Patent Publication Number: US-2016232707-A1

Title: Image processing method and apparatus, and computer device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The application is a continuation application of International Application PCT/CN2015/071225, entitled “IMAGE PROCESSING METHOD AND APPARATUS, AND COMPUTER DEVICE”, and filed on Jan. 21, 2015, which claims priority to Chinese Patent Application No. 201410030054.2, entitled “IMAGE PROCESSING METHOD AND APPARATUS, AND COMPUTER DEVICE” filed on Jan. 22, 2014, with the Chinese State Intellectual Property Office, both of which are incorporated herein by reference in their entirety. 
    
    
     FIELD 
     Embodiments of the present invention relate to the field of image processing technologies, and in particular, to an image processing method and apparatus, and a computer device. 
     BACKGROUND 
     Nowadays, network games are flourishing, and people have an increasingly higher requirement for the sense of reality of a scene in a game. Ambient occlusion (AO) is an essential part in a global illumination (GI) technology, and the AO describes an occlusion value between each point on the surface of an object and another object in a scene. Generally, an illumination value of light radiating on the surface of the object is attenuated by using the AO, so as to generate a shadow to enhance a layering sense of a space, enhance the sense of reality of the scene, and enhance artistry of a picture. 
     However, in a process of game development, the inventor of the present disclosure finds that, most mainstream AO map baking software on the market is based on a central processing unit (CPU), but efficiency of processing image data by the CPU is low; as a result, efficiency of AO map baking is very low, and generally, it takes several hours to bake one AO map; and some baking software may enable the CPU to execute one part of the processing process, and enable a graphic processing unit (GPU) to execute the other part of the processing process, but an algorithm involved in such baking software is always very complex, and finally, a problem that image processing efficiency is low is still caused. Therefore, it is necessary to provide a new method to solve the foregoing problem. 
     SUMMARY 
     Embodiments of the present invention provide an image processing method and apparatus, and a computer device, which can improve image processing efficiency. The technical solutions are described as follows: 
     According to a first aspect, an image processing method is provided, where the image processing method includes: receiving, by a GPU, information, which is sent by a CPU, about a scene within a preset range around a to-be-rendered target object; rendering, by the GPU, the scene to obtain scene depth parameters, where the scene is obtained through shooting by a camera located at a ray light source; rendering, by the GPU, the to-be-rendered target object to obtain rendering depth parameters, where the to-be-rendered target object is obtained through shooting by a camera not located at a ray light source; calculating, by the GPU, AO maps of the to-be-rendered target object in directions of ray light sources according to the scene depth parameters and the rendering depth parameters; and overlaying, by the GPU, the AO maps in the directions of the ray light sources, to obtain an output image. 
     According to a second aspect, an image processing apparatus is provided, where the image processing apparatus includes: a receiving unit, that receives information, which is sent by a CPU, about a scene within a preset range around a to-be-rendered target object; a rendering processing unit, that renders the scene to obtain scene depth parameters, where the scene is obtained through shooting by a camera located at a ray light source; and renders the to-be-rendered target object to obtain rendering depth parameters, where the to-be-rendered target object is obtained through shooting by a camera not located at a ray light source; a map generating unit, that calculates AO maps of the to-be-rendered target object in directions of ray light sources according to the scene depth parameters and the rendering depth parameters; and an output processing unit, that overlays the AO maps in the directions of the ray light sources, to obtain an output image. 
     According to a third aspect, a computer device is provided, where the computer device includes a CPU and a GPU, where the CPU determines ray points that use a to-be-rendered target object as a center and are distributed in a spherical shape or a semispherical shape, and establishes, at a position of each ray point, a ray light source that radiates light towards the to-be-rendered target object; and the GPU receives information, which is sent by the CPU, about a scene within a preset range around a to-be-rendered target object; renders the scene to obtain scene depth parameters, where the scene is obtained through shooting by a camera located at a ray light source; renders the to-be-rendered target object to obtain rendering depth parameters, where the to-be-rendered target object is obtained through shooting by a camera not located at a ray light source; calculate AO maps of the to-be-rendered target object in directions of ray light sources according to the scene depth parameters and the rendering depth parameters; and overlays the AO maps in the directions of the ray light sources, to obtain an output image. 
     It may be seen from the foregoing technical solutions that, the embodiments of the present invention have following advantages: 
     In the embodiments of the present invention, a GPU receives information, which is sent by a CPU, about a scene within a preset range around a to-be-rendered target object; the GPU renders the received scene to obtain scene depth parameters; the GPU renders the to-be-rendered target object to obtain rendering depth parameters; the GPU calculates AO maps of the to-be-rendered target object in directions of ray light sources according to the scene depth parameters and the rendering depth parameters; and the GPU overlays the AO maps in the directions of the ray light sources, to obtain an output image. In the embodiments of the present invention, AO maps of a to-be-rendered target object in directions of ray light sources can be calculated only according to scene depth parameters and rendering depth parameters, and an output image can be obtained by simply overlaying the AO maps in the directions of the ray light sources, which therefore avoids a complex calculation process in the prior art; and these image calculation and processing processes are completed by a GPU, and a powerful capability of the GPU for processing image data is utilized, which improves image processing efficiency. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To describe the technical solutions of the embodiments of the present invention or the prior art more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments or the prior art. Apparently, the accompanying drawings in the following description show some embodiments of the present invention, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts. 
         FIG. 1  is a schematic diagram of an embodiment of an image processing method according to the present disclosure; 
         FIG. 2  is a schematic diagram of another embodiment of an image processing method according to the present disclosure; 
         FIG. 3  is a schematic diagram of an embodiment of an image processing apparatus according to the present disclosure; 
         FIG. 4  is a schematic diagram of another embodiment of an image processing apparatus according to the present disclosure; 
         FIG. 5  is a schematic diagram of an embodiment of a computer device according to the present disclosure; 
         FIG. 6  is an output image on which a Gamma correction is not performed; and 
         FIG. 7  is an output image on which a Gamma correction is performed. 
     
    
    
     DETAILED DESCRIPTION 
     To make the objectives, technical solutions, and advantages of the present disclosure more comprehensible, the following further describes the embodiments of the present disclosure in detail with reference to the accompanying drawings. Apparently, the described embodiments are merely some rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present disclosure. 
     Embodiments of the present invention provide an image processing method and apparatus, and a computer device, which can improve image processing efficiency. 
     Referring to  FIG. 1 ,  FIG. 1  is a schematic diagram of an embodiment of an image processing method according to the present disclosure. The image processing method in this embodiment includes: 
       101 : A GPU receives information, which is sent by a CPU, about a scene within a preset range around a to-be-rendered target object. 
     In this embodiment, a model of the to-be-rendered target object is established in the CPU, ray light sources are set, and the CPU shoots the to-be-rendered target object by using a simulated camera located at a ray light source, to obtain the information about the scene within the preset range around the to-be-rendered target object, where the preset range may be preset in the CPU according to an actual need, and the obtained scene may include the to-be-rendered target object and another object, terrain, or the like. The CPU sends the obtained information about the scene within the preset range around the to-be-rendered target object to the GPU, so that the GPU performs further processing. 
       102 : The GPU renders the received scene to obtain scene depth parameters. 
     The GPU receives the information, which is sent by the CPU, about the scene within the preset range around the to-be-rendered target object, and renders the received scene to obtain the scene depth parameters. 
       103 : The GPU renders the to-be-rendered target object to obtain rendering depth parameters. 
     The GPU shoots the to-be-rendered target object separately by utilizing a camera not located at a ray light source, and renders the to-be-rendered target object to obtain the rendering depth parameters. When the GPU shoots the to-be-rendered target object by utilizing the camera not located at a ray light source, a selected shooting angle needs to enable the entire to-be-rendered target object to be shot. 
       104 : The GPU calculates AO maps of the to-be-rendered target object in directions of ray light sources according to the scene depth parameters and the rendering depth parameters. 
     In a specific implementation, there may be multiple ray light sources, and the GPU calculates the AO maps of the to-be-rendered target object in the directions of the ray light sources according to a scene depth parameter and a rendering depth parameter of the to-be-rendered target object in a direction of each ray light source. 
       105 : The GPU overlays the AO maps in the directions of the ray light sources, to obtain an output image. 
     In this embodiment, AO maps of a to-be-rendered target object in directions of ray light sources can be calculated only according to scene depth parameters and rendering depth parameters, and an output image can be obtained by simply overlaying the AO maps in the directions of the ray light sources, which avoids a complex calculation process in the prior art; and these image calculation and processing processes are completed by a GPU, and a powerful capability of the GPU for processing image data is utilized, which improves image processing efficiency. 
     For ease of understanding, the following describes the image processing method in this embodiment of the present invention by using a specific embodiment. Referring to  FIG. 2 , the image processing method in this embodiment includes: 
       201 : A CPU determines ray points that use a to-be-rendered target object as a center and are distributed in a spherical shape or a semispherical shape. 
     In this embodiment, a model of the to-be-rendered target object is established in the CPU, and then the CPU determines the ray points that use the to-be-rendered target object as the center and are evenly distributed in the spherical shape or the semispherical shape. 
       202 : The CPU establishes, at a position of each ray point, a ray light source that radiates light towards the to-be-rendered target object. 
     The CPU establishes, at the position of each ray point, the ray light source, where the ray light source radiates light towards the to-be-rendered target object. Preferably, the number of ray light sources is 900. 
     The CPU shoots the to-be-rendered target object by using a simulated camera located at a ray light source, to obtain information about a scene within a preset range around the to-be-rendered target object, where the preset range may be preset in the CPU according to an actual need, a manner in which the camera shoots the to-be-rendered target object may be a parallel projection matrix manner, and the obtained scene may include the to-be-rendered target object and another object, terrain, or the like. 
     To ensure the accuracy of image drawing, the CPU may filter out dynamic objects in the obtained scene within the preset range around the to-be-rendered target object, where these dynamic objects are, for example, a particle and an animation with a skeleton, and send information about the scene within the preset range around the to-be-rendered target object after the filtration to the GPU, so that the GPU perform further processing. 
     Specifically, the CPU may send the obtained information about the scene to the GPU by utilizing algorithms such as a quadtree, an octree, and a Jiugong. In addition, the information sent to the GPU may further include relevant parameters of the camera at the ray light source, for example, a vision matrix, a projection matrix, and a lens position. 
       203 : A GPU receives information, which is sent by the CPU, about a scene within a preset range around a to-be-rendered target object. 
     The scene received by the GPU is obtained through shooting by the camera at the ray light source. 
       204 : The GPU renders the received scene to obtain scene depth parameters. 
     The GPU renders the received scene to obtain a scene depth image, where the scene depth image stores a scene depth parameter of each pixel point in the scene shot by the camera at the ray light source, that is, also includes a scene depth parameter of each pixel point of the to-be-rendered target object. 
       205 : The GPU renders the to-be-rendered target object to obtain rendering depth parameters. 
     The to-be-rendered target object is obtained through shooting by a camera not located at a ray light source, where the camera may shoot the to-be-rendered target object separately in a parallel projection manner, and a selected shooting angle needs to enable the entire to-be-rendered target object to be shot. 
     The GPU renders the to-be-rendered target object, and obtains a rendering depth image after the rendering, obtains a vertex coordinate of the to-be-rendered target object from the rendering depth image, and multiplies the vertex coordinate of the to-be-rendered target object by a world coordinate matrix, and then by vision matrixes and projection matrixes of cameras located at the ray light sources, to obtain the rendering depth parameters of the to-be-rendered target object. The rendering depth parameters of the to-be-rendered target object include a rendering depth parameter of each pixel point of the to-be-rendered target object. 
       206 : For each ray light source, the GPU calculates an AO value of each pixel point in a direction of the ray light source according to a scene depth parameter and a rendering depth parameter of each pixel point of the to-be-rendered target object. 
     For each ray light source, the GPU obtains a scene depth parameter corresponding to the to-be-rendered target object shot by the camera at the ray light source, and the rendering depth parameter of the to-be-rendered target object shot by the camera not located at any ray light source, and calculates the AO value of each pixel point in the direction of the ray light source according to the scene depth parameter and the rendering depth parameter of each pixel point of the to-be-rendered target object, which is specifically as follows: 
     For a pixel point, the GPU compares a rendering depth parameter of the pixel point with a scene depth parameter of the pixel point, and determines, when the rendering depth parameter is greater than the scene depth parameter, that a shadow value of the pixel point is 1; and determines, when the rendering depth parameter of the pixel point is less than or equal to the scene depth parameter, that the shadow value of the pixel point is 0. 
     The GPU multiplies the shadow value of the pixel point by a weight coefficient to obtain an AO value of the pixel point in the direction of the ray light source, where the weight coefficient includes a dot product of an illumination direction of the ray light source and a normal direction of the pixel point, and a reciprocal of a total number of the ray light sources, for example, when the number of the ray light sources is 900, the reciprocal of the total number of the ray light sources is 1/900. 
     In addition, to ensure calculation accuracy for the AO value of each the pixel point, the foregoing AO value obtained through calculation may be further multiplied by a preset experience coefficient, where the experience coefficient is measured according to an experiment, and may be 0.15. 
       207 : The GPU overlays the AO value of each pixel point to obtain an AO map of the to-be-rendered target object in the direction of the ray light source. 
     The GPU overlays the AO value of each pixel point to obtain the AO value of the to-be-rendered target object, and draws the AO map of the to-be-rendered target object in the direction of the ray light source according to the AO value of the to-be-rendered target object. 
       208 : The GPU calculates AO maps of the to-be-rendered target object in directions of ray light sources. 
     By analogy, the GPU may obtain an AO map of the to-be-rendered target object in a direction of each ray light source according to the foregoing method. 
       209 : The GPU overlays the AO maps in the directions of the ray light sources, to obtain an output image. 
     A black border may be generated on the output image due to sawteeth and texture pixel overflowing. The black border generated due to the sawteeth may be processed by using “percentage progressive filtration” of a shadow, and for each pixel, pixels above, below, to the left of, and to the right of this pixel, and this pixel itself are averaged. The black border generated due to the pixel overflowing may be solved by expanding effective pixels. Specifically, whether a current pixel is ineffective may be determined in a pixel shader. If the current pixel is ineffective, 8 surrounding pixels are sampled, and effective pixels thereof are added up, an average value of the effective pixels is obtained, the average value is used as a shadow value of the current pixel, and the current pixel is set to be effective. In this way, expansion of one pixel for the output image to prevent sampling from crossing a boundary is implemented. 
       210 : The GPU performs a Gamma correction on the output image and outputs the output image. 
     The GPU performs the Gamma correction on the output image, that is, the GPU pastes the output image onto the model of the to-be-rendered target object for displaying, and adjusts a display effect of the output image by using a color chart, to solve a problem that a scene dims as a whole because AO is added to the scene. 
     In this embodiment, AO maps of a to-be-rendered target object in directions of ray light sources can be calculated only according to scene depth parameters and rendering depth parameters, and an output image can be obtained by simply overlaying the AO maps in the directions of the ray light sources, which avoids a complex calculation process in the prior art; and these image calculation and processing processes are completed by a GPU, and a powerful capability of the GPU for processing image data is utilized, which improves image processing efficiency. 
     The following describes an image processing apparatus provided by an embodiment of the present invention. Referring to  FIG. 3 , the image processing apparatus  300  includes: 
     a receiving unit  301 , that receives information, which is sent by a CPU, about a scene within a preset range around a to-be-rendered target object; 
     a rendering processing unit  302 , that renders the received scene to obtain scene depth parameters, where the scene is obtained through shooting by a camera located at a ray light source; and renders the to-be-rendered target object to obtain rendering depth parameters, where the to-be-rendered target object is obtained through shooting by a camera not located at a ray light source; 
     a map generating unit  303 , that calculates AO maps of the to-be-rendered target object in directions of ray light sources according to the scene depth parameters and the rendering depth parameters; and 
     an output processing unit  304 , that overlays the AO maps in the directions of the ray light sources, to obtain an output image. 
     To further understand the technical solutions of the present disclosure, the following describes a manner in which the units in the image processing apparatus  300  in this embodiment interact with each other, which is specifically as follows: 
     In this embodiment, a model of the to-be-rendered target object is established in the CPU, ray light sources are set, and the CPU shoots the to-be-rendered target object by using a simulated camera located at a ray light source, to obtain the information about the scene within the preset range around the to-be-rendered target object, where the preset range may be preset in the CPU according to an actual need, and the obtained scene may include the to-be-rendered target object and another object, terrain, or the like. The CPU sends the obtained information about the scene within the preset range around the to-be-rendered target object to the image processing apparatus, and the receiving unit  301  receives the information, which is sent by the CPU, about the scene within the preset range around the to-be-rendered target object. 
     The rendering processing unit  302  renders the scene received by the receiving unit  301 , to obtain the scene depth parameters, where the scene received by the rendering processing unit  302  is obtained through shooting by the camera located at the ray light source, and renders the to-be-rendered target object to the obtain rendering depth parameters, where the to-be-rendered target object is obtained through shooting by the camera not located at a ray light source. When the to-be-rendered target object is shot by utilizing the camera not located at a ray light source, a selected shooting angle needs to enable the entire to-be-rendered target object to be shot. 
     The map generating unit  303  calculates the AO maps of the to-be-rendered target object in the directions of the ray light sources according to the scene depth parameters and the rendering depth parameters obtained by the rendering processing unit  302 . In a specific implementation, there may be multiple ray light sources, and the map generating unit  303  calculates the AO maps of the to-be-rendered target object in the directions of the ray light sources according to a scene depth parameter and a rendering depth parameter of the to-be-rendered target object in a direction of each ray light source. 
     The output processing unit  304  overlays the AO maps in the directions of the ray light sources, which are generated by the map generating unit  303 , to obtain the output image. 
     In this embodiment, the map generating unit can calculate AO maps of a to-be-rendered target object in directions of ray light sources only according to scene depth parameters and rendering depth parameters, and the output processing unit can obtain an output image by simply overlaying the AO maps in the directions of the ray light sources, which avoids a complex calculation process in the prior art; and an image data processing capability that the image processing apparatus in this embodiment has is more powerful than an image data processing capability of a CPU, which improves image processing efficiency. 
     For ease of understanding, the following further describes an image processing apparatus provided by an embodiment of the present invention. Referring to  FIG. 4 , the image processing apparatus  400  includes: 
     a receiving unit  401 , that receives information, which is sent by a CPU, about a scene within a preset range around a to-be-rendered target object; 
     a rendering processing unit  402 , that renders the received scene to obtain scene depth parameters, where the scene is obtained through shooting by a camera located at a ray light source; and renders the to-be-rendered target object to obtain rendering depth parameters, where the to-be-rendered target object is obtained through shooting by a camera not located at a ray light source; 
     a map generating unit  403 , that calculates AO maps of the to-be-rendered target object in directions of ray light sources according to the scene depth parameters and the rendering depth parameters, where 
     specifically, the map generating unit  403  includes a calculation unit  4031  and a map generating subunit  4032 , where 
     the calculation unit  4031 , for each ray light source, calculates an AO value of each pixel point in a direction of the ray light source according to a scene depth parameter and a rendering depth parameter of each pixel point of the to-be-rendered target object; and 
     the map generating subunit  4032  that overlays the AO values to obtain an AO map of the to-be-rendered target object in the direction of the ray light source; 
     an output processing unit  404 , that overlays the AO maps in the directions of the ray light sources, to obtain an output image; and 
     a correction unit  405 , that performs a Gamma correction on the output image and output the output image. 
     To further understand the technical solutions of the present disclosure, the following describes a manner in which the units in the image processing apparatus  400  in this embodiment interact with each other, which is specifically as follows: 
     In this embodiment, a model of the to-be-rendered target object is established in the CPU, ray light sources are set, and the CPU shoots the to-be-rendered target object by using a simulated camera located at a ray light source, to obtain the information about the scene within the preset range around the to-be-rendered target object, where the preset range may be preset in the CPU according to an actual need, and the obtained scene may include the to-be-rendered target object and another object, terrain, or the like. The CPU sends the obtained information about the scene within the preset range around the to-be-rendered target object to the image processing apparatus, and the receiving unit  401  receives the information, which is sent by the CPU, about the scene within the preset range around the to-be-rendered target object. The scene received by the receiving unit  401  includes the to-be-rendered target object and another object, terrain, or the like, and the received information about the scene may further include relevant parameters of the camera at the ray light source, for example, a vision matrix, a projection matrix, and a lens position. 
     The rendering processing unit  402  renders the scene received by the receiving unit  401 , to obtain a scene depth image, where the scene depth image stores a scene depth parameter of each pixel point in the scene shot by the camera at the ray light source, that is, also includes a scene depth parameter of each pixel point of the to-be-rendered target object. 
     Next, the rendering processing unit  402  renders the to-be-rendered target object to obtain the rendering depth parameters, where the to-be-rendered target object is obtained through shooting by the camera not located at a ray light source, where the camera may shoot the to-be-rendered target object separately in a parallel projection manner, and a selected shooting angle needs to enable the entire to-be-rendered target object to be shot. 
     Specifically, the rendering processing unit  402  renders the to-be-rendered target object, and obtains a rendering depth image after the rendering, obtains a vertex coordinate of the to-be-rendered target object from the rendering depth image, and multiplies the vertex coordinate of the to-be-rendered target object by a world coordinate matrix, and then by vision matrixes and projection matrixes of cameras located at the ray light sources, to obtain the rendering depth parameters of the to-be-rendered target object. The rendering depth parameters of the to-be-rendered target object include a rendering depth parameter of each pixel point of the to-be-rendered target object. 
     The map generating unit  403  calculates the AO maps of the to-be-rendered target object in the directions of the ray light sources according to the scene depth parameters and the rendering depth parameters obtained by the rendering processing unit  402 . 
     Specifically, for each ray light source, the calculation unit  4031  obtains a scene depth parameter corresponding to the to-be-rendered target object shot by the camera at the ray light source, and the rendering depth parameter of the to-be-rendered target object shot by the camera not located at any ray light source, and calculates the AO value of each pixel point in the direction of the ray light source according to the scene depth parameter and the rendering depth parameter of each pixel point of the to-be-rendered target object, and a calculation process is as follows: 
     For a pixel point, the calculation unit  4031  compares a rendering depth parameter of the pixel point with a scene depth parameter of the pixel point, and determines, when the rendering depth parameter is greater than the scene depth parameter, that a shadow value of the pixel point is 1; and determines, when the rendering depth parameter of the pixel point is less than or equal to the scene depth parameter, that the shadow value of the pixel point is 0. 
     Then, the calculation unit  4031  multiplies the shadow value of the pixel point by a weight coefficient to obtain the AO value of the pixel point in the direction of the ray light source, where the weight coefficient includes a dot product of an illumination direction of the ray light source and a normal direction of the pixel point, and a reciprocal of a total number of the ray light sources, for example, when the number of the ray light sources is 900, the reciprocal of the total number of the ray light sources is 1/900. 
     In addition, to ensure calculation accuracy for the AO value of each the pixel point, the calculation unit  4031  may further multiply the foregoing AO value obtained through calculation by a preset experience coefficient, where the experience coefficient is measured according to an experiment, and may be 0.15. 
     The map generating subunit  4032  overlays the AO value of each pixel point calculated by the calculation unit  4031  to obtain the AO value of the to-be-rendered target object, and draws the AO map of the to-be-rendered target object in the direction of the ray light source according to the AO value of the to-be-rendered target object. By analogy, the map generating subunit  4032  may obtain an AO map of the to-be-rendered target object in a direction of each ray light source according to the foregoing method. 
     The output processing unit  404  overlays the AO maps in the directions of the ray light sources, which are generated by the map generating subunit  4032 , to obtain the output image. 
     A black border may be generated on the output image due to sawteeth and texture pixel overflowing. The output processing unit  404  may process the black border generated due to the sawteeth by using “percentage progressive filtration” of a shadow, and for each pixel, average pixels above, below, to the left of, and to the right of this pixel, and this pixel itself. The output processing unit  404  may solve the black border generated due to the pixel overflowing by expanding effective pixels. Specifically, whether a current pixel is ineffective may be determined in a pixel shader. If the current pixel is ineffective, 8 surrounding pixels are sampled, and effective pixels thereof are added up, an average value of the effective pixels is obtained, the average value is used as a shadow value of the current pixel, and the current pixel is set to be effective. In this way, expansion of one pixel for the output image to prevent sampling from crossing a boundary is implemented. 
     Finally, the correction unit  405  performs the Gamma correction on the output image of the output processing unit  404 , that is, the correction unit  405  pastes the output image onto the model of the to-be-rendered target object for displaying, and adjusts a display effect of the output image by using a color chart, to solve a problem that a scene dims as a whole because AO is added to the scene. For a specific correction effect, refer to  FIG. 6  and  FIG. 7 , where  FIG. 6  shows a display effect of the output image on which the Gamma correction is performed, and  FIG. 7  shows a display effect of the output image on which the Gamma correction is performed. 
     In this embodiment, the map generating unit can calculate AO maps of a to-be-rendered target object in directions of ray light sources only according to scene depth parameters and rendering depth parameters, and the output processing unit can obtain an output image by simply overlaying the AO maps in the directions of the ray light sources, which avoids a complex calculation process in the prior art; and an image data processing capability that the image processing apparatus in this embodiment has is more powerful than an image data processing capability of a CPU, which improves image processing efficiency. It is measured through an experiment that, it takes only several minutes to generate one AO map by using the image processing apparatus provided by this embodiment, and the used time is far shorter than the time for generating an AO map in the prior art. 
     The following describes a computer device provided by an embodiment of the present invention. Referring to  FIG. 5 , the computer device  500  may include components such as a Radio Frequency (RF) circuit  510 , a memory  520  that includes one or more computer readable storage mediums, an input unit  530 , a display unit  540 , a sensor  550 , an audio circuit  560 , a Wi-Fi module  570  (e.g., WiFi module, wireless fidelity module), a processor  580  that includes one or more processing cores, and a power supply  590 . 
     A person skilled in the art can understand that, the structure of the computer device shown in  FIG. 5  does not constitute a limit to the computer device, and may include components that are more or fewer than those shown in the figure, or a combination of some components, or different component arrangements. 
     The RF circuit  510  may receive and send a message, or receive and send a signal during a call, and particularly, after receiving downlink information of a base station, submit the information to one or more processors  580  for processing; and in addition, send involved uplink data to the base station. Generally, the RF circuit  510  includes but is not limited to an antenna, at least one amplifier, a tuner, one or more oscillators, a subscriber identity module (SIM) card, a transceiver, a coupler, a low noise amplifier (LNA), and a duplexer. In addition, the RF circuit  510  may further communicate with another device through wireless communication and a network; and the wireless communication may use any communications standard or protocol, including but not limited to Global System of Mobile communication (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), e-mail, and Short Messaging Service (SMS). 
     The memory  520  may store a software program and a module, and the processor  580  executes various functional applications and data processing by running the software program and module that are stored in the memory  520 . The memory  520  may mainly include a program storage area and a data storage area, where, the program storage area may store an operating system, an application program required by at least one function (for example, a voice playback function and an image playback function), and the like; the data storage area may store data (for example, audio data and a telephone directory) created according to use of the computer device  500 , and the like; in addition, the memory  520  may include a high speed random access memory (RAM), and may further include a non-volatile memory, for example, at least one magnetic disk storage device, a flash memory, or another volatile solid-state memory. Accordingly, the memory  520  may further include a memory controller, so that the processor  580  and the input unit  530  access the memory  520 . 
     The input unit  530  may receive input digit or character information, and generate keyboard, mouse, joystick, optical, or track ball signal input related to user setting and function control. Specifically, the input unit  530  may include a touch-sensitive surface  531  and another input device  532 . The touch-sensitive surface  531  may also be referred to as a touch screen or a touch panel, and may collect a touch operation of a user on or near the touch-sensitive surface  531  (such as, an operation of a user on or near the touch-sensitive surface  531  by using any suitable object or attachment, such as a finger or a touch pen), and drive a corresponding connection apparatus according to a preset program. Optionally, the touch-sensitive surface  531  may include two parts: a touch detection apparatus and a touch controller. The touch detection apparatus detects a touch position of the user, detects a signal brought by the touch operation, and transfers the signal to the touch controller. The touch controller receives touch information from the touch detection apparatus, converts the touch information to touch point coordinates, and sends the touch point coordinates to the processor  580 . Moreover, the touch controller can receive and execute a command sent from the processor  580 . In addition, the touch-sensitive surface  531  may be implemented by using various types such as a resistive type, a capacitive type, an infrared type, and a surface sound wave type. In addition to the touch-sensitive surface  531 , the input unit  530  may further include the another input device  532 . Specifically, the another input device  532  may include, but is not limited to, one or more of a physical keyboard, a function key (such as a volume control key or a switch key), a track ball, a mouse, and a joystick. 
     The display unit  540  may display information input by the user or information provided for the user, and various graphical user interfaces of the computer device  500 . The graphical user interfaces may be formed by a graph, a text, an icon, a video, and any combination thereof. The display unit  540  may include a display panel  541 . Optionally, the display panel  541  may be configured by using a liquid crystal display (LCD), an organic light-emitting diode (OLED), or the like. Further, the touch-sensitive surface  531  may cover the display panel  541 . After detecting a touch operation on or near the touch-sensitive surface  531 , the touch-sensitive surface  531  transfers the touch operation to the processor  580 , so as to determine a type of a touch event. Then, the processor  580  provides corresponding visual output on the display panel  541  according to the type of the touch event. Although, in  FIG. 5 , the touch-sensitive surface  531  and the display panel  541  are used as two separate parts to implement input and output functions, in some embodiments, the touch-sensitive surface  531  and the display panel  541  may be integrated to implement the input and output functions. 
     The computer device  500  may further include at least one sensor  550 , such as an optical sensor, a motion sensor, and other sensors. Specifically, the light sensor may include an ambient light sensor and a proximity sensor. The ambient light sensor may adjust luminance of the display panel  541  according to brightness of ambient light. The proximity sensor may switch off the display panel  541  and/or backlight when the computer device  500  is moved to the ear. As one type of motion sensor, a gravity acceleration sensor may detect magnitude of accelerations in various directions (which are generally triaxial), may detect magnitude and a direction of the gravity when static, and may identify an application of a computer device posture (such as switchover between horizontal and vertical screens, a related game, and gesture calibration of a magnetometer), a related function of vibration identification (such as a pedometer and a knock). Other sensors, such as a gyroscope, a barometer, a hygrometer, a thermometer, and an infrared sensor, which may be further configured in the computer device  500 , are not further described herein. 
     The audio circuit  560 , a loudspeaker  561 , and a microphone  562  may provide audio interfaces between the user and the computer device  500 . The audio circuit  560  may transmit, to the loudspeaker  561 , a received electrical signal converted from audio data. The loudspeaker  561  converts the electrical signal into a voice signal for output. On the other hand, the microphone  562  converts a collected sound signal into an electrical signal. The audio circuit  560  receives the electrical signal and converts the electrical signal into audio data, and outputs the audio data to the processor  580  for processing. Then, the processor  580  sends the audio data to, for example, another terminal by using the RF circuit  510 , or outputs the audio data to the memory  520  for further processing. The audio circuit  560  may further include an earplug jack, so as to provide communication between a peripheral earphone and the computer device  500 . 
     WiFi belongs to a short distance wireless transmission technology. The computer device  500  may help, by using the WiFi module  570 , a user receive and send an email, browse a Web page, and access stream media, and the like, which provides wireless broadband Internet access for the user. Although  FIG. 5  shows the WiFi module  570 , it may be understood that, the WiFi module  570  does not belong to a necessary constitution of the computer device  500 , and can be ignored completely according to demands without changing the scope of the essence of the present disclosure. 
     The processor  580  is a control center of the computer device  500 , and connects various parts of the computer device by using various interfaces and lines. By running or executing the software program and/or module stored in the memory  520 , and invoking the data stored in the memory  520 , the processor  580  performs various functions and data processing of the computer device  500 , thereby performing overall monitoring on the computer device. Optionally, the processor  580  may include one or more processing cores. Preferably, the processor  580  may integrate an application processor and a modem. The application processor mainly processes an operating system, a user interface, an application program, and the like. The modem mainly processes wireless communication. It may be understood that, the foregoing modem may be not integrated into the processor  580 . 
     The computer device  500  further includes the power supply  590  (such as a battery) for supplying power to the components. Preferably, the power supply may be logically connected to the processor  580  by using a power supply management system, thereby implementing functions, such as charging, discharging, and power consumption management, by using the power supply management system. The power supply  590  may further include any component, such as one or more direct current or alternating current power supplies, a recharging system, a power supply fault detection circuit, a power supply converter or an inverter, and a power supply state indicator. 
     Although not shown in the figure, the computer device  500  may further include a camera, a Bluetooth module, and the like, which are not further described herein. 
     Specifically, in some embodiments of the present invention, the processor  580  includes a CPU  581  and a GPU  582 , and the computer device further includes a memory and one or more programs. The one or more programs are stored in the memory, and are configured to be executed by the CPU  581 . The one or more programs include instructions for performing the following operations: determining ray points that use a to-be-rendered target object as a center and are distributed in a spherical shape or a semispherical shape; and establishing, at a position of each ray point, a ray light source that radiates light towards the to-be-rendered target object. 
     In addition, the one or more programs that are configured to be executed by the GPU  582  include instructions for performing the following operations: receiving information, which is sent by the CPU  581 , about a scene within a preset range around a to-be-rendered target object; rendering the received scene to obtain scene depth parameters, where the scene is obtained through shooting by a camera located at a ray light source; rendering the to-be-rendered target object to obtain rendering depth parameters, where the to-be-rendered target object is obtained through shooting by a camera not located at a ray light source; calculating AO maps of the to-be-rendered target object in directions of ray light sources according to the scene depth parameters and the rendering depth parameters; and overlaying the AO maps in the directions of the ray light sources, to obtain an output image. 
     It is assumed that, the foregoing is a first possible implementation manner, and then in a second possible implementation manner provided based on the first possible implementation manner, the one or more programs executed by the GPU  582  further include instructions for performing the following operations: for each ray light source, calculating an AO value of each pixel point in a direction of the ray light source according to a scene depth parameter and a rendering depth parameter of each pixel point of the to-be-rendered target object; and overlaying the AO values to obtain an AO map of the to-be-rendered target object in the direction of the ray light source. 
     In a third possible implementation manner provided based on the second possible implementation manner, the one or more programs executed by the GPU  582  further include instructions for performing the following operations: calculating, according to the scene depth parameter and the rendering depth parameter of each pixel point, a shadow value of the pixel point; and multiplying the shadow value of the pixel point by a weight coefficient, to obtain the AO value of the pixel point in the direction of the ray light source, where the weight coefficient includes a dot product of an illumination direction of the ray light source and a normal direction of the pixel point, and a reciprocal of a total number of the ray light sources. 
     In a fourth possible implementation manner provided based on the third possible implementation manner, the one or more programs executed by the GPU  582  further include instructions for performing the following operations: determining, when the rendering depth parameter of the pixel point is greater than the scene depth parameter, that the shadow value of the pixel point is 1; and determining, when the rendering depth parameter of the pixel point is less than or equal to the scene depth parameter, that the shadow value of the pixel point is 0. 
     In a fifth possible implementation manner provided based on the first, or second, or third, or fourth possible implementation manner, the one or more programs executed by the GPU  582  further include instructions for performing the following operations: rendering the to-be-rendered target object to obtain a vertex coordinate of the to-be-rendered target object; and multiplying the vertex coordinate by a world coordinate matrix, and then by vision matrixes and projection matrixes of cameras located at the ray light sources, to obtain the rendering depth parameters. 
     In a sixth possible implementation manner provided based on the first, or second, or third, or fourth possible implementation manner, the one or more programs executed by the GPU  582  further include an instruction for performing the following operation: performing a Gamma correction on the output image and outputting the output image. 
     In this embodiment, a GPU can calculate AO maps of a to-be-rendered target object in directions of ray light sources only according to scene depth parameters and rendering depth parameters, and can obtain an output image by simply overlaying the AO maps in the directions of the ray light sources, which avoids a complex calculation process in the prior art; and these image calculation and processing processes are completed by the GPU, and a powerful capability of the GPU for processing image data is utilized, which therefore saves an image processing time, and improves image processing efficiency. 
     It should be additionally noted that, the apparatus embodiments described above are only schematic. Units described as separate components may be or may not be physically separate, and parts displayed as units may be or may not be physical units, may be located in one position, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments. In addition, in the accompanying drawings of the apparatus embodiments provided by the present disclosure, a connection relationship between the units indicates that there is a communication connection between them, and may be specifically implemented as one or more communications buses or signal lines. A person of ordinary skill in the art can understand and carry out the solution without creative efforts. 
     Through the descriptions of the foregoing embodiments, a person skilled in the art may clearly understand that the present disclosure may be implemented by software plus necessary universal hardware, and certainly may also be implemented by specific hardware including a specific integrated circuit, a specific CPU, a specific memory, and a specific component. In a normal case, all functions completed by a computer program can be easily implemented by using corresponding hardware, and specific hardware structures for implementing a same function may also be varied, for example, an analog circuit, a digital circuit, or a specific circuit. However, for the present disclosure, in more cases, an implementation by using a software program is a better implementation manner. Based on such an understanding, the technical solutions of the present disclosure essentially or the part contributing to the prior art may be implemented in a form of a software product. The computer software product is stored in a readable storage medium, such as a floppy disk, a USB disk, a removable hard disk, a read-only memory (ROM), a RAM, a magnetic disk, an optical disc, or the like in a computer, and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) to perform the methods described in the embodiments of the present invention. 
     The image processing method and apparatus, and the computer device that are provided by the embodiments of the present invention are described in detail above. For a person of ordinary skill in the art, modifications may be made to specific implementation manners and the application scope according to the idea of the embodiments of the present invention. Therefore, the content of the specification shall not be construed as a limit to the present disclosure.