KR20160093929A - System for cloud streaming service, method of image cloud streaming service using simultaneous encoding and apparatus for the same - Google Patents

Abstract

Disclosed are a cloud streaming service system, an image cloud streaming service method using simultaneous encoding, and a device therefor. The present invention performs an image based cloud streaming service by capturing an image which is changed by comparing frames of an application execution screen according to a user request; performing still image encoding for a high quality still image and a low quality still image at the same time; checking the number of colors of the changed image while performing the still image encoding, and determining the stop of the still image encoding corresponding to the high quality still image; and transmitting the high quality or low quality still image encoding changed image to a terminal. Provided is the image based cloud streaming service with improved image quality and speed.

Description

TECHNICAL FIELD [0001] The present invention relates to a cloud streaming service system, a cloud streaming service system, an image cloud streaming service method using simultaneous encoding, and a device for such an image cloud streaming service method.

The present invention relates to a technology for providing an image cloud streaming service by simultaneously performing encoding with low image quality and high image quality. More particularly, the present invention relates to a technique of simultaneously encoding an image to be transmitted to a user terminal with a low image quality and a high image quality, The present invention relates to a cloud streaming service system capable of rapidly providing services with improved image quality by determining whether or not encoding is to be stopped, a method of image cloud streaming service using simultaneous encoding, and an apparatus therefor.

The rapid development of the Internet has resulted in a rapid increase in the communication speed of an individual. The improvement in the communication speed can be achieved by downloading or uploading a large amount of data by accessing a computer located at a remote place, or by using a remote computer control program, As well as providing an environment in which a remote computer can be used.

In addition, as a variety of applications have been developed for mobile communication terminals such as smart phones, many virtualization technologies have been proposed for driving applications requiring high performance in relatively low performance user terminals.

Among them, the application is driven on the server, the driving screen is compressed through video encoding and transmitted to the client, and the client reproduces the transmitted video to generate a screen virtualization Cloud streaming service is becoming popular.

This cloud streaming service basically adopts the cloud streaming method based on the video codec. However, even when a static screen such as a menu display is served, the entire screen is unnecessarily captured and operated using a video codec, which is inefficient in the entire system.

Accordingly, an image-based cloud streaming service technology capable of capturing only the changed portion with respect to the static image and controlling the still image encoding performed on the captured image at the same time for the image quality to provide an image is urgently required .

Korean Patent Publication No. 2008-0053122, June 12, 2008 (Name: Adaptive Transmission Apparatus of Hierarchically Coded Content and Method Thereof)

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

It is another object of the present invention to improve the speed of providing an image-based cloud streaming service by performing batch still image encoding on images having image quality lower than a certain level to provide images.

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

According to an aspect of the present invention, there is provided a cloud streaming server comprising: a capture unit for capturing a changed image by comparing frames corresponding to an application execution screen received according to a user request; An encoding unit that simultaneously performs still image encoding on the changed image in two encoding methods corresponding to high image quality and low image quality; An encoding controller for performing the still image encoding and checking the number of colors of the changed image and determining whether to stop the still image encoding corresponding to the high image quality based on the number of colors; And a sending unit transmitting the still image-encoded changed image to either the high image quality image or the low image quality image to the terminal so as to display the application execution image on the user terminal, thereby performing an image-based cloud streaming service.

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

At this time, the encoding unit can simultaneously perform still image encoding using any one of a lossy PNG encoding method and a PNG 32-bit encoding method corresponding to the high image quality and a palette PNG encoding method corresponding to the low image quality.

At this time, if the number of colors is equal to or less than the predetermined reference color number, the encoding control unit can stop the still image encoding corresponding to the high image quality using the high quality encoding stop message.

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

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

At this time, the cloud streaming server compares the frames to perform the cloud streaming service based on the video codec, and the image-based cloud streaming service can be performed through the image capturing .

According to another aspect of the present invention, there is provided an image cloud streaming service method using simultaneous encoding, the method comprising: capturing a changed image by comparing frames corresponding to an application execution screen received according to a user request; A still image encoding step of simultaneously encoding the changed image in two encoding methods corresponding to a high image quality and a low image quality; Checking the number of colors of the changed image at the same time as performing the still image encoding and determining whether to stop the still image encoding corresponding to the high image quality based on the number of colors; And performing image-based cloud streaming service by transmitting the still image-encoded changed image to either the high image quality image or the low image quality image to the terminal so as to display the application execution image on the user terminal.

In this case, the performing step may transmit the still image encoded still image encoded high quality image to the terminal when the still image encoding corresponding to the high image quality is performed without interruption.

At this time, the still image encoding step may simultaneously perform still image encoding using either the encoding method of the lossy PNG encoding method corresponding to the high image quality or the PNG 32 bit encoding method, and the palette PNG encoding method corresponding to the low image quality.

In this case, the step of determining whether or not the stopping operation includes a step of generating a high quality encoding stop message when the number of colors is equal to or less than a preset reference color number, and transmitting the high quality encoding stop message to an encoder end, The image encoding can be interrupted.

In this case, when the still image encoding corresponding to the high image quality is interrupted, the performing step may transmit the still image encoded still image with the low image quality to the terminal.

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

In this case, the image cloud streaming service method compares the frames to perform a cloud streaming service based on a video codec, and a section in which the change is small performs the image-based cloud streaming service through the image capture .

According to the present invention, an encoding process is controlled according to the image quality of an image to be provided to a user, thereby reducing a load generated in an image-based cloud streaming service.

In addition, according to the present invention, it is possible to enhance the speed of providing an image-based cloud streaming service by performing batch still image encoding on images having image quality lower than a certain level to provide images.

In addition, the present invention can provide an image-based cloud streaming service in which image quality is ensured to a user by performing still image encoding using a high-quality encoding method according to the image quality of an image to be provided to a user.

In addition, since the present invention displays only a changed image of a frame in a user terminal, the cloud streaming service can be smoothly provided 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 illustrating an example of the cloud streaming server shown in FIG.
FIG. 3 is a diagram illustrating an image-based cloud streaming service process according to the present invention.
FIG. 4 is a view illustrating a process of comparing frames to detect an image to be captured according to the present invention.
5 is a diagram illustrating a method of including color information in a pixel according to the PNG 32 bit method.
6 is a diagram illustrating a method of including color information in a pixel according to a palette PNG method.
7 is a diagram showing an example of a color index generated by the palette PNG method.
8 is a flowchart illustrating an image cloud streaming service method using simultaneous encoding according to an exemplary embodiment of the present invention.
9 is a flowchart illustrating an image cloud streaming service method using simultaneous encoding according to an exemplary embodiment of the present invention.
10 is a flowchart illustrating an image cloud streaming process using simultaneous encoding according to an exemplary embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, detailed description of well-known functions or constructions that may obscure the subject matter of the present invention will be omitted. It should be noted that the same constituent elements are denoted by the same reference numerals as possible throughout the drawings. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

The terms and words used in the present specification and claims should not be construed to be limited to ordinary or dictionary meanings and the inventor is not limited to the concept of terminology for describing his or her invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are described. Therefore, It is to be understood that equivalents and modifications are possible. Also, the terms first, second, etc. are used for describing various components and are used only for the purpose of distinguishing one component from another component, and are not used to define 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, a 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. As shown in FIG.

The cloud streaming server 110 compares the frames corresponding to the application execution screen received according to a user request and captures the changed image. At this time, the current frame and the previous frame among the frames can be compared to capture the changed image.

In addition, the cloud streaming server 110 simultaneously performs still image encoding on the changed image in two encoding methods corresponding to the high image quality and the low image quality, respectively. At this time, still image encoding can be performed simultaneously using either the encoding method of the lossy PNG encoding method corresponding to the high image quality or the PNG 32 bit encoding method, and the palette PNG encoding method corresponding to the low image quality. In this case, the encoding method corresponding to the high image quality may correspond to either the lossy PN encoding method or the PNG 32 bit encoding method.

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

In addition, the cloud streaming server 110 transmits a still image-encoded changed image to either one of the high-definition image quality and the low-quality image to display the application execution screen in the user's terminal devices 120-1 to 120- 120-N to perform an image-based cloud streaming service. In this case, when the still image encoding corresponding to the high image quality is performed without interruption, the still image encoded and changed image can be transmitted to the terminal devices 120-1 to 120-N with high image quality. At this time, if the still image encoding corresponding to the high image quality is interrupted, the still image encoded and changed image can be transmitted to the terminal devices 120-1 to 120-N with a low image quality.

In addition, the cloud streaming server 110 compares frames corresponding to the received application execution screen according to a user request, and performs a cloud streaming service based on a video codec in a section where the variation is large, Image-based cloud streaming service can be performed.

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

Each of the terminal devices 120-1 to 120-N is connected to a communication network and is capable of executing an application based on a cloud computing system. The terminal devices 120-1 to 120-N are not limited to the mobile communication terminal but may be any information communication device, , A fixed terminal, and an IP (Internet Protocol) terminal. Each of the terminal devices 120-1 to 120-N may be a mobile phone, a portable multimedia player (PMP), a mobile Internet device (MID), a smart phone, a desktop, a tablet PC, A mobile terminal having various mobile communication specifications such as a notebook, a netbook, a personal digital assistant (PDA), a smart TV, and an information communication device.

The terminal devices 120-1 to 120-N receive various kinds of information such as numbers and character information, and are inputted with respect to setting various functions and controlling functions of the terminal devices 120-1 to 120-N The signal can be transmitted to the control unit through the input unit. The input unit of the terminal devices 120-1 to 120-N may include at least one of a keypad and a touch pad for generating an input signal according to a user's touch or operation. At this time, the input units of the terminal devices 120-1 to 120-N are configured in the form of one touch panel (or touch screen) together with the display units of the terminal devices 120-1 to 120-N Input and display functions can be performed simultaneously. In addition to the input devices such as a keyboard, a keypad, a mouse, a joystick, etc., the input unit of the terminal devices 120-1 to 120-N may be any type of input device that can be developed in the future. Particularly, the input unit of the terminal devices 120-1 to 120-N according to the present invention can transmit input signals for uploading or downloading contents based on cloud computing to the control units of the terminal devices 120-1 to 120-N have.

In addition, the display unit of the terminal devices 120-1 to 120-N can display information on a series of operation states, operation results, and the like that occur during the performance of the functions of the terminal devices 120-1 to 120-N. The display unit of the terminal devices 120-1 to 120-N may display menus of the terminal devices 120-1 to 120-N and user data input by the user. Here, the display units of the terminal devices 120-1 to 120-N may be a liquid crystal display (LCD), a thin film transistor LCD (TFT-LCD), a light emitting diode (LED) ), An organic light emitting diode (OLED), an organic light emitting diode (AMOLED), an active matrix OLED, a retina display, a flexible display and a three-dimensional display . At this time, when the display units of the terminal apparatuses 120-1 to 120-N are configured as touch screens, the display units of the terminal apparatuses 120-1 to 120- Some or all of the functions of the input unit can be performed. In particular, the display unit of the terminal devices 120-1 to 120-N according to the present invention can display information related to execution of content provided on a cloud computing basis on a screen.

The storage unit of the terminal devices 120-1 to 120-N is a device for storing data, and includes a main storage device and an auxiliary storage device. The storage devices of the terminal devices 120-1 to 120- You can save the application you need. The storage units of the terminal devices 120-1 to 120-N may largely include a program area and a data area. Here, when the terminal devices 120-1 to 120-N activate each function in response to a request from the user, the terminal devices 120-1 to 120-N provide respective functions by executing the corresponding application programs under the control of the controller. In particular, the storage unit of the terminal devices 120-1 to 120-N according to the present invention may include an operating system for booting the terminal devices 120-1 to 120-N, a program for uploading or downloading content on the basis of cloud computing, Can be stored. In addition, the storage unit of the terminal devices 120-1 to 120-N may store information of a content DB storing a plurality of contents and information of the terminal devices 120-1 to 120-N. At this time, the content DB includes execution data for executing the content and attribute information about the content, and content usage information according to the execution of the content can be stored. The information of the terminal devices 120-1 to 120-N may include terminal specification information.

In addition, the communication units of the terminal devices 120-1 to 120-N may perform a function of 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 RF transmitting means for up-converting and amplifying the frequency of the transmitted signal, RF receiving means for low-noise amplifying the received signal and down-converting the frequency have. The communication units 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 the case where the terminal devices 120-1 to 120-N use wireless communication, the wireless communication module is a wireless communication module, a wireless LAN communication module, and a wireless fan communication module Data can be transmitted and received to the cloud streaming server 110 using any one of the modules. The wired communication module is for transmitting / receiving data by wire. The wired communication module may connect to the network 130 through a wired network and transmit / receive data to / from the cloud streaming server 110. That is, the terminal devices 120-1 to 120-N access the network 130 using a wireless communication module or a wired communication module and transmit and receive data to and from the cloud streaming server 110 through the network 130 . In particular, the network 130 according to the present invention can communicate with the cloud streaming server 110 or other terminal devices 120-1 to 120-N to transmit / receive data necessary for uploading or downloading content based on cloud computing .

The control unit of the terminal devices 120-1 to 120-N may be an operating system (OS) and a process unit for driving each configuration. For example, the control unit may include a cloud streaming server 110, When accessing the cloud streaming server 110 through a separate service application, it is possible to control the entire process of executing the service application according to the request of the user, and at the same time, It is possible to control the streaming server 110 to transmit the service use request and control the information of the terminal devices 120-1 to 120-N necessary for user authentication to be transmitted together.

In addition, the control unit of the terminal devices 120-1 to 120-N may execute specific contents stored in the storage units of the terminal devices 120-1 to 120-N at the request of the user. At this time, the control unit may store the content usage history according to the execution of the content as the content usage information.

In addition, the control unit of the terminal devices 120-1 to 120-N may include execution data for executing the content, content information including attribute information on the content, and content usage information, To the streaming server 110 and uploaded. Thereafter, the controller transmits the uploaded content to the cloud streaming server 110, deletes the uploaded content from the storage unit of the terminal devices 120-1 to 120-N according to a request from the user, and transmits the uploaded content to the cloud streaming server 110 The content may be executed through the cloud streaming server 110 and used.

The control unit of the terminal devices 120-1 to 120-N accesses the cloud streaming server 110 to download content from the other terminal devices 120-1 to 120-N and controls the storage to be stored in the storage unit When the content is executed through the cloud streaming server 110, it may be controlled such that the content is executed after receiving only data necessary for execution.

The network 130 provides a path for transferring data between the cloud streaming server 110 and the terminal devices 120-1 to 120-N. The network 130 is a concept that includes both existing networks and future developable networks to be. For example, the network 130 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 objects and mobile objects outside the mobile object, Or a wired / wireless communication network, or a combination of two or more. Meanwhile, the transmission scheme standard of the network 130 is not limited to the existing transmission scheme standard, and may include all transmission scheme standards to be developed in the future. 1, the network used between the cloud streaming server 110 and the terminal devices 120-1 to 120-N may be different from the network used between the terminal devices 120-1 to 120-N And may be the same.

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

2 is a block diagram illustrating an example of the cloud streaming server shown in 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, 260).

The communication unit 210 transmits and receives information related to a plurality of terminals through a communication network such as the network shown in FIG. In particular, the communication unit 210 according to an exemplary embodiment of the present invention may 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, the application execution screen can be received from the cloud streaming server with respect to the cloud streaming service requested by the terminal.

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

The cloud streaming technique based on the video codec can encode all the frames corresponding to the screen on which the application operates. However, when the frame-to-frame change on the screen on which the application is operated is not large, the still-image encoding is performed by capturing only the change area of the changed frame as compared with the previous frame like the image-based cloud streaming technique, It is possible to display the parts except for the change area in the same manner and display only the change area.

At this time, the current frame and the previous frame among the frames can be compared to capture the changed image. For example, if the current frame is compared with the previous frame when the current frame is compared with the previous frame, the changed area of the current frame's screen area can be captured as the changed image. In addition, the size of the captured image may vary depending on the input signal input from the user terminal.

In addition, it is possible to detect intervals in which frames are less changed between frames, and capture changed images in a period where there is little change between frames. For example, it may be inefficient to provide an image-based cloud streaming service because there are a large number of images to be captured with a large number of changes between frames. Accordingly, in such a period, a service can be performed through a cloud streaming technique based on a video codec, and a changed image can be captured to perform an image-based cloud streaming service only in a period where there is little change between frames.

The encoding unit 230 simultaneously performs still image encoding on the changed image using two encoding methods corresponding to the high image quality and the low image quality, respectively.

When the image is encoded for the image-based cloud streaming service in the cloud streaming server 110, the load of the cloud streaming server 110 at the time of encoding, the image quality of the image or the performance of the terminal receiving and rendering the encoded image The encoding method can be determined.

In this case, the PNG format can be used for applying the transparency effect of the image. The encoding method corresponding to the PNG format can be variously used including the PNG 32 bit, the palette PNG, and the lossy PNG.

In the PNG 32-bit encoding method, when the still image is encoded, the image quality is good, but the data size of the image is large, which can cause a large load on the cloud streaming server 110 when encoding. Also, if the bandwidth of the transmission network is low due to the large data size, the transmission rate may decrease.

The palette PNG encoding method is an encoding method called Indexed PNG encoding method or PNG 8 bit encoding method. Since the index method of the small number of colors is used and each pixel is replaced with the color included in the index, the data size of the image is reduced in the still image encoding . Therefore, although the transmission speed can be guaranteed, since the color is represented by 8 bits, deterioration in image quality can be caused when the number of colors is large as in the image including the gradation effect.

In the lossy PNG encoding method, the still image encoding is performed by setting the image quality degradation level in the still image encoding, thereby reducing the image quality at a certain level but also reducing the data size of the image. The Lossy PNG encoding method can be regarded as a middle level between the PNG 32-bit encoding method and the palette PNG encoding method for picture quality and data size.

At this time, the still image encoding can be performed simultaneously with the lossy PNG encoding method corresponding to the high image quality and the palette PNG encoding method corresponding to the low image quality. For example, to improve the speed of the cloud streaming service by default, still images can be encoded for images that have been converted to palette PNG encoding. However, if the changed image is a high-quality image, the quality of the still image-encoded changed image may be seriously degraded by the pallet PNG encoding method.

Therefore, still image encoding can be performed simultaneously with the lossy PNG encoding method that can guarantee an appropriate level of image quality at the same time as the pallet PNG.

In this case, the encoding method corresponding to the high image quality may correspond to either the lossy PN encoding method or the PNG 32 bit encoding method. For example, even if a high-quality image is still-image encoded and streamed according to 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, It may not occur. Accordingly, when still image encoding of a high-quality image is performed, still image encoding can be performed by appropriately using a lossy PNG or PNG 32-bit encoding method according to various environmental information.

The encoding controller 240 performs still image encoding, checks the number of colors of the changed image, and determines whether to stop the still image encoding corresponding to the high image quality based on the number of colors. For example, the number of colors in the changed image can be checked by a method for determining whether the changed image is a high-quality image or a low-quality image. The number of colors may be composed of the number of colors of the pixels constituting the image, the high-quality image may be composed of pixels corresponding to a large number of colors, and the low-quality image may be composed of pixels corresponding to a lower number of colors than high- .

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

At this time, when the number of colors is equal to or less than the preset reference color number, the still image encoding corresponding to the high image quality can be stopped using the high quality encoding stop message. That is, since the changed image is a low-quality image having a small number of colors, even if the still image encoding corresponding to the low-quality image is performed and the streaming is performed, the quality of the changed image may not be deteriorated or decreased.

Accordingly, in order to stop the still image encoding of high quality still being performed, a still image encoding stop message corresponding to a high image quality can be stopped by generating a high quality encoding stop message and transmitting it to the encoding unit 230. [

In addition, if the number of colors exceeds a predetermined number of reference colors, the still image encoding corresponding to the lower quality may be stopped. However, when the still image encoding corresponding to the lower quality is performed, the load of the cloud streaming server 110 does not greatly increase, so the following process may be performed without stopping.

The sending unit 250 transmits the still image-encoded changed image to either one of the high image quality and the low image quality to display an application execution screen on the user's terminal, and performs an image-based cloud streaming service.

The user terminal can render the application execution screen transmitted from the cloud streaming server 110 and display the rendered application execution screen so that the user can view the application execution screen, thereby providing the cloud streaming service.

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

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

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

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

The storage unit 260 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 unit 260 may be configured independently of the cloud streaming server 110 to support a function for the cloud streaming service. At this time, the storage unit 260 may operate as a separate mass storage and may include a control function for performing operations.

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 to perform the cloud streaming service based on the video codec in the part where the change is significant, Image capture enables image-based cloud streaming services.

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 can store information in the memory on which the memory is mounted. In one implementation, the memory is a computer-readable medium. In one implementation, the memory may be a volatile memory unit, and in other embodiments, the memory may be a non-volatile memory unit. In one implementation, 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 any other mass storage device.

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

Referring to FIG. 3, an image-based cloud streaming service may be first performed by a user in a terminal area 315 and a user input may be delivered to an application server area 305.

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

In the cloud streaming server area 300, the changed image is captured in the received application execution screen, and the changed image can be still image encoded using a low-quality pallet PNG encoding scheme and a high-quality lossy PNG encoding scheme.

At this time, in the cloud streaming server area 300, the still image encoding of the two methods is performed, and at the same time, the number of colors of the changed image is checked and the still image encoding stoppage corresponding to the high-quality lossy PNG encoding method is determined based on the number of colors . That is, if the changed image is a high-quality image having a number of colors exceeding the preset reference number of colors as a result of checking the number of colors of the changed image, the still image encoding corresponding to the lossy PN encoding method can be continuously performed without interruption. However, if the changed image is a low-quality image having a number of colors equal to or less than a preset reference number of colors, the still image encoding corresponding to the lossy PNG encoding method can be stopped because the service can be performed only by the still image encoding corresponding to the pallet PNG encoding method .

By including the process of stopping the still image encoding corresponding to the lossy PNG encoding method according to the image quality of the changed image, the load in the cloud streaming server area 300, which may be unnecessarily generated, can be reduced.

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

For example, if the still image encoding of the lossyPNG encoding scheme is interrupted at the encoder end, the changed image can be recognized as a low quality image and stream the still image encoded changed image in the palette PNG encoding scheme. Also, if the still image encoding of the lossy PN encoding method is not interrupted at the encoder end, the changed image can be recognized as a high quality image and the still image encoded changed image can be streamed in the lossy PN encoding method. If the still image encoding of the lossyPNG encoding scheme is not interrupted at the encoder, but the still image encoded modified image is not present in the lossy PNG encoding scheme, it is determined that an error has occurred in the cloud streaming server and the encoding of the corresponding changed image is performed again You may.

Thereafter, the still image encoded and transformed image transmitted from the cloud streaming server area 300 is rendered in the terminal area 315 and displayed to the user.

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

FIG. 4 is a view illustrating a process of comparing frames to detect an image to be captured according to the present invention.

Referring to FIG. 4, in the process of comparing the frames according to the present invention and detecting an image to be captured, the user can first obtain frames in a part where the screen changes little on the application execution screen according to the user's request.

At this time, it may be more efficient to provide the application execution screen to the user through the cloud streaming service based on the video codec for the part where the screen changes much.

Thereafter, the current frame 420 and the previous frame 410 among the frames of the small change portion can be compared. For example, when comparing the current frame 420 shown in FIG. 4 with the previous frame 410, there is no change in the A area of the two frames, but the B area of the previous frame 410 is B ' As shown in Fig.

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

When the current frame 420 and the previous frame 410 are compared, if a plurality of regions are identified as the changed region 430, one region including all the changed regions is referred to as a changed region 430 ) And capture it. In addition, it is also possible to recognize various changed areas as the changed areas 430 and to capture a plurality of changed areas 430 to perform an image-based cloud streaming service.

5 is a diagram illustrating a method of including color information in a pixel according to the PNG 32 bit method.

Referring to FIG. 5, a method of including color information in a pixel according to the PNG 32-bit method includes the steps of storing pixels corresponding to R (Red), G (Green), and B (Blue) can do. Thus, one pixel 510 has a data size of 3 Bytes, and the entire image can have a data size as much as the number of pixels included in the image multiplied by a value of 3 Bytes.

In this case, in the case of the PNG 32-bit method, it is possible to have a data size of 32 bits per one pixel, that is, a data size of 4 bytes. In this case, 3Byte of 4Byte may be RGB color data as described above, and the remaining 1Byte may be data for representing transparent information for transparency effect.

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

Referring to FIG. 6, in a method of including color information in a pixel according to the pallet PNG method, the pixel 610 may include corresponding information of the color index as 1-byte data. Thus, one pixel 610 has a data size of 1 Byte, and the entire image can have a data size as much as the number of pixels included in the image multiplied by a value of 1 Byte.

The reason why the palette PNG method is called as the PNG 8 bit method or the Indexed PNG method is that the data size of one pixel 610 is 1 byte corresponding to 8 bits and the color value is represented through the color index.

Accordingly, when the cloud streaming service is performed, when the cloud streaming server encodes the image in the palette PNG method, the size of the data can be reduced to one-fourth of that in the PNG 32-bit method shown in FIG. However, since the number of colors that can be represented by the pixel 610 of the palette PNG system is limited to 1 Byte, the image quality of the image may be degraded.

7 is a diagram showing an example of a color index generated by the palette PNG method.

Referring to FIG. 7, since the color index 710 generated by the palette PNG method has a data size of 1 Byte, a pixel of the palette PNG method can include 256 pieces of color information corresponding to 8 bits, that is, have.

7, the color corresponding to the 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 pallet number 1 and the color corresponding to pallet number 2 are respectively the color having values of Red '127', Green '127', and Blue '127' in the RGB color code and Red '255' Green '255', and Blue '255'.

The color index 710, which is composed of a total of 256 colors using the values of the RGB color codes, can be configured based on the colors constituting the captured changed image by comparing the frames of the application execution screen. For example, if the color constituting the changed image is blue, the color index 710 may include many blue-based colors.

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

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

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

The cloud streaming technique based on the video codec can encode all the frames corresponding to the screen on which the application operates. However, when the frame-to-frame change on the screen on which the application is operated is not large, the still-image encoding is performed by capturing only the change area of the changed frame as compared with the previous frame like the image-based cloud streaming technique, It is possible to display the parts except for the change area in the same manner and display only the change area.

At this time, the current frame and the previous frame among the frames can be compared to capture the changed image. For example, if the current frame is compared with the previous frame when the current frame is compared with the previous frame, the changed area of the current frame's screen area can be captured as the changed image. In addition, the size of the captured image may vary depending on the input signal input from the user terminal.

In addition, it is possible to detect intervals in which frames are less changed between frames, and capture changed images in a period where there is little change between frames. For example, it may be inefficient to provide an image-based cloud streaming service because there are a large number of images to be captured with a large number of changes between frames. Accordingly, in such a period, a service can be performed through a cloud streaming technique based on a video codec, and a changed image can be captured to perform an image-based cloud streaming service only in a period where there is little change between frames.

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

In the cloud streaming server, when encoding an image for an image-based cloud streaming service, the encoding method is selected considering the load on the cloud streaming server during encoding, the image quality of the image, or the performance of the terminal receiving and rendering the encoded image. You can decide.

In this case, the PNG format can be used for applying the transparency effect of the image. The encoding method corresponding to the PNG format can be variously used including the PNG 32 bit, the palette PNG, and the lossy PNG.

The PNG 32-bit encoding method has a good image quality in still image encoding, but the data size of the image is large, which can cause a large load on the cloud streaming server when encoding. Also, if the bandwidth of the transmission network is low due to the large data size, the transmission rate may decrease.

The palette PNG encoding method is an encoding method called Indexed PNG encoding method or PNG 8 bit encoding method. Since the index method of the small number of colors is used and each pixel is replaced with the color included in the index, the data size of the image is reduced in the still image encoding . Therefore, although the transmission speed can be guaranteed, since the color is represented by 8 bits, deterioration in image quality can be caused when the number of colors is large as in the image including the gradation effect.

In the lossy PNG encoding method, the still image encoding is performed by setting the image quality degradation level in the still image encoding, thereby reducing the image quality at a certain level but also reducing the data size of the image. The Lossy PNG encoding method can be regarded as a middle level between the PNG 32-bit encoding method and the palette PNG encoding method for picture quality and data size.

At this time, the still image encoding can be performed simultaneously with the lossy PNG encoding method corresponding to the high image quality and the palette PNG encoding method corresponding to the low image quality. For example, to improve the speed of the cloud streaming service by default, still images can be encoded for images that have been converted to palette PNG encoding. However, if the changed image is a high-quality image, the quality of the still image-encoded changed image may be seriously degraded by the pallet PNG encoding method.

Therefore, still image encoding can be performed simultaneously with the lossy PNG encoding method that can guarantee an appropriate level of image quality at the same time as the pallet PNG.

In this case, the encoding method corresponding to the high image quality may correspond to either the lossy PN encoding method or the PNG 32 bit encoding method. For example, according to 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-quality image is still-image encoded and streamed using the PNG 32-bit encoding method. Accordingly, when still image encoding of a high-quality image is performed, still image encoding can be performed by appropriately using a lossy PNG or PNG 32-bit encoding method according to various environmental information.

Also, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention performs still image encoding, checks the number of colors of the changed image, and stops the still image encoding corresponding to the high image quality based on the number of colors (S830). For example, the number of colors in the changed image can be checked by a method for determining whether the changed image is a high-quality image or a low-quality image. The number of colors may be composed of the number of colors of the pixels constituting the image, the high-quality image may be composed of pixels corresponding to a large number of colors, and the low-quality image may be composed of pixels corresponding to a lower number of colors than high- .

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

At this time, when the number of colors is equal to or less than the preset reference color number, the still image encoding corresponding to the high image quality can be stopped using the high quality encoding stop message. That is, since the changed image is a low-quality image having a small number of colors, even if the still image encoding corresponding to the low-quality image is performed and the streaming is performed, the quality of the changed image may not be deteriorated or decreased.

Therefore, in order to stop the still image encoding of high image quality which is being performed unnecessarily, a still image encoding corresponding to high image quality can be stopped by generating a high quality encoding stop message and transmitting it to the encoder end.

In addition, if the number of colors exceeds a predetermined number of reference colors, the still image encoding corresponding to the lower quality may be stopped. However, when performing still image encoding corresponding to a lower quality image, the load on the cloud streaming server does not significantly increase, so the following process may be performed without interruption.

Also, an image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention transmits a still image-encoded changed image to a terminal in either a high image quality or a low image quality to display an application execution screen in a user terminal, (S840). ≪ / RTI >

The user terminal can render the application execution screen transmitted from the cloud streaming server and display the rendered application execution screen so that the user can view the cloud streaming service.

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

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

Also, even if the still image encoding corresponding to the high image quality is not interrupted, there may be a still image encoded changed image with a low image quality with the still image encoded changed image with high image quality. At this time, the still image-encoded changed image with low image quality may be deleted, or may be stored in the cache memory of the cloud streaming server according to the frequency with which the corresponding changed image is requested to the user.

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

Although not shown in FIG. 8, the image cloud streaming service method using simultaneous encoding according to an embodiment of the present invention transmits and receives information related to a plurality of terminals through a communication network such as the network shown in FIG. 1 . In particular, a request for the cloud streaming service can be received from the terminal, and an execution screen of the application corresponding to the cloud streaming service requested by the terminal can be provided to the terminal.

At this time, the application execution screen can be received from the cloud streaming server with respect to 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 cloud streaming service process according to an embodiment of the present invention, as described above.

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

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

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

At this time, the cloud streaming server can receive an application execution screen from the application server through a communication network such as the network shown in Fig.

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

At this time, the current frame and the previous frame among the frames can be compared to capture the changed image.

In addition, it is possible to detect intervals in which frames are less changed between frames, and capture changed images in a period where there is little change between frames. In this case, it is inefficient to provide an image-based cloud streaming service because a large number of images have a large number of captured images. Accordingly, in such a period, a service can be performed through a cloud streaming technique based on a video codec, and a changed image can be captured to perform an image-based cloud streaming service only in a period where there is little change between frames.

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

In this case, a PNG format can be used to apply a transparent effect of an image in still image encoding. The encoding method corresponding to the PNG format can be variously used including PNG 32 bit, palette PNG, and lossy PNG.

At this time, the still image encoding can be performed simultaneously with the lossy PNG encoding method corresponding to the high image quality and the palette PNG encoding method corresponding to the low image quality.

In addition, the encoding method corresponding to the high image quality may correspond to either the lossy PN encoding method or the PNG 32 bit encoding method. For example, according to 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-quality image is still-image encoded and streamed using the PNG 32-bit encoding method. Accordingly, when still image encoding of a high-quality image is performed, still image encoding can be performed by appropriately using a lossy PNG or PNG 32-bit 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 a preset reference color number (S935).

As a result of the determination in step S935, if it is less than the predetermined reference color number, the still image encoding corresponding to the high image quality is interrupted (S940).

In this case, the number of colors may be composed of the number of colors of the pixels constituting the image, the high-quality image may be composed of pixels corresponding to a large number of colors, and the low-quality image may be composed of pixels ≪ / RTI >

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

At this time, the still image encoding corresponding to the high image quality can be stopped using the high quality encoding stop message.

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

If it is determined in step S945 that the still image encoding corresponding to the high image quality has been interrupted, the still image encoded low image quality changed image is transmitted to the terminal in step S950.

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

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

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

In addition, the image cloud streaming method using simultaneous encoding according to an embodiment of the present invention performs a cloud streaming service based on a video codec by comparing frames of an application execution screen received according to a user request, The image-based cloud streaming service can be performed through image capture.

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

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

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

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

At this time, the cloud streaming server 110 can receive the application execution screen through the communication unit. The communication unit can transmit / receive information related to a plurality of terminals through a network, and can transmit / receive application information according to 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 compares frames of the received application execution screen to capture the changed image (S1008). At this time, frames can be compared and a video streaming service based on a video codec can be performed for a section having many changed parts.

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

At this time, the encoding unit can simultaneously perform still image encoding using an encoding method corresponding to the low image quality and the high image quality.

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

For example, when the number of colors of the changed image is checked to be less than a preset reference, the changed image is determined to be a low-quality image, and a high-quality encoding stop message is transmitted (S1016) to stop still image encoding corresponding to high image quality.

In addition, when the number of colors of the changed image is checked to exceed the preset reference, the changed image is determined to be a high-quality image, and the still image encoding corresponding to the high image quality can be continuously performed without interruption.

Thereafter, the still image encoding is completed in two ways according to whether the encoding control unit is stopped or the still image encoding is completed in the encoding method corresponding to the low image quality (S1018).

 Thereafter, the sending unit of the cloud streaming server 110 checks whether the still image encoding corresponding to the high image quality is interrupted (S1020).

At this time, the reason for confirming whether or not the still image encoding corresponding to the high image quality is stopped is to determine the image quality of the still image-encoded changed image to be transmitted to the terminal 120-1 by the sending unit.

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 the still image encoding corresponding to the high image quality is stopped as a result of the confirmation, the changed image can be recognized as a low quality image and the still image encoded changed image can be transmitted with low image quality. Also, if the still image encoding corresponding to the high image quality is not interrupted, the changed image can be recognized as a high-quality image and the still image-encoded changed image can be transmitted with high image quality.

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

At this time, since only the changed image is rendered on the application execution screen, the difference in the rendering speed due to the performance difference of the terminal 120-1 can be reduced. That is, rendering can be performed smoothly even in a low-performance old terminal.

After that, the terminal 120-1 displays an application execution screen to the user (S1026), and can 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 program instructions 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, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Includes all types of hardware devices that are specially configured to store and execute magneto-optical media and program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions may include machine language code such as those generated by a compiler, as well as high-level language code that may be executed by a computer using an interpreter or the like. Such a hardware device 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, the image cloud streaming service method using simultaneous encoding, and the apparatus therefor according to the present invention are not limited to the configuration and method of the embodiments described above, The examples may be constructed by selectively combining all or a part of each embodiment so that various modifications can be made.

According to an embodiment of the present invention, frames corresponding to a received application execution screen are compared according to a user request to capture a changed image, and still image encoding is performed on the changed image in two encoding methods corresponding to high image quality and low image quality, The number of colors of the changed image is checked and it is judged whether or not the still image encoding corresponding to the high image quality is stopped based on the number of colors. In order to display the application execution screen in the terminal of the user, The image-encoded changed image can be transmitted to the terminal and the image-based cloud streaming service can be performed. In addition, a cloud streaming service, which provides both image quality and speed of service provided by providing a service by performing batch encoding of images having image quality lower than a certain level during service and encoding using high-quality encoding method for high- Can be provided.

110: Cloud streaming servers 120-1 to 120-N:
130: Network 210:
220: Capture unit 230: Encode unit
240: encoding control unit 250:
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 (10)

A capture unit for capturing a changed image by comparing frames corresponding to a received application execution screen according to a user request;
An encoding unit that simultaneously performs still image encoding on the changed image in two encoding methods corresponding to high image quality and low image quality;
An encoding controller for performing the still image encoding and checking the number of colors of the changed image and determining whether to stop the still image encoding corresponding to the high image quality based on the number of colors; And
And a transmitting unit for transmitting the still image-encoded changed image to the terminal in either the high image quality or the low image quality to display the application execution screen on the user's terminal to perform an image-based cloud streaming service,
Wherein the server comprises: The method according to claim 1,
The sending unit
And transmits the still image-encoded changed image to the terminal in the high image quality when the still image encoding corresponding to the high image quality is performed without interruption. The method of claim 2,
The encoding unit
Wherein the still image encoding is performed simultaneously with either the encoding method of the lossy PN encoding method corresponding to the high image quality or the PNG 32 bit encoding method and the palette PNG encoding method corresponding to the low image quality. The method of claim 3,
The encoding control unit
And stops the still image encoding corresponding to the high image quality using the high image quality encoding stop message if the color number is equal to or less than the predetermined reference color number. The method of claim 4,
The sending unit
Wherein when the still image encoding corresponding to the high image quality is interrupted, the server transmits the still image encoded still image encoded image to the terminal with the low image quality. The method according to claim 1,
The capture unit
Wherein the server compares the current frame and the previous frame among the frames and captures the changed image. The method according to claim 1,
The cloud streaming server
Wherein the controller is configured to perform a cloud streaming service based on a video codec and to perform the image-based cloud streaming service through the image capture. Capturing a changed image by comparing frames corresponding to a received application execution screen according to a user request;
A still image encoding step of simultaneously encoding the changed image in two encoding methods corresponding to a high image quality and a low image quality;
Checking the number of colors of the changed image at the same time as performing the still image encoding and determining whether to stop the still image encoding corresponding to the high image quality based on the number of colors; And
Performing image-based cloud streaming service by transmitting the still image-encoded changed image to either one of the high image quality and the low image quality to the terminal so as to display the application execution image on the user terminal
The method of claim 1, further comprising: The method of claim 8,
The step of performing
When the still image encoding corresponding to the high image quality is performed without interruption, transmits the still image encoded still image encoded image to the terminal with the high image quality. The method of claim 9,
The step of determining whether to stop
Generating a high quality encoding interruption message if the color number is less than or equal to a preset reference number of colors,
And transmitting the high quality encoding stop message to the encoder end to stop the still image encoding corresponding to the high image quality.

Images