, capturing an execution screen of an application executed for the cloud streaming service; Extracting a key frame from the execution screen; Generating still image compression information corresponding to the key frame, and applying a still image compression technique based on the still image compression information to one or more of the remaining frames other than the key frame and the key frame among the execution screens Encoding a still image of the execution screen; And performing a still image-based cloud streaming service by transmitting the still image encoded execution screen to a user's terminal device.

In this case, the encoding may include extracting a subframe having a change value of the frame less than a predetermined reference value from the remaining key frames, and compressing the subframe using the still image compression technique. can do.

At this time, the key frame can save the system resources, characterized in that the change value of the frame compared to the previous frame of the execution screen is a frame of more than the predetermined reference value.

In this case, the still image compression information may include one or more of a palette, a color substitution table, and an optimal filter.

In this case, the encoding may compress the subframe using the still image compression technique based on the still image compression information until the next key frame of the key frame appears.

In this case, the encoding may save system resources, wherein the key frame and the still image compression information are interlocked and stored in a database.

In this case, the extracting of the key frame may calculate the change value of the frame in consideration of the change of the pixel value of the execution screen.

In this case, the extracting of the key frame may extract the key frame in consideration of at least one of the input signal of the application and the number of additional colors.

In this case, the encoding may include still image encoding of the execution screen using a paletted portable network graphics (PNG) still image compression technique using the still image compression information.

In addition, as another means for solving the problem of the present invention, there is provided a computer program stored in the medium for executing the above-described method.

In addition, the cloud streaming service system according to the present invention captures an execution screen of an application executed for the cloud streaming service, extracts a key frame of the execution screen, the remaining frames and the key other than the key frame of the execution screen Applying a still image compression technique based on still image compression information corresponding to the key frame to at least one of the frames, and still encoding the execution screen, and transmitting the still image encoded execution screen to a user terminal device. Cloud streaming server for performing a still image-based cloud streaming service; And a terminal receiving an application execution result screen corresponding to the cloud streaming service from the cloud streaming server.

In addition, a cloud streaming server according to another embodiment of the present invention for achieving the above object, the code receiving unit for receiving a first code corresponding to the application result screen from the web application server; A capture unit to generate a captured image by using image area attribute information included in the first code; An encoding unit for still image encoding the captured image using a still image compression technique; And a still image-based cloud by transmitting the still image encoded capture image and the second code generated to include the animation information to the user terminal so as to generate the application result screen in the user terminal. It includes a sender for performing a streaming service.

In this case, the capture unit may generate the captured image by performing rendering on input information corresponding to the image region property information included in the first code.

In this case, the cloud streaming server may include a capture image information generation unit configured to generate capture image information by using the image area attribute information included in the first code; An animation information generator configured to generate the animation information by using the animation code included in the first code; And a code converter configured to convert the first code into the second code including the captured image information and animation information.

In this case, the capture unit may generate the captured image by performing the rendering only on a part of the application result screen.

In this case, the second code may include the animation information corresponding to at least one or more of an animation type, an animation application time, an animation repetition number, a start coordinate, an end coordinate, a start size, and an end size.

In this case, the second code may not include the animation code.

In this case, the encoding unit may encode still images of the captured image using a still image compression technique corresponding to any one of portable network graphics (PNG), palletized portable network graphics (PNG), and joint photography experts group (JPEG). have.

In addition, the image cloud streaming service method using the application code according to the present invention, the step of receiving a first code corresponding to the application result screen from the web application server; Generating a captured image by using image region attribute information included in the first code; Still image encoding the captured image using a still image compression technique; And converting the still image-encoded capture image and the first code to generate the application result screen in a user terminal, and transmitting a second code generated to include animation information to the user terminal to generate the application result screen. Performing a streaming service.

In this case, the generating of the captured image may generate the captured image by rendering the input information corresponding to the image region attribute information included in the first code.

In this case, the cloud streaming service method may further include generating captured image information by using the image area attribute information included in the first code; Generating the animation information by using an animation code included in the first code; And converting the first code into the second code including the captured image information and animation information.

In this case, the generating of the captured image may generate the captured image by performing the rendering only on a part of the application result screen.

In this case, the second code may include the animation information corresponding to at least one or more of an animation type, an animation application time, an animation repetition number, a start coordinate, an end coordinate, a start size, and an end size.

In this case, the second code may not include the animation code.

In this case, the encoding of the still image may be performed by using a still image compression technique corresponding to any one of portable network graphics (PNG), paletted portable network graphics (PNG), and joint photography experts group (JPEG). Image can be encoded.

In addition, as another means for solving the problem of the present invention, there is provided a computer program stored in the medium for executing the above-described method.

In addition, the cloud streaming service system according to another embodiment of the present invention receives a first code corresponding to the application result screen from the web application server, and generates a captured image using the image area attribute information included in the first code And converting the still image encoded capture image and the first code using a still image compression technique to transmit a second code generated to include animation information to a user terminal to perform a still image-based cloud streaming service. Cloud streaming server; And a terminal receiving an application execution result screen corresponding to the still image-based cloud streaming service from the cloud streaming server.

According to the present invention, by using an appropriate still image compression technique when providing a still image-based cloud streaming service to increase the compression rate of the data it is possible to prevent the transmission delay that may occur when the still image-based cloud streaming.

In addition, the present invention can pre-configure still image compression information for important frames among similar parts of the service scene and reuse them when encoding frames similar to the important frames to save the system resources necessary for generating still image compression information as much as possible. Can be.

In addition, the present invention can provide an improved cloud streaming service by omitting the process of comparing the frame difference to generate an image to be captured by the cloud streaming server and acquires the image at the code end.

In addition, the present invention can increase the number of web containers that can be driven in the server by avoiding unnecessary animation processing when processing the application result screen.

In addition, the present invention can provide a cloud streaming service for performing the application of animation effects in the user terminal even if the web application developers write the application code of the desired format in a conventional manner rather than a new format code.

1 is a block diagram showing a cloud streaming service system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of a cloud streaming server of FIG. 1.

3 is a diagram illustrating a key frame and a sub frame according to an embodiment of the present invention.

4 is an operation flowchart illustrating a cloud streaming service method for saving system resources according to an embodiment of the present invention.

5 is an operation flowchart showing in detail a cloud streaming service method for saving system resources according to an embodiment of the present invention.

6 is a block diagram showing a cloud streaming service system according to another embodiment of the present invention.

FIG. 7 is a block diagram illustrating an example of a cloud streaming server of FIG. 6.

8 is a diagram illustrating performing a still image-based cloud streaming service according to an embodiment of the present invention.

9 illustrates a first code and a second code according to an embodiment of the present invention.

10 is a diagram illustrating code conversion according to an embodiment of the present invention.

11 is a diagram illustrating code conversion according to another embodiment of the present invention.

12 is a flowchart illustrating an image cloud streaming service method using an application code according to an embodiment of the present invention.

13 is a flowchart illustrating a code conversion process according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the following description and the accompanying drawings, detailed descriptions of well-known functions or configurations that may obscure the subject matter of the present invention will be omitted. In addition, it should be noted that like elements are denoted by the same reference numerals as much as possible throughout the drawings.

The terms or words used in the specification and claims described below should not be construed as being limited to ordinary or dictionary meanings, and the inventors are appropriate as concepts of terms for explaining their own invention in the best way. It should be interpreted as meanings and concepts in accordance with the technical spirit of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention, and various alternatives may be substituted at the time of the present application. It should be understood that there may be equivalents and variations. In addition, terms such as “first” and “second” are used to describe various components, and are only used to distinguish one component from another component and are not used to limit the components.

1 is a block diagram showing a cloud streaming service system according to an embodiment of the present invention.

Referring to FIG. 1, a cloud streaming service system according to an exemplary embodiment of the present invention includes a cloud streaming server 110, terminal devices 120-1,..., 120 -N, and a network 130. .

The cloud streaming server 110 captures an execution screen of an application executed for the cloud streaming service.

In addition, the cloud streaming server 110 extracts a key frame of the execution screen. In this case, the key frame may be a frame in which the change value of the frame is greater than or equal to a preset reference value in comparison with the previous frame in the execution screen. In this case, the change value of the frame may be calculated in consideration of the change of the pixel value of the execution screen. In this case, the key frame may be extracted in consideration of at least one of the input signal of the application and the number of additional colors.

In addition, the cloud streaming server 110 generates still image compression information corresponding to the key frame, and compresses the still image based on the still image compression information on one or more of the remaining frames and key frames except the key frame in the execution screen. The technique is applied to still image encoding of the execution screen. In this case, a subframe having a change value of a frame less than a predetermined reference value may be extracted from the remaining frames, and the subframe may be compressed using a still image compression technique. In this case, the still image compression information may include one or more of a palette, a color substitution table, and an optimal filter. At this time, the subframe may be compressed by using a still image compression technique based on still image compression information until the next key frame of the key frame appears. In this case, the key frame and the still image compression information may be linked to and stored in the database. In this case, a still image may be encoded using a paletted portable network graphics (PNG) still image compression technique using still image compression information.

In addition, the cloud streaming server 110 transmits a still image encoded execution screen to the terminal devices 120-1,..., 120 -N of the user to perform a cloud image service based on a still image.

The terminal devices 120-1,..., 120 -N receive an application execution result screen corresponding to the cloud streaming service from the cloud streaming server 110 and provide the result to the user.

The terminal devices 120-1,..., 120 -N are devices connected to a communication network to execute an application based on a cloud computing system, and are not limited to mobile communication terminals, but all information communication devices and multimedia terminals. It may be a variety of terminals, such as a wired terminal, a fixed terminal and an IP (Internet Protocol) terminal. In addition, the terminal devices 120-1,..., 120 -N are respectively mobile phones, portable multimedia players (PMPs), mobile internet devices (MIDs), smart phones, desktops, and tablet computers. Number of mobile terminals with various mobile communication specifications such as Tablet PC, Note book, Net Book, Personal Digital Assistant (PDA), Smart TV, and ICT devices have.

The network 130 provides a path for transferring data between the cloud streaming server 110 and the terminal devices 120-1,..., 120 -N, and is a network that can be used in the future and a network that can be developed in the future. This is a comprehensive concept. For example, the network 130 is a wired or wireless local area network that provides communication of various information devices within a limited area, a mobile communication network that provides communication between each other and between the mobile and the outside of the mobile, and the communication between the earth station and the earth station using satellites. It may be made of a satellite communication network or a wired or wireless communication network providing a combination of two or more. Meanwhile, the transmission standard of the network 130 is not limited to the existing transmission method standard and may include all transmission method standards to be developed in the future. In addition, in FIG. 1, the network used between the cloud streaming server 110 and the terminal devices 120-1,..., 120 -N is terminal devices 120-1,..., 120 -N. It may be different from the networks used mutually, or may be the same.

FIG. 2 is a block diagram illustrating an example of a cloud streaming server of FIG. 1.

Referring to FIG. 2, the cloud streaming server 110 illustrated in FIG. 1 includes a capture unit 210, a key frame extractor 220, an encoder 230, a sender 240, and a storage 250. Include.

The capture unit 210 captures an execution screen of an application executed for the cloud streaming service. For example, when an application execution request is received by one or more terminal devices connected to the cloud streaming server 110 through a network, the application is executed in the cloud streaming server 110 in response to a request of the terminal device. An execution screen corresponding to an application execution result may be captured to be delivered to the terminal device.

The key frame extracting unit 220 extracts a key frame of the execution screen.

The execution screen may be composed of a plurality of frames, and a plurality of similar frames may exist because the change is not large among the plurality of frames. In this case, in order to perform a still image-based cloud streaming service, all frames must be compressed and provided to a user terminal device using a still image compression technique, and still image compression information for each frame is configured according to the still image compression technique. Needs to be. If there are many similar frames, it may cause a problem to smoothly provide a service due to a large consumption of system resources for composing still image compression information for all frames. Accordingly, system resources may be saved by extracting a key frame among similar frames and compressing the still image compression information generated based on the key frame by applying the same to the remaining similar frames.

In this case, the key frame may be a frame in which the change value of the frame is greater than or equal to a preset reference value in comparison with the previous frame in the execution screen. For example, when about 60 percent of the entire area of a frame changes compared to the previous frame, the frame can be extracted as a key frame. Such preset reference values can be freely set and modified by a developer.

In addition, if the reference value is set too low, too many key frames are extracted, so that the consumption of system resources may be severe. If the reference value is set too high, the extracted key picture may be less so that the image quality of the encoded execution screen may be severe. Therefore, in order to prevent such a problem, it is possible to set the maximum reference value and the minimum reference value and to make modifications within the range.

In this case, the change value of the frame may be calculated in consideration of the change of the pixel value of the execution screen. For example, the change value of all the pixels included in the frame may be calculated, and the change value of the frame may be calculated by determining the degree of change by comparing the pixel value of the previous frame. If it is assumed that there are 10000 pixels constituting the frame and the preset reference value is 60 percent, the frame may be determined as a key frame and extracted if it is changed by 6000 pixels or more compared with the previous frame.

In this case, the key frame may be extracted in consideration of at least one of the input signal of the application and the number of additional colors. For example, since the input signal of the application may be a signal for changing the execution screen of the application, the input signal of the application may be sensed to determine the first frame of the execution screen generated by the input signal as a large key frame. . In addition, when the additional color is reduced by more than a predetermined number as compared with the previous frame, the frame may be determined as a key frame and extracted.

The encoding unit 230 generates still image compression information corresponding to the key frame, and applies a still image compression technique based on the still image compression information to one or more of the remaining frames and key frames except the key frame in the execution screen. To encode a running image. For example, after generating still image compression information for one or a plurality of key frames of the frames constituting the execution screen, the remaining frames are applied to the still image compression technique using the still image compression information that has already been generated. By performing the encoding, the execution screen consisting of the key frame and the remaining frames can be still image encoded.

In this case, a subframe having a change value of a frame less than a predetermined reference value may be extracted from the remaining frames, and the subframe may be compressed using a still image compression technique. For example, since a plurality of key frames may exist in the execution screen, similar frames corresponding to each key frame may exist among the remaining frames. As described above, when a change value of a frame is compared with each key frame, a similar frame having a lower value than a predetermined reference value is extracted as a subframe for the key frame, and the key frame is compressed using a still image compression technique.

In this case, the still image compression information may include one or more of a palette, a color substitution table, and an optimal filter. For example, when performing still image encoding by applying PNG still image compression to still image-based cloud streaming, the compression efficiency is lower compared to video-based cloud streaming, which can cause transmission delays when the bandwidth of the network is limited. There is a problem. Therefore, in order to increase the compression efficiency of the PNG still image compression technique, a palette, a color substitution table, an optimal filter, and the like may be used to reduce the width of colors constituting the image.

In general, the PNG format can express image color information in RGB and Indexed Color formats. The RGB format can use red, green, and blue values for each pixel. However, in the Indexed Color format, a color used to compose an image may be pre-written in a table called a palette, and information about which color on the palette table is used for each pixel may be included. In this case, the RGB format requires 8 bits each for red, green, and blue, and 24 bits are required for each pixel. However, since only 8 bits are required for the Indexed Color format, when converting the RGB format to the Indexed Color format, the data size is 3 Can be reduced to one-third.

In addition, since the indexed color format represents information using 8 bits, only up to 256 pieces of information can be represented. However, since the RGB format can express more colors than the Indexed Color format, the color substitution table can be used to replace the RGB format color with the color included in the Indexed Color format palette. In this case, since the number of colors that can be used is inevitably reduced than that in the RGB format, image quality may be degraded.

In addition, since it is inefficient to treat which color is the information for each pixel in the Indexed Color format as it is, it is possible to apply a structure for arranging data called a filter for each row of pixels. For example, if a row consists of five pixels and all five pixels contain information that says red, the information in pixels is in the form of 'red, red, red, red, red'. It may be more succinct to express it as 'five red' than it does. Therefore, the optimum filter may be applied to each row of the pixel, thereby making the data more concise.

At this time, the subframe may be compressed using a still image compression technique based on still image compression information until the next key frame of the key frame appears. For example, the still image compression information for the first key frame extracted from the execution screen may be configured, and subsequent subframes may be still image encoded using the same. At this time, if the still image encoding of subframes for the first key frame is completed and the second key frame is extracted, the still image compression information is configured again for the second key frame, and the second subframes for the subsequent subframes. Still image encoding may be performed by applying a still image compression method using still image compression information of a key frame.

At this time, the key frame and the still image compression information can be linked and stored in the database. For example, before performing still image encoding, all key frames included in the execution screen may be extracted in advance, and still image compression information for each key frame may be generated and stored in a database. In this case, by interlocking the key frame and the still image compression information, it is possible to easily find and use the stored still image compression information when compressing the key frame and the subframe.

In this case, a still image may be encoded using a paletted portable network graphics (PNG) still image compression technique using still image compression information. Compared to PNG still image compression, palletized PNG still image compression can cause image quality degradation, but can reduce the size of data to one-third, resulting in transmission delays in environments with limited network bandwidth. Can be prevented.

The sending unit 240 transmits a still image encoded execution screen to a user terminal device to perform a still image based cloud streaming service. By completing the still image encoding and transmitting the compressed execution screen to the user's terminal device, the user may feel as if the application is executed in the user's terminal device.

The storage unit 250 stores various information generated in the cloud streaming service process according to the embodiment of the present invention as described above.

According to an embodiment, the storage 250 may be configured independently of the cloud streaming server 110 to support a function for a cloud streaming service. At this time, the storage unit 250 may operate as a separate mass storage, and may include a control function for performing the operation.

In addition, the cloud streaming server 110 configured as described above may be implemented as one or more servers.

Meanwhile, the cloud streaming server 110 may be equipped with a memory to store information in the device. In one embodiment, the memory is a computer readable medium. In one implementation, the memory may be a volatile memory unit, and for other implementations, the memory may be a nonvolatile memory unit. In one embodiment, the storage device is a computer readable medium. In various different implementations, the storage device may include, for example, a hard disk device, an optical disk device, or some other mass storage device.

In addition, the storage unit 250 may store the key frame and the still image compression information in association with the database of the present invention.

3 is a diagram illustrating a key frame and a sub frame according to an embodiment of the present invention.

Referring to FIG. 3, a plurality of frames constituting an execution screen of an application may be divided into key frames 310 and 320 and subframes 310-1, 310-2, 320-1, and 320-N.

In this case, the key frame may be a frame in which the change value of the frame is greater than or equal to a preset reference value in comparison with the previous frame in the execution screen. For example, in the case of the key frame 320, the change value of the frame may be greater than or equal to a preset reference value when compared to the subframe 310-2 corresponding to the previous frame.

As such, the key frames 310 and 320 and the subframes 310-1, 310-2, 320-1, and 320-N corresponding to the key frames 310 and 320 are likely to be sequentially arranged. Accordingly, when extracting the subframes 310-1, 310-2, 320-1, and 320 -N, frames located between the key frames 310 and 320 may be extracted.

Also, when applying a still image compression method using still image compression information on key frames 310 and 320, a subframe may be applied by applying a still image compression method using the same still image compression information until the next key frame appears. It can be compressed. For example, the subframe 310-1 and the subframe 310-2 may be compressed using a still image compression technique using still image compression information on the key frame 310. When the next key frame 320, which is the next key frame, is displayed, the sub image is extracted using the still image compression technique using the still image compression information on the key frame 320 without using the still image compression information on the key frame 310. The frame 320-1 may be compressed. Thereafter, in the same manner as described above, compression may be performed using a still image compression technique using still image compression information of the key frame 320 until the next key frame appears.

4 is an operation flowchart illustrating a cloud streaming service method for saving system resources according to an embodiment of the present invention.

Referring to FIG. 4, the cloud streaming service method for conserving system resources according to an embodiment of the present invention captures an execution screen of an application executed for the cloud streaming service (S410). For example, when an application execution request is received by at least one terminal device connected to the cloud streaming server through a network, the application is executed in the cloud streaming server according to the request of the terminal device, and corresponds to the application execution result. The execution screen may be captured for delivery to the terminal device.

In addition, the cloud streaming service method for saving system resources according to an embodiment of the present invention extracts a key frame of the execution screen (S420).

The execution screen may be composed of a plurality of frames, and a plurality of similar frames may exist because the change is not large among the plurality of frames. In this case, in order to perform a still image-based cloud streaming service, all frames must be compressed and provided to a user terminal device using a still image compression technique, and still image compression information for each frame is configured according to the still image compression technique. Needs to be. If there are many similar frames, it may cause a problem to smoothly provide a service due to a large consumption of system resources for composing still image compression information for all frames. Accordingly, system resources may be saved by extracting a key frame among similar frames and compressing the still image compression information generated based on the key frame by applying the same to the remaining similar frames.

In this case, the key frame may be a frame in which the change value of the frame is greater than or equal to a preset reference value in comparison with the previous frame in the execution screen. For example, when about 60 percent of the entire area of a frame changes compared to the previous frame, the frame can be extracted as a key frame. Such preset reference values can be freely set and modified by a developer.

In addition, if the reference value is set too low, too many key frames are extracted, so that the consumption of system resources may be severe. If the reference value is set too high, the extracted key picture may be less so that the image quality of the encoded execution screen may be severe. Therefore, in order to prevent such a problem, it is possible to set the maximum reference value and the minimum reference value and to make modifications within the range.

In this case, the change value of the frame may be calculated in consideration of the change of the pixel value of the execution screen. For example, the change value of all the pixels included in the frame may be calculated, and the change value of the frame may be calculated by determining the change degree by comparing the pixel value of the previous frame. If it is assumed that there are 10000 pixels constituting the frame and the preset reference value is 60 percent, the frame may be determined as a key frame and extracted if it is changed by 6000 pixels or more compared with the previous frame.

In this case, the key frame may be extracted in consideration of at least one of the input signal of the application and the number of additional colors. For example, since the input signal of the application may be a signal for changing the execution screen of the application, the input signal of the application may be sensed to determine the first frame of the execution screen generated by the input signal as a large key frame. . In addition, when the additional color is reduced by more than a predetermined number as compared with the previous frame, the frame may be determined as a key frame and extracted.

In addition, the cloud streaming service method for saving system resources according to an embodiment of the present invention generates a still image compression information corresponding to the key frame, and at least one of the remaining frames and key frames other than the key frame of the execution screen In operation S430, the still screen is encoded by applying a still image compression technique based on still image compression information. For example, after generating still image compression information for one or a plurality of key frames of the frames constituting the execution screen, the remaining frames are applied to the still image compression technique using the still image compression information that has already been generated. By performing the encoding, the execution screen consisting of the key frame and the remaining frames can be still image encoded.

In this case, a subframe having a change value of a frame less than a predetermined reference value may be extracted from the remaining frames, and the subframe may be compressed using a still image compression technique. For example, since a plurality of key frames may exist in the execution screen, similar frames corresponding to each key frame may exist among the remaining frames. As described above, when a change value of a frame is compared with each key frame, a similar frame having a lower value than a predetermined reference value is extracted as a subframe for the key frame, and the key frame is compressed using a still image compression technique.

In this case, the still image compression information may include one or more of a palette, a color substitution table, and an optimal filter. For example, when performing still image encoding by applying PNG still image compression to still image-based cloud streaming, the compression efficiency is lower compared to video-based cloud streaming, which can cause transmission delays when the bandwidth of the network is limited. There is a problem. Therefore, in order to increase the compression efficiency of the PNG still image compression technique, a palette, a color substitution table, an optimal filter, and the like may be used to reduce the width of colors constituting the image.

In general, the PNG format can express image color information in RGB and Indexed Color formats. The RGB format can use red, green, and blue values for each pixel. However, in the Indexed Color format, a color used to compose an image may be pre-written in a table called a palette, and information about which color on the palette table is used for each pixel may be included. In this case, the RGB format requires 8 bits each for red, green, and blue, and 24 bits are required for each pixel. However, since 8 bits are required for the Indexed Color format, the size of the data is 3 when converting the RGB format to the Indexed Color format. Can be reduced to one-third.

In addition, since the indexed color format represents information using 8 bits, only up to 256 pieces of information can be represented. However, since the RGB format can express more colors than the Indexed Color format, the color substitution table can be used to replace the RGB format color with the color included in the Indexed Color format palette. In this case, since the number of colors that can be used is inevitably reduced than that in the RGB format, image quality may be degraded.

In addition, since it is inefficient to treat which color is the information for each pixel in the Indexed Color format as it is, it is possible to apply a structure for arranging data called a filter for each row of pixels. For example, if a row consists of five pixels and all five pixels contain information that says red, the information in pixels is in the form of 'red, red, red, red, red'. It may be more succinct to express it as 'five red' than it does. Therefore, the optimum filter may be applied to each row of the pixel, thereby making the data more concise.

At this time, the subframe may be compressed using a still image compression technique based on still image compression information until the next key frame of the key frame appears. For example, the still image compression information for the first key frame extracted from the execution screen may be configured, and subsequent subframes may be still image encoded using the same. At this time, if the still image encoding of subframes for the first key frame is completed and the second key frame is extracted, the still image compression information is configured again for the second key frame, and the second subframes for the subsequent subframes. Still image encoding may be performed by applying a still image compression method using still image compression information of a key frame.

At this time, the key frame and the still image compression information can be linked and stored in the database. For example, before performing still image encoding, all key frames included in the execution screen may be extracted in advance, and still image compression information for each key frame may be generated and stored in a database. In this case, by interlocking the key frame and the still image compression information, it is possible to easily find and use the stored still image compression information when compressing the key frame and the subframe.

In this case, a still image may be encoded using a paletted portable network graphics (PNG) still image compression technique using still image compression information. Compared to PNG still image compression, palletized PNG still image compression can cause image quality degradation, but can reduce the size of data to one-third, resulting in transmission delays in environments with limited network bandwidth. Can be prevented.

In addition, the cloud streaming service method for saving system resources according to an embodiment of the present invention transmits a still image encoded execution screen to the user's terminal device to perform a still image-based cloud streaming service (S440). By completing the still image encoding and transmitting the compressed execution screen to the user's terminal device, the user may feel as if the application is executed in the user's terminal device.

5 is an operation flowchart showing in detail a cloud streaming service method for saving system resources according to an embodiment of the present invention.

Referring to FIG. 5, the cloud streaming service method for saving system resources according to an embodiment of the present invention first captures an execution screen of an application executed for a cloud streaming service (S510).

Thereafter, a change value of the frame is calculated by comparing the previous frame with the current frame of the frames constituting the execution screen to extract the key frame (S520).

Thereafter, it is determined whether the change value of the frame is equal to or greater than a predetermined reference value (S525).

If the determination result in step S525 is equal to or greater than the preset reference value, the current frame is extracted as a key frame (S530).

If the determination result of the step (S525) is less than the predetermined reference value, it is determined that the current frame as the remaining frames other than the key frame (S540).

Thereafter, still image compression information on the extracted key frame is generated (S550). In this case, the still image compression information may include one or more of a palette, a color substitution table, and an optimal filter.

Thereafter, the frame change value is calculated by comparing the key frame with the remaining frames (S560).

Thereafter, it is determined whether the frame change value of the remaining frames compared with the key frame is less than the predetermined reference value (S565).

If the determination result in step S565 is less than the predetermined reference value, the corresponding remaining frame is extracted as a subframe of the key frame (S570).

If the determination result of step S565 is equal to or greater than the preset reference value, it may be determined again whether the corresponding remaining frame is a key frame, and may be divided into one of a key frame and a subframe of another key frame.

Thereafter, the execution screen consisting of the key frame and the sub frame is encoded in the still image (S580). For example, a still image encoding may be performed by compressing a subframe using a still image compression technique using still image compression information of a key frame.

Thereafter, the execution screen on which the still image encoding is completed is transmitted to the user's terminal device to perform a cloud streaming service based on the still image (S590).

6 is a block diagram showing a cloud streaming service system according to another embodiment of the present invention.

Referring to FIG. 6, a cloud streaming service system according to another exemplary embodiment of the present invention may include a web application server 605, a cloud streaming server 610, terminal devices 620-1,..., 620 -N, and a network. 630.

The web application server 605 is a server that receives and processes requests from the terminal devices 620-1,. Rather than processing all requests received from terminal devices 620-1, ..., 620-N, the web application server 605 structurally separates and processes the functions of the web application server 605 through web containers. Since the number of service requests from the terminal devices 620-1,..., And 620 -N increases, the method of serving using the web application server 605 may be more effective. For example, BEA's WEB LOGIC, IBM's Web Spere, T-max's JEUS, Tomcat, RedHot's Jboss, etc. may correspond to the web application server 605.

The application server 605 may transmit the application code corresponding to the application result screen to the cloud streaming server 605 based on the service request received from the terminal devices 620-1, ..., 620-N. .

The cloud streaming server 610 receives a first code corresponding to the application result screen from the web application server 605.

In addition, the cloud streaming server 610 may generate the capture image information by using the image region property information included in the first code.

In addition, the cloud streaming server 610 may generate animation information using the animation code included in the first code.

In addition, the cloud streaming server 610 may convert the first code into a second code including captured image information and animation information. In this case, the second code may include animation information corresponding to at least one or more of an animation type, an animation application time, an animation repetition number, a start coordinate, an end coordinate, a start size, and an end size. At this time, the second code may not include the animation code.

In addition, the cloud streaming server 610 generates a captured image using the image region attribute information included in the first code. In this case, the capture image may be generated by rendering the input information corresponding to the image region attribute information included in the first code. In this case, only a part of the application result screen may be rendered to generate a captured image.

In addition, the cloud streaming server 610 still image encodes the captured image using a still image compression technique. At this time, the captured image may be still image encoded using a still image compression technique corresponding to any one of portable network graphics (PNG), palletized portable network graphics (PNG), and joint photography experts group (JPEG).

In addition, the cloud streaming server 610 converts the still image-encoded captured image and the first code to generate the application result screen in the terminal devices 620-1,. The second code generated to be included is transmitted to the user terminal to perform a still image based cloud streaming service.

The terminal devices 620-1,..., 620 -N receive an application execution result screen corresponding to the cloud streaming service from the cloud streaming server 610 and provide the result to the user.

The terminal devices 620-1,..., 620 -N are devices connected to a communication network to execute an application based on a cloud computing system, and are not limited to mobile communication terminals. It may be a variety of terminals, such as a wired terminal, a fixed terminal and an IP (Internet Protocol) terminal. In addition, the terminal devices 620-1, ..., 620-N are mobile phones, portable multimedia players (PMPs), mobile internet devices (MIDs), smart phones, desktops, and tablet computers, respectively. Number of mobile terminals with various mobile communication specifications such as Tablet PC, Note book, Net Book, Personal Digital Assistant (PDA), Smart TV, and ICT devices have.

The network 630 provides a path for transferring data between the cloud streaming server 610 and the terminal devices 620-1,. This is a comprehensive concept. For example, the network 630 may be a wired / wireless local area network that provides communication of various information devices within a limited area, a mobile communication network that provides communication between mobile devices, and a mobile device and an external device. It may be made of a satellite communication network or a wired or wireless communication network providing a combination of two or more. Meanwhile, the transmission method standard of the network 630 is not limited to the existing transmission method standard, and may include all transmission method standards to be developed in the future. 6, the network used between the cloud streaming server 610 and the terminal devices 620-1,..., 620 -N is terminal devices 620-1,..., 620 -N. It may be different from the networks used mutually, or may be the same.

FIG. 7 is a block diagram illustrating an example of a cloud streaming server of FIG. 6.

Referring to FIG. 7, the cloud streaming server illustrated in FIG. 6 includes a code receiver 710, a capture image information generator 720, an animation information generator 730, a code converter 740, and a capture unit 750. , An encoding unit 760, a sending unit 770, and a storage unit 780.

The code receiving unit 710 receives a first code corresponding to the application result screen from the web application server. The first code may include animation information about animation effects applied when an application is executed and image region property information on images to which animation effects are applied. It can also be written in the same way that web application developers used. For example, the first code may be written using a library such as jQuery that is widely used for animation.

The capture image information generator 720 generates capture image information by using image region attribute information included in the first code. For example, the image area attribute information may be coordinate information for the image to be captured.

The animation information generator 730 generates animation information using the animation code included in the first code. The animation code included in the second code is a code for executing an animation. When executing the corresponding code, an unnecessary capture may occur. Therefore, the animation information can be generated using the information that can be checked and extracted from the content of the animation code.

The code converter 740 converts the first code into a second code including captured image information and animation information. Therefore, when the second code is checked, detailed information on the capture region and animation may be obtained.

In this case, the second code may include animation information corresponding to at least one or more of an animation type, an animation application time, an animation repetition number, a start coordinate, an end coordinate, a start size, and an end size. For example, in the second code, the animation type is' effect type ', the animation application time is' duration', the animation repetition number is' isRepeat ', the start coordinate is' start X, start Y', the end coordinate is' end X, end Y ', the start size may be indicated as' start W, start H' and the end size as' end W, end H '.

At this time, the second code may not include the animation code.

The capturer 750 generates a captured image by using image region attribute information included in the first code. In this case, the reading may be directly performed without performing a process of capturing an image corresponding to the image region attribute information. For example, when rendering an application result screen and capturing a portion corresponding to the image area attribute information among the rendered screens, it may be inefficient because the resources of the server are used to perform rendering or capturing. Therefore, an image corresponding to the image region attribute information may be read and generated among the information received from the web application server.

In this case, the capture image may be generated by rendering the input information corresponding to the image region attribute information included in the first code. For example, the captured image may be generated by rendering only a portion of the first code corresponding to the captured image using the image region attribute information.

In this case, only a part of the application result screen may be rendered to generate a captured image. For example, in a general rendering operation, the entire portion of the application result screen may be rendered, and an operation of comparing the differences between the regions may be performed to detect a portion to be captured. However, since the resources of the cloud streaming server 610 are consumed by performing these various processes, it may be difficult to simultaneously process more service requests. Therefore, the capture image may be generated by rendering only a portion of the entire application result screen including the captured image.

The encoder 760 encodes the captured image by using a still image compression technique.

At this time, the captured image may be still image encoded using a still image compression technique corresponding to any one of portable network graphics (PNG), palletized portable network graphics (PNG), and joint photography experts group (JPEG).

In PNG still image compression, the image quality is good when encoding, but when the bandwidth of the transmission network is low due to the large data size, the transmission speed may be reduced.

Palletized PNG still image compression reduces the data size of the image during encoding, which guarantees transmission speed, but degrades image quality due to the 8-bit color representation.

The JPEG still image compression technique has a high compression efficiency and can greatly reduce the amount of data transmitted during encoding. However, the high compression efficiency can cause a large system load when encoding and decoding.

The sending unit 770 converts a still image encoded capture image and a first code to generate an application result screen in the user terminal, and transmits a second code generated to include animation information to the user terminal to generate an application result screen. Perform cloud streaming service. For example, the cloud streaming server 610 may completely generate and stream the application result screen, but the load generated by the cloud streaming server 610 by transmitting the user terminal to generate the application result screen in the same manner as described above. Can be significantly reduced. As such, when the load of the cloud streaming server 610 is reduced, the number of services that can be simultaneously processed by the cloud streaming server 610 increases, so that more users can be provided with the service at the same time.

8 is a diagram illustrating performing a still image-based cloud streaming service according to an embodiment of the present invention.

Referring to FIG. 8, a process of performing a still image-based cloud streaming service according to an embodiment of the present disclosure may be classified into a process performed by the cloud streaming server 800 and the user terminal 805.

The cloud streaming server 800 may perform an application code reception 820 corresponding to the application result screen 810 generated according to a user request from the application server. In this case, the application code may include image area attribute information, animation code, and the like as the first code.

Thereafter, the captured image may be generated using the image region attribute information included in the application code, and the generated captured image may be encoded 830. In this case, the captured image may be acquired by reading immediately according to the type of the image included in the image region attribute information or by performing minimal rendering using the image region attribute information. For example, in the case of an image of PNG type, encoding may be performed by reading immediately.

In addition, the capture image information and the animation information may be generated using the image region attribute information and the application code included in the application code, respectively.

Thereafter, the application code may be converted to generate a conversion code 840 including captured image information and animation information. In this case, the conversion code is a second code and may include information of an animation rather than an animation code.

The cloud streaming server 800 may send the encoded capture image 830 and the second code, which is a conversion code, to the user terminal 805 together 850. In this case, the capture image and the conversion code may be included in one message and transmitted, or the message for each capture image and the conversion code may be generated and transmitted.

The user terminal 805 may generate an application result screen using the captured image and the conversion code received from the cloud streaming server 800. That is, the animation may be applied to the captured image based on the animation information and the captured image information included in the conversion code (860). At this time, the animation information includes information such as animation type, animation application time, animation repetition count, start coordinates, end coordinates, start size and end size, so that the animation results can be applied to the captured image accurately and easily. Can be generated.

The user terminal 805 may render an image of the application result screen generated in this way and output the image to the user.

9 illustrates a first code and a second code according to an embodiment of the present invention.

9, a first code 910 according to an embodiment of the present invention includes image region property information 911 and an animation code 912, and a second code 920 includes captured image information 921. ) And animation information 922.

The first code 910 may be an application code corresponding to the application result screen received from the web application server. Accordingly, the image region property information 911 may be information about an animated portion of the application result screen, and the animation code 912 is a code for animation effect applied to the portion corresponding to the image region property information 911. Can be.

The second code 920 may include captured image information 921 generated using the image region property information 911 and animation information 922 generated using the animation code 912. Accordingly, the second code 920 may be transmitted to the user terminal so that the user terminal may generate an application result screen corresponding to the first code 910.

10 is a diagram illustrating code conversion according to an embodiment of the present invention.

Referring to FIG. 10, it can be seen that the first code 1010 is converted into the form of the second code 1020.

In this case, the first code 1010 is written using a library such as jQuery that is used for animation, and the attributes of the area to be captured described in the first and second lines of the first code 1010, and the fourth and fifth. It contains the animation code listed in the first line. That is, when the first code 1010 is interpreted, it may refer to applying a SlideUp animation to 'img1.png'. Using the above information, the first code 1010 may be converted into the second code 1020 to include captured image information and animation information.

For example, if the contents included in the seventh through ninth lines of the second code 1020 are checked, the animation type is' SlideUp ', the application time is' 8000', the number of repetitions is' 0 ', and the start coordinate is' 332,800 ', the start size is' 551, 191', the end coordinate is' 332, 0 ', the end size is' 551, 191'. As such, by including the coordinate information of the captured image and information such as the type, the application time, and the number of repetitions of the animation, the second terminal 1010 may be generated when the application result screen including the animation is generated in the user terminal. You can convert the code so that

In this case, the captured image to be delivered to the user terminal together with the second code 1020 may be directly extracted from the first code 1010. For example, 'img1.png' may be extracted from the first code 1010 and stored as a captured image, and the captured image may be delivered to the user terminal together with the generated second code 1020.

11 is a diagram illustrating code conversion according to another embodiment of the present invention.

Referring to FIG. 11, the first code 1110 may include a code area of test_1 including img1.png and img2.png, a code area of test_2 including img3.png and img4.png, and img5.png and img6.png. It can be seen that it is composed of a code region of test_3 that includes, and the animation corresponding to fadeout is applied to the code region of test_1 as in the 23rd and 24th lines of the first code 1110.

When the first code 1110 is converted to the second code 1120, the first code 1110 may be generated as the second code 1120 using only the test_1 code area including img1.png and img2.png corresponding to the captured image. Can be.

At this time, only the 'div id = "test_1"' can be directly made an image to generate a captured image. By generating the captured image in this way, it is possible to skip the process of capturing the application result screen or comparing the captured screen with other regions, thereby saving resources of the cloud streaming server.

In this case, the captured image to be transmitted to the user terminal together with the second code 1120 may be obtained by storing a result of rendering the partial code of the first code 1110 as an image. For example, the first code 1110 may render lines 5 through 8 to obtain capture images corresponding to 'img1.png' and 'img2.png', and obtain the captured images. 2 codes 1120 together with the user terminal can be delivered.

12 is a flowchart illustrating an image cloud streaming service method using an application code according to an embodiment of the present invention.

Referring to FIG. 12, the image cloud streaming service method using an application code according to an embodiment of the present invention receives a first code corresponding to an application result screen from a web application server (S1210). The first code may include animation information about animation effects applied when an application is executed and image region property information on images to which animation effects are applied. It can also be written in the same way that web application developers used. For example, the first code may be written using a library such as jQuery that is widely used for animation.

In addition, the image cloud streaming service method using the application code according to an embodiment of the present invention generates a captured image using the image region attribute information included in the first code (S1220). In this case, the reading may be directly performed without performing a process of capturing an image corresponding to the image region attribute information. For example, when rendering an application result screen and capturing a portion corresponding to the image area attribute information among the rendered screens, it may be inefficient because the resources of the server are used to perform rendering or capturing. Therefore, an image corresponding to the image region attribute information may be read and generated among the information received from the web application server.

In this case, the capture image may be generated by rendering the input information corresponding to the image region attribute information included in the first code. For example, the captured image may be generated by rendering only a portion of the first code corresponding to the captured image using the image region attribute information.

In this case, only a part of the application result screen may be rendered to generate a captured image. For example, in a general rendering operation, the entire portion of the application result screen may be rendered, and an operation of comparing the differences between the regions may be performed to detect a portion to be captured. However, since the resources of the cloud streaming server are consumed by performing these various processes, it may be difficult to process more service requests at the same time. Therefore, the capture image may be generated by rendering only a portion of the entire application result screen including the captured image.

In addition, the image cloud streaming service method using the application code according to an embodiment of the present invention encodes the captured image still image using a still image compression technique (S1230).

At this time, the captured image may be still image encoded using a still image compression technique corresponding to any one of portable network graphics (PNG), palletized portable network graphics (PNG), and joint photography experts group (JPEG).

In PNG still image compression, the image quality is good when encoding, but when the bandwidth of the transmission network is low due to the large data size, the transmission speed may be reduced.

Palletized PNG still image compression reduces the data size of the image during encoding, which guarantees transmission speed, but degrades image quality due to the 8-bit color representation.

The JPEG still image compression technique has a high compression efficiency and can greatly reduce the amount of data transmitted during encoding. However, the high compression efficiency can cause a large system load when encoding and decoding.

In addition, the image cloud streaming service method using the application code according to an embodiment of the present invention is generated to include the animation information by converting the still image-encoded capture image and the first code to generate the application result screen in the user terminal The second code is transmitted to the user terminal to perform a cloud streaming service based on a still image (S1240). For example, a cloud streaming server can completely generate and stream an application result screen, but the load generated by the cloud streaming server can be significantly reduced by transmitting the application result screen to the user terminal in the same manner as described above. have. As the load of the cloud streaming server is reduced in this way, the number of services that can be simultaneously processed by the cloud streaming server increases, so that more users can be provided with the service at the same time.

In this case, the second code may include animation information corresponding to at least one or more of an animation type, an animation application time, an animation repetition number, a start coordinate, an end coordinate, a start size, and an end size. For example, in the second code, the animation type is' effect type ', the animation application time is' duration', the animation repetition number is' isRepeat ', the start coordinate is' start X, start Y', the end coordinate is' end X, end Y ', the start size may be indicated as' start W, start H' and the end size as' end W, end H '.

At this time, the second code may not include the animation code.

In addition, although not shown in FIG. 12, the image cloud streaming service method using an application code according to an embodiment of the present invention generates capture image information by using image region attribute information included in the first code. For example, the image area attribute information may be coordinate information for the image to be captured.

In addition, although not shown in Figure 12, the image cloud streaming service method using the application code according to an embodiment of the present invention generates animation information using the animation code included in the first code. The animation code included in the second code is a code for executing an animation. When executing the corresponding code, an unnecessary capture may occur. Therefore, the animation information can be generated using the information that can be checked and extracted from the content of the animation code.

In addition, although not shown in FIG. 12, the image cloud streaming service method using the application code according to an embodiment of the present invention converts the first code into a second code including captured image information and animation information. Therefore, when the second code is checked, detailed information on the capture region and animation may be obtained.

13 is a flowchart illustrating a code conversion process according to an embodiment of the present invention.

Referring to FIG. 13, in the code conversion process according to an embodiment of the present invention, capture image information is generated using image region attribute information included in a first code received from a web application server (S1310).

In this case, the first code may include an animation code for the animation effect applied when the application is executed and image region property information for the images to which the animation effect is applied. In addition, the first code may be written in a manner conventionally used by web application developers. For example, the first code may be written using a library such as jQuery that is widely used for animation.

In addition, the code conversion process according to an embodiment of the present invention generates animation information using the animation code included in the first code (S1320). In this case, the animation code included in the first code is a code for executing an animation, and when executing the corresponding code, an unnecessary capture may occur. Therefore, animation information for transmission to the user terminal can be generated using the content of the animation code.

In addition, the code conversion process according to an embodiment of the present invention converts the first code into a second code including captured image information and animation information (S1330). Therefore, the user terminal may generate an application screen to which the captured image is animated using the second code.

In this case, the second code may include animation information corresponding to at least one or more of an animation type, an animation application time, an animation repetition number, a start coordinate, an end coordinate, a start size, and an end size. For example, the animation type is 'effect type', the animation duration is 'duration', the animation repeat count is 'isRepeat', the start coordinate is 'start X, start Y', the end coordinate is 'end X, end Y', The start size may be described as an identifier such as 'start W, start H' and an end size such as 'end W and end H' to indicate animation information by assigning a value to each identifier. Also, the second code may not include the animation code.

The cloud streaming service method for saving system resources according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and any type of hardware device specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions may include high-level language code that can be executed by a computer using an interpreter as well as machine code such as produced by a compiler. Such hardware devices may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the cloud streaming service system according to the present invention, the cloud streaming service method for saving system resources, and the apparatus therefor are not limited to the configuration and method of the embodiments described as described above. The embodiments may be configured by selectively combining all or part of the embodiments so that various modifications can be made.

According to the present invention, the execution screen of an application executed for the cloud streaming service is captured, a key frame is extracted from the execution screen, still image compression information corresponding to the key frame is generated, and the remaining frames except the key frame among the execution screens. A still image based cloud by applying a still image compression technique based on still image compression information to one or more of the field and key frame, and transmitting the still image encoded execution screen to a user's terminal device. Streaming service can be performed. Furthermore, by saving system resources for generating still image compression information for subframes of a key frame, the cloud streaming server can provide services to more users at the same time.

Also, according to the present invention, a first code corresponding to an application result screen is received from a web application server, a captured image is generated using image region attribute information included in the first code, and captured using a still image compression technique. The still image-based cloud by encoding the image and converting the still image-encoded captured image and the first code to generate the application result screen on the user terminal, and transmitting the generated second code to include the animation information to the user terminal. Streaming service can be performed. Furthermore, even if web application developers write application code of a desired type in a conventional manner rather than a new type of code, a cloud streaming service for applying an animation effect to a user terminal may provide a convenience of a service provider. have.

Claims (20)

1. A capture unit that captures an execution screen of an application executed for a cloud streaming service;

   A key frame extracting unit extracting a key frame of the execution screen;

   Generating still image compression information corresponding to the key frame, and applying a still image compression technique based on the still image compression information to one or more of the remaining frames other than the key frame and the key frame among the execution screens An encoding unit for encoding a still image of the execution screen; And

   Sending unit for transmitting the still image encoded execution screen to the user's terminal device to perform a still image-based cloud streaming service

   Cloud streaming server comprising a.
2. The method according to claim 1,

   The encoding unit

   And extracting a subframe having a change value of a frame less than a predetermined reference value among the remaining frames, and compressing the subframe using the still image compression technique.
3. The method according to claim 2,

   The key frame is

   Cloud streaming server, characterized in that the change value of the frame compared to the previous frame of the execution screen is a frame of more than the predetermined reference value.
4. The method according to claim 3,

   The still image compression information is

   A cloud streaming server comprising at least one of a palette, a color substitution table and an optimal filter.
5. The method according to claim 4,

   The encoding unit

   And compressing the subframe by using the still image compression technique based on the still image compression information until the next key frame of the key frame appears.
6. The method according to claim 5,

   The encoding unit

   And storing the key frame and the still image compression information in a database.
7. The method according to claim 3,

   The key frame extracting unit

   And a change value of the frame in consideration of the change in the pixel value of the execution screen.
8. The method according to claim 7,

   The key frame extracting unit

   And extracting the key frame in consideration of at least one of the input signal of the application and the number of additional colors.
9. The method according to claim 1,

   The encoding unit

   And a still image encoding the execution screen using a paletted portable network graphics (PNG) still image compression technique using the still image compression information.
10. A code receiving unit which receives a first code corresponding to an application result screen from a web application server;

    A capture unit to generate a captured image by using image area attribute information included in the first code;

    An encoding unit for still image encoding the captured image using a still image compression technique; And

    Still image-based cloud streaming by transmitting the still image-encoded capture image and the second code generated by converting the first code to include the animation information so as to generate the application result screen in the user terminal. Sending part performing service

    Cloud streaming server comprising a.
11. The method according to claim 10,

    The capture unit

    And generating the captured image by performing rendering on input information corresponding to the image region attribute information included in the first code.
12. The method according to claim 11,

    The cloud streaming server

    Capture image information generation unit for generating capture image information by using the image area attribute information included in the first code.

    An animation information generator configured to generate the animation information by using the animation code included in the first code; And

    A code converter for converting the first code into the second code including the captured image information and animation information

    Cloud streaming server further comprising.
13. The method according to claim 12,

    The capture unit

    Cloud capture server, characterized in that to generate the captured image by performing the rendering only on a portion of the application result screen.
14. The method according to claim 12,

    The second code is

    And the animation information corresponding to at least one of an animation type, an animation application time, an animation repetition number, a start coordinate, an end coordinate, a start size, and an end size.
15. The method according to claim 14,

    The second code is

    Cloud streaming server, characterized in that it does not include the animation code.
16. The method according to claim 10,

    The encoding unit

    Cloud streaming characterized by still image encoding of the captured image using a still image compression technique corresponding to any one of portable network graphics (PNG), palletized portable network graphics (PNG) and joint photography experts group (JPEG) server.
17. Capturing an execution screen of an application executed for the cloud streaming service;

    Extracting a key frame from the execution screen;

    Generating still image compression information corresponding to the key frame, and applying a still image compression technique based on the still image compression information to one or more of the remaining frames other than the key frame and the key frame among the execution screens Encoding a still image of the execution screen; And

    Transmitting the still image encoded execution screen to a user's terminal device to perform a still image based cloud streaming service

    Cloud streaming service method for saving system resources comprising a.
18. The method according to claim 17,

    The encoding step

    Extracting a subframe in which the change value of the frame is less than a predetermined reference value, compared to the key frame among the remaining frames;

    And compressing the subframe using the still image compression technique.
19. Receiving a first code corresponding to an application result screen from a web application server;

    Generating a captured image by using image region attribute information included in the first code;

    Still image encoding the captured image using a still image compression technique; And

    The still image-based cloud streaming by converting the still image-encoded capture image and the first code so as to generate the application result screen in the user terminal and the second code generated to include the animation information to the user terminal Steps to Perform a Service

    Image cloud streaming service method using an application code comprising a.
20. The method according to claim 19,

    Generating the captured image

    The image cloud streaming service method using an application code, characterized in that for generating the captured image by performing rendering on the input information corresponding to the image area attribute information included in the first code.

Images