KR102398976B1 - System for cloud streaming service, method of image cloud streaming service using simultaneous encoding and apparatus for the same - Google Patents

Abstract

A cloud streaming service system, an image cloud streaming service method using simultaneous encoding, and an apparatus therefor are disclosed. The changed image is captured by comparing the frames of the application execution screen according to the user's request, and the changed image is encoded as a still image in high and low quality at the same time. It is possible to perform image-based cloud streaming service by determining whether to stop encoding still images, and transmitting a still image-encoded image of either high or low quality to the terminal. It is possible to provide an image-based cloud streaming service with guaranteed image quality and speed.

Description

Cloud streaming service system, image cloud streaming service method using simultaneous encoding, and apparatus therefor

The present invention relates to a technology for providing an image cloud streaming service by performing encoding at the same time in low and high quality, in particular, encoding an image to be delivered to a user's terminal at the same time in low and high quality, and high quality according to the number of colors of the image It relates to a cloud streaming service system that can provide a service by providing a service by determining whether to stop encoding, a cloud streaming service system that can provide fast service with improved image quality, an image cloud streaming service method using simultaneous encoding, and an apparatus therefor.

The rapid development of the Internet has resulted in a rapid increase in individual communication speed, and this communication speed improvement is like downloading or uploading large amounts of data by accessing a computer located at a remote location, or using a remote computer control program as if it were a remote computer. It provides an environment where you can use a remote computer as if you were logged in locally.

In addition, as applications driven in a mobile communication terminal such as a smart phone are developed in various ways, virtualization technologies for driving applications requiring high performance in a user terminal with relatively low performance have been widely proposed.

Among them, based on screen virtualization, the application is run on the server, the driving screen is compressed through video encoding and transmitted to the client, and the client plays the transmitted video to have the same effect as if the application is running on its own terminal. of cloud streaming services are in the spotlight.

In such a cloud streaming service, a video codec-based cloud streaming technique was basically applied. However, even when a static screen such as a menu display is serviced, the entire screen is unnecessarily captured and the video codec is used, which is inefficient as a whole system.

Therefore, an image-based cloud streaming service technology that can provide an image by capturing only the changed part of the static image and controlling the still image encoding performed at the same time for each image quality on the captured image is urgently emerging. .

Korean Patent Laid-Open Patent No. 2008-0053122, registered on June 12, 2008 (Title: Apparatus for adaptive transmission of hierarchically coded content and method therefor)

An object of the present invention is to reduce the amount of load generated during an image-based cloud streaming service by controlling the encoding process according to the quality of an image to be provided to a user.

Another object of the present invention is to improve the speed of providing an image-based cloud streaming service by performing batch still image encoding on images of which image quality is below a certain level to provide images.

Another object of the present invention is to provide an image-based cloud streaming service in which image quality is guaranteed to a user by performing still image encoding using a high-definition encoding method according to the image quality to be provided to the user.

Cloud streaming server according to the present invention for achieving the above object, the capture unit for capturing the changed image by comparing the frames corresponding to the application execution screen received in response to a user request; an encoding unit that simultaneously encodes the changed image in two encoding methods corresponding to high and low picture quality, respectively; an encoding control unit that checks the number of colors of the changed image while encoding the still image, and determines whether to stop encoding of the still image corresponding to the high quality based on the number of colors; and a sending unit for performing an image-based cloud streaming service by transmitting the changed image, which is still image-encoded in one of the high and low quality, to the terminal in order to display the application execution screen in the user's terminal.

In this case, when encoding of the still image corresponding to the high quality is performed without interruption, the sending unit may transmit the changed image encoded with the still image in the high quality to the terminal.

In this case, the encoding unit may simultaneously encode the still image using any one of the lossyPNG encoding method and the PNG32bit encoding method corresponding to the high quality and the palette PNG encoding method corresponding to the low quality.

In this case, when the number of colors is less than or equal to a preset reference number of colors, the encoding control unit may stop encoding of the still image corresponding to the high quality using a high quality encoding stop message.

In this case, when encoding of the still image corresponding to the high quality is stopped, the sending unit may transmit the converted image encoded with the still image in the low quality to the terminal.

In this case, the capture unit may capture the changed image by comparing the current frame and the previous frame among the frames.

At this time, the cloud streaming server compares the frames and performs a video codec-based cloud streaming service for a section with a lot of change, and performs the image-based cloud streaming service for a section with a small change through the image capture. .

In addition, the image cloud streaming service method using the simultaneous encoding according to the present invention, capturing the changed image by comparing the frames corresponding to the application execution screen received in response to a user request; encoding a still image of the changed image using two encoding methods corresponding to high and low quality, respectively; checking the number of colors of the changed image while performing the encoding of the still image, and determining whether to stop encoding the still image corresponding to the high quality based on the number of colors; And in order to display the application execution screen on the user's terminal, the image-based cloud streaming service is performed by transmitting the changed image, which is still image-encoded in one of the high and low quality, to the terminal.

In this case, in the performing step, when encoding of the still image corresponding to the high quality is performed without interruption, the changed image encoded with the still image in the high quality may be transmitted to the terminal.

In this case, in the step of encoding the still image, either one of the lossyPNG encoding method and the PNG32bit encoding method corresponding to the high quality and the palette PNG encoding method corresponding to the low quality may be simultaneously performed.

At this time, the step of determining whether to stop includes generating a high-definition encoding stop message when the number of colors is less than or equal to a preset reference number of colors, and transmitting the high-definition encoding stop message to the encoder end to provide stills corresponding to the high quality Image encoding can be stopped.

In this case, in the performing step, when encoding of the still image corresponding to the high quality is stopped, the converted image encoded with the still image in the low quality may be transmitted to the terminal.

In this case, the capturing may include capturing the changed image by comparing a current frame with a previous frame among the frames.

In this case, the image cloud streaming service method compares the frames and performs a video codec-based cloud streaming service for a section with a lot of change, and performs the image-based cloud streaming service for a section with a small change through the image capture. can

According to the present invention, by controlling the encoding process according to the quality of the image to be provided to the user, it is possible to reduce the load generated during the image-based cloud streaming service.

In addition, the present invention can improve the speed of providing an image-based cloud streaming service by providing images by performing batch still image encoding on images of which image quality is below a certain level.

In addition, the present invention can provide an image-based cloud streaming service with guaranteed image quality to the user by performing still image encoding using a high-definition encoding method according to the image quality to be provided to the user.

In addition, since the present invention renders and displays only the changed image of the frame in the user terminal, it is possible to provide a cloud streaming service smoothly even if the performance of the user terminal is low.

1 is a block diagram illustrating a cloud streaming service system according to an embodiment of the present invention.
2 is a block diagram showing an example of the cloud streaming server shown in FIG.
3 is a diagram illustrating an image-based cloud streaming service process according to the present invention.
4 is a diagram illustrating a process of detecting an image to be captured by comparing frames according to the present invention.
5 is a diagram illustrating a method of including color information in a pixel according to a PNG32-bit method.
6 is a diagram illustrating a method of including color information in a pixel according to the palette PNG method.
7 is a diagram illustrating an example of a color index generated in the palette PNG method.
8 is an operation flowchart illustrating an image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention.
9 is a detailed operation flowchart illustrating an image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention.
10 is a diagram illustrating an image cloud streaming process using simultaneous encoding according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, detailed descriptions of well-known functions or configurations that may obscure the gist of the present invention in the following description and accompanying drawings will be omitted. Also, it should be noted that, throughout the drawings, the same components are denoted by the same reference numerals as much as possible. The embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer description.

The terms or words used in the present specification and claims described below should not be construed as being limited to their ordinary or dictionary meanings, and the inventor is appropriate as a concept of terms for describing his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined in Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all the technical spirit of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations. In addition, terms such as 1st, 2nd, etc. are used to describe various components, and are used only for the purpose of distinguishing one component from other components, and are not used to limit the components.

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

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

The cloud streaming server 110 captures the changed image by comparing frames corresponding to the application execution screen received according to the user's request. In this case, the changed image may be captured by comparing the current frame with the previous frame among the frames.

In addition, the cloud streaming server 110 simultaneously encodes the changed image in two encoding methods corresponding to high quality and low quality, respectively. In this case, it is possible to simultaneously encode still images by using any one of the lossyPNG encoding method and the PNG32bit encoding method corresponding to the high quality and the palette PNG encoding method corresponding to the low quality. In this case, the encoding method corresponding to the high quality may correspond to any one of the lossyPNG encoding method and the PNG32bit encoding method.

In addition, the cloud streaming server 110 checks the number of colors of the changed image while encoding the still image, and determines whether to stop encoding the still image corresponding to the high quality based on the number of colors. In this case, when the number of colors is less than or equal to the preset reference number of colors, encoding of still images corresponding to high quality may be stopped using a high quality encoding stop message.

In addition, the cloud streaming server 110 is a terminal device 120-1 ~ 120-N of the user's terminal device (120-1 ~ 120-N) to display the application execution screen, a still image encoded in any one of high quality and low quality. 120-N) to perform image-based cloud streaming service. In this case, when encoding of the still image corresponding to the high quality is performed without interruption, the changed image encoded with the still image in the high quality may be transmitted to the terminal devices 120 - 1 to 120 -N. In this case, when encoding of the still image corresponding to the high quality is stopped, the changed image encoded with the still image in the low quality may be transmitted to the terminal devices 120 - 1 to 120 -N.

In addition, the cloud streaming server 110 compares frames corresponding to the application execution screen received according to the user's request, and performs a video codec-based cloud streaming service for a section with a large change, and a section with a small change through image capture. An image-based cloud streaming service can be performed.

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

In addition, each of the terminal devices 120-1 to 120-N is a device that is connected to a communication network and can execute an application based on a cloud computing system, and is not limited to a mobile communication terminal, and all information and communication devices, multimedia terminals, and wired terminals. , may be a variety of terminals, such as a fixed terminal and IP (Internet Protocol) terminal. In addition, each of the terminal devices 120-1 to 120-N includes a mobile phone, a Portable Multimedia Played (PMP), a Mobile Internet Device (MID), a smart phone, a desktop, a tablet PC, It may be a mobile terminal having various mobile communication specifications, such as a notebook (notebook), a netbook (Net Book), a personal digital assistant (PDA), a smart TV, and an information communication device.

In addition, the terminal devices 120-1 to 120-N receive various information such as number and character information, and are input in relation to setting various functions and controlling functions of the terminal devices 120-1 to 120-N. A signal may be transmitted to the control unit through the input unit. In addition, the input unit of the terminal devices 120-1 to 120-N may include at least one of a keypad and a touchpad that generate an input signal according to a user's touch or manipulation. At this time, the input unit of the terminal devices 120-1 to 120-N is configured in the form of one touch panel (or touch screen) together with the display unit of the terminal devices 120-1 to 120-N. Input and display functions can be performed at the same time. In addition, as input units of the terminal devices 120-1 to 120-N, all types of input means that may be developed in the future may be used in addition to input devices such as a keyboard, a keypad, a mouse, and a joystick. In particular, the input unit of the terminal devices 120-1 to 120-N according to the present invention can transmit an input signal for uploading or downloading content based on cloud computing to the control unit of the terminal devices 120-1 to 120-N. there is.

In addition, the display unit of the terminal devices 120-1 to 120-N may display information about a series of operation states and operation results that occur while the functions of the terminal devices 120-1 to 120-N are performed. Also, the display unit of the terminal devices 120-1 to 120-N may display menus of the terminal devices 120-1 to 120-N, user data input by the user, and the like. Here, the display unit of the terminal devices 120-1 to 120-N includes a liquid crystal display (LCD), an ultra-thin liquid crystal display (TFT-LCD, Thin Film Transistor LCD), and a light emitting diode (LED, Light Emitting Diode). ), organic light emitting diodes (OLED, Organic LED), active organic light emitting diodes (AMOLED, Active Matrix OLED), retina display, flexible display, and three-dimensional display. can In this case, when the display units of the terminal devices 120-1 to 120-N are configured in the form of a touch screen, the display units of the terminal devices 120-1 to 120-N are those of the terminal devices 120-1 to 120-N. Some or all of the functions of the input unit may be performed. In particular, the display unit of the terminal devices 120-1 to 120-N according to the present invention may display information related to execution of content provided based on cloud computing on a screen.

In addition, the storage unit of the terminal devices 120-1 to 120-N is a device for storing data, and includes a main memory device and an auxiliary memory device, and is used for the functional operation of the terminal devices 120-1 to 120-N. You can store the applications you need. The storage unit of the terminal devices 120-1 to 120-N may largely include a program area and a data area. Here, when each function is activated in response to a user's request, the terminal devices 120-1 to 120-N execute corresponding application programs under the control of the controller to provide each function. In particular, the storage unit of the terminal devices 120-1 to 120-N according to the present invention includes an operating system for booting the terminal devices 120-1 to 120-N, a program for uploading or downloading content based on cloud computing, and the like. can be saved Also, the storage unit of the terminal devices 120-1 to 120-N may store a content DB for storing a plurality of contents and information of the terminal devices 120-1 to 120-N. In this case, the content DB includes execution data for executing the content and attribute information on the content, and content usage information according to the content execution may be stored. In addition, the information of the terminal devices 120-1 to 120-N may include terminal specification information.

In addition, the communication unit of the terminal devices 120-1 to 120-N may perform a function for transmitting and receiving data through the cloud streaming server 110 and the network 130 . Here, the communication unit of the terminal devices 120-1 to 120-N may include an RF transmitting means for up-converting and amplifying the frequency of the transmitted signal, and an RF receiving means for low-noise amplifying the received signal and down-converting the frequency. there is. The communication unit of the terminal devices 120-1 to 120-N may include at least one of a wireless communication module and a wired communication module. In addition, the wireless communication module is a configuration for transmitting and receiving data according to a wireless communication method, and when the terminal devices 120-1 to 120-N use wireless communication, a wireless network communication module, a wireless LAN communication module, and a wireless fan communication Data can be transmitted and received to the cloud streaming server 110 by using any one of the modules. In addition, the wired communication module is for transmitting and receiving data by wire. The wired communication module may connect to the network 130 through a wire and transmit/receive data to/from the cloud streaming server 110 . That is, the terminal devices 120-1 to 120-N may connect to the network 130 using a wireless communication module or a wired communication module, and may transmit/receive data to and from the cloud streaming server 110 through the network 130 . . In particular, the network 130 according to the present invention communicates with the cloud streaming server 110 or other terminal devices 120-1 to 120-N to transmit and receive data required to upload or download content based on cloud computing. .

In addition, the control unit of the terminal devices 120-1 to 120-N may be a process device for driving an operating system (OS, Operation System) and each configuration. For example, the control unit is a cloud streaming server 110 When accessing the cloud streaming server 110 through a separate service application, it is possible to control the overall process of executing the service application according to the user's request, and simultaneously with the execution of the cloud It is possible to control so that a service use request is transmitted to the streaming server 110, and at this time, it is possible to control so that information of the terminal devices 120-1 to 120-N required for user authentication is transmitted together.

Also, the controller of the terminal devices 120-1 to 120-N may execute specific content stored in the storage unit of the terminal devices 120-1 to 120-N according to a user's request. In this case, the controller may store the content use history according to the content execution as content use information.

In addition, the control unit of the terminal devices 120-1 to 120-N collects execution data for executing the content, content information including attribute information about the content, and content use information, which is information according to the content use history, together in the cloud. It can be uploaded by sending it to the streaming server 110 . Thereafter, the control unit may delete the uploaded content transmitted to the cloud streaming server 110 from the storage unit of the terminal devices 120-1 to 120-N according to the user's request, and access the cloud streaming server 110 Thus, the content may be executed and used through the cloud streaming server 110 .

In addition, the control unit of the terminal devices (120-1 ~ 120-N) to access the cloud streaming server 110 to download the content from the other terminal devices (120-1 ~ 120-N) and then control to be stored in the storage unit. Also, when executing content through the cloud streaming server 110 , only data necessary for execution may be received and then the content may be controlled to be executed.

The network 130 is a concept that provides a path for transferring data between the cloud streaming server 110 and the terminal devices 120-1 to 120-N, and encompasses both existing networks and networks that can be developed in the future. am. For example, the network 130 may include 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 between the mobile body and the outside of the mobile device, and communication between the earth station and the earth station using satellites. It may be a satellite communication network that provides Meanwhile, the transmission method 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, the network used between the cloud streaming server 110 and the terminal devices 120-1 to 120-N in FIG. 1 may be different from the network used between the terminal devices 120-1 to 120-N. and may be the same.

By providing a cloud streaming service through such a cloud streaming service system, the cloud streaming server 110 can reduce the load during service according to the changed image quality, and also the image in the terminal devices 120-1 to 120-N. When rendering, the load is reduced, and the service can be provided more quickly. In addition, the service may be provided without being greatly affected by the performance of the terminal devices 120-1 to 120-N.

2 is a block diagram showing an example of the cloud streaming server shown in FIG.

Referring to FIG. 2 , the cloud streaming server 110 shown in FIG. 1 includes a communication unit 210 , a capture unit 220 , an encoding unit 230 , an encoding control unit 240 , a sending unit 250 and a storage unit ( 260).

The communication unit 210 serves to transmit and receive information related to a plurality of terminals through a communication network such as the network shown in FIG. 1 . In particular, the communication unit 210 according to an embodiment of the present invention may receive a request for a cloud streaming service from a terminal, and provide an execution screen of an application corresponding to the cloud streaming service requested by the terminal to the terminal.

At this time, it is possible to receive the application execution screen from the cloud streaming server for the cloud streaming service requested by the terminal.

The capture unit 220 captures the changed image by comparing frames corresponding to the application execution screen received according to the user's request.

The video codec-based cloud streaming technique can perform encoding by capturing all frames corresponding to the screen on which the application operates. However, if the frame-to-frame change is not large on the screen where the application is running, still image encoding is performed by capturing only the changed area of the frame compared to the previous frame, as in the image-based cloud streaming technique, and displayed on the user's terminal device. The display can be displayed in such a way that the parts except the change area are shown the same and only the change area is changed.

In this case, the changed image may be captured by comparing the current frame with the previous frame among the frames. For example, if the current frame is changed compared to the previous frame when the current frame and the previous frame are compared, the changed area of the screen area of the current frame may be captured as a changed image. Also, the captured changed image may have various sizes or properties according to an input signal input from the user's terminal.

Also, it is possible to detect sections in which the changes between frames are small among the frames, and capture the changed images in the sections in which the changes between frames are small. For example, it may be inefficient to provide an image-based cloud streaming service because the number of images to be captured is large in a section where there is a lot of change between frames. Accordingly, in such a section with many changes, a service is performed through a video codec-based cloud streaming technique, and a changed image can be captured in order to perform an image-based cloud streaming service only in a section with little change between frames.

The encoding unit 230 simultaneously encodes the changed image in two encoding methods corresponding to high and low quality, respectively, as a still image.

When encoding an image for an image-based cloud streaming service in the cloud streaming server 110, the amount of load generated in the cloud streaming server 110 during encoding, the quality of the image, or the performance of a terminal that receives and renders the encoded image, etc. An encoding method may be determined in consideration of

In this case, the PNG format can be used to apply the transparency effect of the image, and the encoding method corresponding to the PNG format can be variously used, including PNG32bit, palette PNG, and lossyPNG.

In the PNG32bit encoding method, the image quality is good when encoding still images, but the data size of the image is large, which may cause a large load on the cloud streaming server 110 during encoding. Also, since the data is large, when the bandwidth of the transmission network is low, the transmission speed may be lowered.

Palette PNG encoding method is an encoding method also called Indexed PNG encoding method or PNG8bit encoding method. Since it creates an index of a few colors and uses each pixel by replacing the color included in the index, the data size of the image is reduced when encoding still images. can Therefore, although transmission speed can be guaranteed, since colors are expressed in 8-bit, image quality may deteriorate when the number of colors is large, such as an image with gradation effect.

The lossy PNG encoding method performs still image encoding by setting the image quality degradation level when encoding still images. The Lossy PNG encoding method can be considered an intermediate level between the PNG32-bit encoding method and the Palette PNG encoding method in terms of quality and data size.

In this case, it is possible to simultaneously encode still images using the lossyPNG encoding method corresponding to high quality and the palette PNG encoding method corresponding to low quality. For example, in order to basically improve the speed of a cloud streaming service, an image that has been changed to a palette PNG encoding method may be encoded as a still image. However, when the changed image is a high-quality image, the image quality of the still image-encoded image using the palette PNG encoding method may be severely degraded.

Therefore, still image encoding can be performed simultaneously with the palette PNG and lossyPNG encoding method that can guarantee an appropriate level of image quality.

In this case, the encoding method corresponding to the high quality may correspond to any one of the lossyPNG encoding method and the PNG32bit encoding method. For example, depending on the performance of the cloud streaming server 110, the performance of the terminal, or the number of users currently connected to the cloud streaming server 110, the service delay is reduced even if the high-definition image is encoded with the PNG32bit encoding method and streamed. may not occur. Therefore, when encoding a still image of a high-quality image, it is possible to perform still image encoding by appropriately using a lossyPNG or PNG32bit encoding method according to various environmental information.

The encoding control unit 240 checks the number of colors of the image changed while encoding the still image, and determines whether encoding of the still image corresponding to the high quality is stopped based on the number of colors. For example, as a method for determining whether the changed image is a high-quality image or a low-quality image, the number of colors of the changed image may be checked. The number of colors is the number of colors that pixels constituting an image have. A high-quality image may be composed of pixels corresponding to a large number of colors, and a low-quality image may be composed of pixels corresponding to a lower number of colors than high-quality images. can

Therefore, if the changed image checked according to the number of colors is a low-quality image, performing still image encoding corresponding to a high-quality image may be unnecessarily wasting resources of the cloud streaming server 110 . Therefore, it is possible to determine whether the changed image is a high-quality image or a low-quality image according to the number of colors of the changed image, and whether to stop encoding a still image corresponding to the high-quality image.

In this case, when the number of colors is less than or equal to the preset reference number of colors, encoding of still images corresponding to high quality may be stopped using a high quality encoding stop message. That is, since the changed image is a low-quality image with a small number of colors, there may be no deterioration in the image quality of the changed image or the degree of deterioration may not be large even if the still image encoding corresponding to the low-quality image is encoded and streamed.

Accordingly, in order to stop unnecessarily performing high-definition still image encoding, by generating a high-definition encoding stop message and transmitting it to the encoding unit 230 , encoding of the still image corresponding to the high-definition may be stopped.

In addition, when the number of colors exceeds a preset reference number of colors, encoding of still images corresponding to low quality may be stopped. However, since the load of the cloud streaming server 110 does not occur significantly when performing still image encoding corresponding to low quality, the following process may be performed without stopping.

The sending unit 250 performs an image-based cloud streaming service by transmitting a still image-encoded image of either high or low quality to the terminal in order to display an application execution screen on the user's terminal.

The user's terminal may provide a cloud streaming service by rendering the application execution screen transmitted from the cloud streaming server 110 and displaying the rendered application execution screen so that the user can see it.

Therefore, in order to provide an image-based cloud streaming service according to an embodiment of the present invention, the cloud streaming server 110 may transmit a still image-encoded image of high or low quality to the terminal.

In this case, when encoding of the still image corresponding to the high quality is performed without interruption, the changed image encoded with the high quality still image may be transmitted to the terminal. For example, if encoding of a still image corresponding to high quality is not stopped, it may mean that the number of colors in the changed image exceeds a preset reference number of colors. That is, since the changed image can be interpreted as a high-quality image, it is possible to transmit the changed image encoded with a high-quality still image to the terminal.

Also, even if the still image encoding corresponding to the high quality has not been stopped, the changed image encoded with the still image with the low quality may exist together with the changed image encoded with the still image with the high quality. At this time, the low-quality still image-encoded changed image may be deleted or stored in the cache memory of the cloud streaming server 110 according to the frequency at which the changed image is requested by the user.

At this time, when encoding of the still image corresponding to the high quality is stopped, the changed image encoded with the still image in the low quality may be transmitted to the terminal. For example, if encoding of a still image corresponding to high quality is stopped, it may mean that the number of colors in the changed image is less than or equal to a preset reference number of colors. That is, since the changed image can be interpreted as a low-quality image, it is possible to transmit a changed image encoded with a low-quality still image to the terminal.

The storage unit 260 stores various information generated in the process of the cloud streaming service according to the embodiment of the present invention as described above.

According to an embodiment, the storage unit 260 may be configured independently of the cloud streaming server 110 to support a function for a cloud streaming service. In this case, the storage unit 260 may operate as a separate mass storage and may include a control function for performing an operation.

In addition, the cloud streaming server 110 configured as described above compares the frames of the application execution screen received according to the user's request and performs a video codec-based cloud streaming service in a part with a lot of change, and in a part with a small change Image-based cloud streaming service can be performed through image capture.

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

On the other hand, the cloud streaming server 110 is equipped with a memory can store information in the device. In one implementation, the memory is a computer-readable medium. In one implementation, the memory may be a volatile memory unit, and in another implementation, the memory may be a non-volatile 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.

3 is a diagram illustrating an image-based cloud streaming service process according to the present invention.

Referring to FIG. 3 , in the image-based cloud streaming service, input from the user is first performed in the terminal area 315 , and the user input may be transmitted to the application server area 305 .

In the application server area 305, an application may be executed according to a user input. Thereafter, the application server area 305 may transmit the execution screen of the application executed to provide the user with the application execution result to the cloud streaming server area 300 .

In the cloud streaming server area 300, it is possible to capture a changed image on the received application execution screen, and perform still image encoding on the changed image using a low-quality palette PNG encoding method and a high-quality lossyPNG encoding method.

At this time, the cloud streaming server area 300 checks the number of colors of the image changed at the same time as performing the still image encoding of the two methods, and determines whether to stop encoding the still image corresponding to the high-quality lossyPNG encoding method based on the number of colors can That is, as a result of checking the number of colors in the changed image, if the changed image is a high-quality image having a number of colors exceeding the preset reference color number, encoding of still images corresponding to the lossyPNG encoding method can be continued without stopping. However, if the changed image is a low-quality image with a number of colors less than or equal to the preset reference number of colors, the still image encoding corresponding to the lossyPNG encoding method can be stopped because the service can be performed only by encoding the still image corresponding to the palette PNG encoding method. can

By including a process of stopping still image encoding corresponding to the lossyPNG encoding method according to the changed image quality in this way, it is possible to reduce the load in the cloud streaming server area 300 that may be unnecessary.

Thereafter, the cloud streaming server area 300 may provide an image-based cloud streaming service by streaming the still image-encoded changed image to the terminal. At this time, the still image-encoded changed image to be streamed may be determined by checking whether the still image encoding of the lossyPNG encoding method is stopped at the encoder end.

For example, if the encoding of the lossyPNG encoding method is stopped at the encoder end, the changed image may be recognized as a low-quality image and the still image encoded by the palette PNG encoding method may be streamed. In addition, if the encoding of the still image of the lossyPNG encoding method is not stopped at the encoder stage, the changed image can be recognized as a high-quality image and the changed image encoded with the lossyPNG encoding method can be streamed. If, at the encoder stage, still image encoding of the lossyPNG encoding method is not stopped, but there is no changed image encoded with the lossyPNG encoding method, it is determined that an error has occurred in the cloud streaming server and encoding of the corresponding changed image is performed again You may.

Thereafter, in the terminal area 315 , the still image-encoded changed image transmitted from the cloud streaming server area 300 may be rendered and displayed to the user.

At this time, since only the image of the statically changed part of the application execution screen is rendered and displayed, even if the performance of the user terminal is poor, the service can be smoothly provided without delay due to rendering.

4 is a diagram illustrating a process of detecting an image to be captured by comparing frames according to the present invention.

Referring to FIG. 4 , in the process of detecting an image to be captured by comparing frames according to the present invention, frames of a portion of an application execution screen in response to a user request with little change in screen may be acquired first.

In this case, it may be more efficient to provide an application execution screen to the user through a video codec-based cloud streaming service for a portion with a large number of screen changes.

Thereafter, the current frame 420 and the previous frame 410 may be compared among the frames of the small change portion. For example, if the current frame 420 and the previous frame 410 shown in FIG. 4 are compared, there is no change in the A region of the two frames, but the B region of the previous frame 410 is B` in the current frame 420 . You can see that it has been converted to .

Therefore, in the cloud streaming server, such a change can be confirmed, and the changed area B` can be captured as the changed area 430 . That is, it is possible to capture an image corresponding to the changed area 430 in the capture end of the cloud streaming server.

In addition, when comparing the current frame 420 with the previous frame 410 , when multiple regions are identified, such as the changed region 430 , one region including all the changed regions is included in the changed region 430 . ) can be recognized and captured. In addition, it is also possible to perform an image-based cloud streaming service by recognizing all the changed regions as the changed regions 430 , and capturing the plurality of changed regions 430 .

5 is a diagram illustrating a method of including color information in a pixel according to a PNG32-bit method.

Referring to FIG. 5 , in the method of including color information in a pixel according to the PNG32-bit method, each color corresponding to R (Red), G (Green), and B (Blue) is included in the pixel 510 as 1 byte data. can do. Accordingly, one pixel 510 may have a data size of 3 bytes, and the entire image may have a data size equal to the number of pixels included in the image multiplied by a value of 3 bytes.

In this case, in the case of the PNG32-bit method, each pixel may have a data size of 32 bits, that is, a data size of 4 bytes. In this case, 3 bytes among 4 bytes may be data of RGB color as described above, and the remaining 1 byte may be data for representing transparent information for a transparent effect.

6 is a diagram illustrating a method of including color information in a pixel according to the palette PNG method.

Referring to FIG. 6 , in a method of including color information in a pixel according to the palette PNG method, information corresponding to a color index may be included in each pixel 610 as 1 byte data. Accordingly, one pixel 610 may have a data size of 1 Byte, and the entire image may have a data size equal to the number of pixels included in the image multiplied by a value of 1 Byte.

The reason why the palette PNG method is called the PNG8-bit method or the Indexed PNG method may be because the data size of one pixel 610 is 1 byte corresponding to 8 bits, and a color value is expressed through a color index.

Therefore, when performing a cloud streaming service, when the cloud streaming server encodes the image in the palette PNG method, the size of the data can be reduced to a quarter of that of encoding in the PNG32bit method shown in FIG. 5 . However, since the number of colors that the pixel 610 of the palette PNG method can represent is limited to 1 byte, the image quality may deteriorate.

7 is a diagram illustrating an example of a color index generated in the palette PNG method.

Referring to FIG. 7 , the color index 710 generated in the palette PNG method includes 8 bits, that is, 256 color information, which is a value corresponding to the power of 2 to the 8th power, because a pixel of the palette PNG method has a data size of 1 Byte. there is.

Referring to FIG. 7 as an example, the color corresponding to palette number 0 may be a color having values of Red '0', Green '0', and Blue'0' in the RGB color code. In addition, the color corresponding to palette number 1 and the color corresponding to palette number 2 are colors having the values of Red '127', Green '127', and Blue'127' in the RGB color code, Red '255', Green may be a color having a value of '255' and Blue'255'.

As described above, the color index 710 composed of a total of 256 colors using the RGB color code value may be configured based on the colors constituting the changed image captured by comparing the frames of the application execution screen. For example, if the color constituting the changed image is a blue series, many colors of the blue series may be included in the color index 710 as well.

By configuring the color index 710 in consideration of the colors constituting the changed image as described above, deterioration in image quality of the changed image can be minimized.

8 is an operation flowchart illustrating an image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention.

8, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention captures a changed image by comparing frames corresponding to the application execution screen received in response to a user request (S810).

The video codec-based cloud streaming technique can perform encoding by capturing all frames corresponding to the screen on which the application operates. However, if the frame-to-frame change is not large on the screen where the application is running, still image encoding is performed by capturing only the changed area of the frame compared to the previous frame, as in the image-based cloud streaming technique, and displayed on the user's terminal device. The display can be displayed in such a way that the parts except the change area are shown the same and only the change area is changed.

In this case, the changed image may be captured by comparing the current frame with the previous frame among the frames. For example, if the current frame is changed compared to the previous frame when the current frame and the previous frame are compared, the changed area of the screen area of the current frame may be captured as a changed image. Also, the captured changed image may have various sizes or properties according to an input signal input from the user's terminal.

Also, it is possible to detect sections in which the changes between frames are small among the frames, and capture the changed images in the sections in which the changes between frames are small. For example, it may be inefficient to provide an image-based cloud streaming service because the number of images to be captured is large in a section where there is a lot of change between frames. Accordingly, in such a section with many changes, a service is performed through a video codec-based cloud streaming technique, and a changed image can be captured in order to perform an image-based cloud streaming service only in a section with little change between frames.

In addition, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention simultaneously encodes the changed image in two encoding methods corresponding to high and low quality, respectively (S820).

When encoding an image for an image-based cloud streaming service in a cloud streaming server, the encoding method is selected in consideration of the load generated by the cloud streaming server during encoding, the quality of the image, or the performance of the terminal that receives and renders the encoded image. can decide

In this case, the PNG format can be used to apply the transparency effect of the image, and the encoding method corresponding to the PNG format can be variously used, including PNG32bit, palette PNG, and lossyPNG.

The PNG32bit encoding method has good image quality when encoding a still image, but the data size of the image is large, which can cause a large load on the cloud streaming server during encoding. Also, since the data is large, when the bandwidth of the transmission network is low, the transmission speed may be lowered.

Palette PNG encoding method is an encoding method also called Indexed PNG encoding method or PNG8bit encoding method. Since it creates an index of a few colors and uses each pixel by replacing the color included in the index, the data size of the image is reduced when encoding still images. can Therefore, although transmission speed can be guaranteed, since colors are expressed in 8-bit, image quality may deteriorate when the number of colors is large, such as an image with gradation effect.

The lossy PNG encoding method performs still image encoding by setting the image quality degradation level when encoding still images. The Lossy PNG encoding method can be considered an intermediate level between the PNG32-bit encoding method and the Palette PNG encoding method in terms of quality and data size.

In this case, it is possible to simultaneously encode still images using the lossyPNG encoding method corresponding to high quality and the palette PNG encoding method corresponding to low quality. For example, in order to basically improve the speed of a cloud streaming service, an image that has been changed to a palette PNG encoding method may be encoded as a still image. However, when the changed image is a high-quality image, the image quality of the still image-encoded image using the palette PNG encoding method may be severely degraded.

Therefore, still image encoding can be performed simultaneously with the palette PNG and lossyPNG encoding method that can guarantee an appropriate level of image quality.

In this case, the encoding method corresponding to the high quality may correspond to any one of the lossyPNG encoding method and the PNG32bit encoding method. For example, depending on the performance of the cloud streaming server, the performance of the terminal, or the number of users currently connected to the cloud streaming server, the service delay may not occur even if the high-definition image is encoded with the PNG32bit encoding method and then streamed. Therefore, when encoding a still image of a high-quality image, it is possible to perform still image encoding by appropriately using a lossyPNG or PNG32bit encoding method according to various environmental information.

In addition, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention checks the number of colors of an image changed at the same time as performing still image encoding, and stops encoding of still images corresponding to high quality based on the number of colors It is determined whether or not (S830). For example, as a method for determining whether the changed image is a high-quality image or a low-quality image, the number of colors of the changed image may be checked. The number of colors is the number of colors that pixels constituting an image have. A high-quality image may be composed of pixels corresponding to a large number of colors, and a low-quality image may be composed of pixels corresponding to a lower number of colors than high-quality images. can

Therefore, if the changed image checked according to the number of colors is a low-quality image, performing still image encoding corresponding to a high-quality image may be unnecessarily wasting resources of the cloud streaming server. Therefore, it is possible to determine whether the changed image is a high-quality image or a low-quality image according to the number of colors of the changed image, and whether to stop encoding a still image corresponding to the high-quality image.

In this case, when the number of colors is less than or equal to the preset reference number of colors, encoding of still images corresponding to high quality may be stopped using a high quality encoding stop message. That is, since the changed image is a low-quality image with a small number of colors, there may be no deterioration in the image quality of the changed image or the degree of deterioration may not be large even if the still image encoding corresponding to the low-quality image is encoded and streamed.

Accordingly, in order to stop the unnecessarily performed high-quality still image encoding, the high-definition encoding stop message may be generated and transmitted to the encoder to stop encoding the still image corresponding to the high-definition.

In addition, when the number of colors exceeds a preset reference number of colors, encoding of still images corresponding to low quality may be stopped. However, when performing still image encoding corresponding to low quality, the load on the cloud streaming server does not occur significantly, so the next process may be performed without interruption.

In addition, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention transmits a still image-encoded image of either high or low quality to the terminal in order to display an application execution screen on the user's terminal, and is image-based of the cloud streaming service (S840).

The user's terminal may provide a cloud streaming service by rendering the application execution screen transmitted from the cloud streaming server and displaying the rendered application execution screen so that the user can see it.

Therefore, in order to provide an image-based cloud streaming service according to an embodiment of the present invention, the cloud streaming server may transmit a still image-encoded image of high or low quality to the terminal.

In this case, when encoding of the still image corresponding to the high quality is performed without interruption, the changed image encoded with the high quality still image may be transmitted to the terminal. For example, if encoding of a still image corresponding to high quality is not stopped, it may mean that the number of colors in the changed image exceeds a preset reference number of colors. That is, since the changed image can be interpreted as a high-quality image, it is possible to transmit the changed image encoded with a high-quality still image to the terminal.

Also, even if the still image encoding corresponding to the high quality has not been stopped, the changed image encoded with the still image with the low quality may exist together with the changed image encoded with the still image with the high quality. At this time, the changed image encoded with the still image in low quality may be deleted or stored in the cache memory of the cloud streaming server according to the frequency at which the changed image is requested by the user.

At this time, when encoding of the still image corresponding to the high quality is stopped, the changed image encoded with the still image in the low quality may be transmitted to the terminal. For example, if encoding of a still image corresponding to high quality is stopped, it may mean that the number of colors in the changed image is less than or equal to a preset reference number of colors. That is, since the changed image can be interpreted as a low-quality image, it is possible to transmit a changed image encoded with a low-quality still image to the terminal.

Although not shown in FIG. 8, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention serves to transmit and receive information related to a plurality of terminals through a communication network such as the network shown in FIG. . In particular, it is possible to receive a request for a cloud streaming service from the terminal, and provide an execution screen of an application corresponding to the cloud streaming service requested by the terminal to the terminal.

At this time, it is possible to receive the application execution screen from the cloud streaming server for the cloud streaming service requested by the terminal.

Although not shown in FIG. 8, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention stores various information generated in the process of the cloud streaming service according to the embodiment of the present invention as described above.

According to an embodiment, a database or storage storage for storing various information may be configured independently of a cloud streaming server to support a function for a cloud streaming service. In this case, the database or storage storage may operate as a separate mass storage and may include a control function for performing the operation.

9 is a detailed operation flowchart illustrating an image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention.

9, in the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention, first, the cloud streaming server receives an application execution screen according to a user request from the application server (S910).

At this time, the cloud streaming server may receive the application execution screen from the application server through a communication network such as the network shown in FIG. 1 .

In addition, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention captures the changed image by comparing the frames of the application execution screen (S920).

In this case, the changed image may be captured by comparing the current frame and the previous frame among the frames.

Also, it is possible to detect sections in which the changes between frames are small among the frames, and capture the changed images in the sections in which the changes between frames are small. In this case, it may be inefficient to provide an image-based cloud streaming service because the number of images to be captured in a section with a lot of change is large. Accordingly, in such a section with many changes, a service is performed through a video codec-based cloud streaming technique, and a changed image can be captured in order to perform an image-based cloud streaming service only in a section with little change between frames.

In addition, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention encodes a changed image in two encoding methods corresponding to high and low quality, respectively, and checks the number of colors of the changed image at the same time ( S930).

In this case, the PNG format can be used to apply the transparency effect of the image when encoding the still image, and the encoding method corresponding to the PNG format can be used in various ways, including PNG32bit, palette PNG, and lossyPNG.

In this case, it is possible to simultaneously encode still images using the lossyPNG encoding method corresponding to high quality and the palette PNG encoding method corresponding to low quality.

Also, the encoding method corresponding to the high quality may correspond to any one of the lossyPNG encoding method and the PNG32bit encoding method. For example, depending on the performance of the cloud streaming server, the performance of the terminal, or the number of users currently connected to the cloud streaming server, the service delay may not occur even if the high-definition image is encoded with the PNG32bit encoding method and then streamed. Therefore, when encoding a still image of a high-quality image, it is possible to perform still image encoding by appropriately using a lossyPNG or PNG32bit encoding method according to various environmental information.

In addition, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention determines whether the number of colors of the changed image is less than or equal to a preset reference number of colors (S935).

If it is determined in step S935 that is less than or equal to the preset reference number of colors, encoding of still images corresponding to high quality is stopped (S940).

In this case, the number of colors is the number of colors that pixels constituting the image have. A high-quality image may consist of pixels corresponding to a large number of colors, and a low-quality image may include pixels corresponding to a lower number of colors than high-quality images. can be composed of

Therefore, if the changed image checked according to the number of colors is a low-quality image, performing still image encoding corresponding to a high-quality image may be unnecessarily wasting resources of the cloud streaming server. Therefore, according to the number of colors of the changed image, it is checked whether the changed image is a high-quality image or a low-quality image, and if the changed image is a low-quality image, it is possible to stop encoding a still image corresponding to the high quality.

In this case, the still image encoding corresponding to the high quality may be stopped by using the high quality encoding stop message.

If it is determined in step S935 that it is not less than or equal to the preset reference color number, it is determined whether encoding of still images corresponding to high quality has been stopped (S945).

If it is determined in step S945 that encoding of the still image corresponding to the high quality is stopped, the changed image encoded with the still image in the low quality is transmitted to the terminal (S950).

At this time, if encoding of the still image corresponding to the high quality is stopped, it may mean that the number of colors in the changed image is less than or equal to the preset reference color number.

If it is determined in step S945 that encoding of the still image corresponding to the high quality has not been stopped, the changed still image encoded in the high quality is transmitted to the terminal (S960).

At this time, if encoding of the still image corresponding to the high quality is not stopped, it may mean that the number of colors in the changed image exceeds the preset reference number of colors. That is, since the changed image can be interpreted as a high-quality image, it is possible to transmit the changed image encoded with a high-quality still image to the terminal.

In addition, the image cloud streaming method using simultaneous encoding according to an embodiment of the present invention compares frames of an application execution screen received in response to a user request and performs a video codec-based cloud streaming service in a part with many changes, In the small part, image-based cloud streaming service can be performed through image capture.

10 is a diagram illustrating an image cloud streaming process using simultaneous encoding according to an embodiment of the present invention.

Referring to FIG. 10 , in the image cloud streaming process using simultaneous encoding according to an embodiment of the present invention, a user input input by a user through a terminal 120-1 is first received from an application server (S1002)

Thereafter, the application server executes the application according to the user input (S1004).

Thereafter, the application server transmits the application execution screen to the cloud streaming server 110 (S1006).

At this time, the cloud streaming server 110 may receive the application execution screen through the communication unit. The communication unit may transmit/receive information related to a plurality of terminals through a network, and may transmit/receive application information according to a user input to/from an application server.

In addition, the cloud streaming server 110 may transmit the application execution screen received through the communication unit to the capture unit of the cloud streaming server 110 .

Thereafter, the capture unit of the cloud streaming server 110 captures the changed image by comparing the frames of the received application execution screen (S1008). In this case, a video codec-based cloud streaming service may be performed for a section in which many changed parts are compared by comparing frames.

After that, the cloud streaming server 110 encodes the changed image in the encoding unit as a still image (S1010), and at the same time checks the number of colors of the changed image in the encoding control unit (S1012).

In this case, the encoding unit may encode the still image at the same time by using encoding methods corresponding to the low image quality and the high image quality, respectively.

After that, while the encoding unit of the cloud streaming server 110 performs still image encoding in two ways, the encoding control unit determines whether to stop encoding the still image corresponding to the high quality based on the changed number of colors of the image (S1014) ).

For example, if the number of colors of the changed image is checked to be less than or equal to a preset standard, it is determined that the changed image is an image of low quality, and a high quality encoding stop message is transmitted (S1016) to stop encoding a still image corresponding to high quality.

In addition, when it is checked that the number of colors of the changed image exceeds a preset criterion, it is determined that the changed image is a high-quality image, and encoding of a still image corresponding to the high-quality image can be continued without stopping.

After that, depending on whether the encoding control unit stops or not, the encoding of the still image is completed in two ways or the encoding of the still image is completed by the encoding method corresponding to the low image quality (S1018).

After that, the sending unit of the cloud streaming server 110 checks whether encoding of the still image corresponding to the high quality has been stopped (S1020).

At this time, the reason why the sending unit checks whether encoding of the still image corresponding to the high quality is stopped is that the sending unit has to determine the quality of the still image-encoded changed image to be transmitted to the terminal 120 - 1 .

Thereafter, the sending unit of the cloud streaming server 110 transmits the still image-encoded changed image to the terminal 120-1 (S1022).

At this time, if it is confirmed by the sending unit that encoding of the still image corresponding to the high quality has been stopped, the changed image may be recognized as a low quality image and the changed image encoded with the still image in low quality may be transmitted. In addition, if it is confirmed by the sending unit that encoding of the still image corresponding to the high quality is not stopped, the changed image may be recognized as a high quality image and the changed image encoded with the still image in high quality may be transmitted.

Thereafter, the terminal 120-1 renders the still image-encoded changed image received from the cloud streaming server 110 (S1024).

In this case, since only the changed image is rendered on the application execution screen, the difference in rendering speed due to the performance difference of the terminal 120 - 1 can be reduced. That is, rendering can be performed smoothly even in older terminals with poor performance.

Thereafter, the terminal 120-1 may display an application execution screen to the user (S1026) to provide an image-based cloud streaming service.

The image cloud streaming service method using simultaneous encoding according to the present invention may be implemented in the form of a program command that can be executed through 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. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - Includes magneto-optical media, and any form of hardware device specially 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 codes that can be executed by a computer using an interpreter or the like as well as machine language codes such as those generated 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, in the cloud streaming service system, the image cloud streaming service method using simultaneous encoding, and the apparatus for the same according to the present invention, the configuration and method of the embodiments described above are not limitedly applicable, but the above embodiment Examples may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

According to the present invention, the changed image is captured by comparing frames corresponding to the application execution screen received according to the user's request, the changed image is simultaneously encoded with two encoding methods corresponding to high and low quality, respectively, and still image encoding At the same time, the number of colors in the changed image is checked, and based on the number of colors, it is determined whether encoding of still images corresponding to high quality is stopped. An image-based cloud streaming service can be performed by transmitting the image-encoded and changed image to the terminal. Furthermore, a cloud streaming service that guarantees both image quality and service speed provided by performing a batch encoding of images with image quality below a certain level during service, and encoding high-definition images in a high-definition encoding method to provide the service can provide

110: cloud streaming server 120-1 to 120-N: terminal device
130: network 210: communication unit
220: capture unit 230: encoding unit
240: encoding control unit 250: sending unit
260: storage unit 300: cloud streaming server area
305: application server area 315: terminal area
410: previous frame 420: current frame
430: changed area 510, 610: pixel
710: color index

Claims (5)

a capture unit for capturing a changed image by comparing frames corresponding to the application execution screen;
an encoding unit that encodes the changed image as a still image using an encoding method selected in consideration of the number of colors of the changed image; and
A sending unit that transmits the still image-encoded changed image to a user's terminal
including,
the encoding unit
When the number of colors exceeds a preset number of reference colors, encoding the changed image as a still image in a first encoding method supporting a bitmap image exceeding the preset reference number of colors in response to high quality;
Cloud streaming server, characterized in that when the number of colors is less than or equal to the preset number of reference colors, encoding the changed image as a still image in a second encoding method supporting a bitmap image less than or equal to the preset number of reference colors in response to low image quality . delete ◈Claim 3 has been abandoned at the time of payment of the registration fee.◈ The method according to claim 1,
The encoding method corresponding to the high quality corresponds to any one of the lossyPNG encoding method and the PNG32bit encoding method, and the encoding method corresponding to the low quality corresponds to the palette PNG encoding method. ◈Claim 4 was abandoned when paying the registration fee.◈ 4. The method according to claim 3,
the encoding unit
Cloud streaming server, characterized in that when encoding is performed in the palette PNG encoding method, encoding is performed based on a color index composed of colors corresponding to the changed image. ◈Claim 5 was abandoned when paying the registration fee.◈ 5. The method according to claim 4,
The color index is
Cloud streaming server, characterized in that it consists of 256 colors constituting the changed image based on the value of the RGB color code.

Images