JP2015125509A - Image processing apparatus, image processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of data to be transferred, and to reduce object drawing time.SOLUTION: An image processing apparatus for drawing an image based on a drawing instruction so as to overwrite a drawn image includes: a receiving section which receives a frame drawing instruction; an extraction section which analyzes the drawing instruction to extract a partial area to be updated, in the drawn image; a management section which manages an area to be obtained by the sum of the partial area and a partial area extracted by analyzing a drawing instruction prior to receiving the drawing instruction, as an update area; a storage section having a drawing buffer for holding the drawn image; and a drawing section which reads the drawn image in an area corresponding to the update area from the drawing buffer, and draws an image based on the drawing instruction and an image based on the drawing instruction received prior to the drawing instruction so as to overwrite the read image.

Description

  The present invention relates to an image processing technique for drawing a vector graphics animation.

  Systems that use vector graphics for drawing animation have become widespread. With the increase in screen size and resolution of display devices, the number of pixels handled by the renderer used to draw an image is expected to increase in the future. When the number of pixels to be drawn is large, vector graphics that specify the shape of a drawing figure (object) using coordinate information and color information have more data to use for drawing instructions than raster graphics that use a bitmap. small.

  A renderer that draws vector graphics animation draws each frame constituting the animation in turn. In addition to the method of redrawing all the elements included in the update target area of the animation, there is a method of drawing the difference updated in the current frame in the previously drawn image. Japanese Patent Application Laid-Open No. 2004-228561 discloses a configuration that reduces the drawing load by not drawing other parts of a drawing area that is not updated when only a part of a certain drawing area is updated.

JP 2004-354896 A

  As the number of drawing pixels increases, the amount of image data that the renderer refers to at the time of drawing and the amount of data transfer required to output the drawn data has increased. In a system using a double buffer or a multi-buffer, data transfer for copying a drawn image or a background image also occurs.

  Even if it is a method of redrawing all objects included in the area to be updated, if the object to be redrawn is a filter process or a bitmap image overlay, it is necessary to repeat access to the image data every frame. is there. When such object redrawing occurs, the data transfer amount for redrawing increases. In addition, redrawing of an object with a heavy processing load may cause performance degradation.

  In view of the above problems, an object of the present invention is to provide an image processing technique capable of reducing the amount of data transfer and shortening the drawing time of an object.

An image processing apparatus according to one aspect of the present invention is an image processing apparatus that draws an image based on a drawing command over an already drawn image,
Receiving means for receiving a frame drawing command;
Extracting means for analyzing the drawing command and extracting a partial area to be updated out of the area in the drawn image;
A management means for managing an area acquired by taking the sum of the partial area and a partial area extracted by analysis of the drawing command received before receiving the drawing command as an update area;
Storage means having a drawing buffer for holding a drawn image;
Read the drawn image of the area corresponding to the update area from the drawing buffer, and convert the image based on the drawing command and the image based on the drawing command received before receiving the drawing command to the read image. And a drawing means for overwriting.

  According to the present invention, an object of the present invention is to provide an image processing technique capable of reducing the data transfer amount and shortening the drawing time of an object. Even when drawing to a plurality of buffers, it is not necessary to make a full copy of the drawn image, and the data transfer amount can be reduced. Further, when a drawn image includes a large number of objects and image processing, the drawing time can be shortened as compared with a method of redrawing all objects.

1 is a block diagram showing a functional configuration of an image processing apparatus according to an embodiment. FIG. 6 is a diagram for explaining the operation of the image processing apparatus according to the embodiment. The figure explaining the process of a drawing part. The figure explaining the process of a data holding part.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the components described in this embodiment are merely examples, and the technical scope of the present invention is determined by the scope of the claims, and is not limited by the following individual embodiments. Absent.

  FIG. 1 is a block diagram showing a functional configuration of the image processing apparatus according to the present embodiment.

  The image processing apparatus overwrites and draws an image based on the drawing command on the drawn image. In FIG. 1, an image input unit 101 receives a vector graphics drawing command (hereinafter also simply referred to as a drawing command). The update area extraction unit 102 analyzes the drawing command and extracts a partial area to be updated from the areas in the drawn image. The update area extraction unit 102 extracts, from the drawing command, an area for updating the area drawn by the drawing command for the current frame (partial update target area) as a partial update area. The update information management unit 103 manages a region (partial update region) that is a target of partial update extracted by the update region extraction unit 102. The update information management unit 103 manages, as an update area, an area acquired by taking the sum of the partial area and the partial area extracted by the analysis of the drawing command before receiving the drawing command.

  The drawing unit 104 performs drawing processing based on the drawing command. The drawing unit 104 reads a drawn image in an area corresponding to the update area from the drawing buffer, and draws an image based on the drawing command over the read image.

  The data holding unit 105 holds a group of object information necessary for redrawing an object defined by a drawing command from one frame before to n−1 frames before as object information acquired by analyzing the drawing command. The drawing unit 104 obtains object information from the data holding unit 105, adds an image based on the drawing command received by the image input unit 101, and object information to a drawn image in an area corresponding to the update area read from the drawing buffer. Overwrite the image based on it.

  The output control unit 106 outputs the drawing result of the drawing unit 104 to the drawing buffer of the data storage unit 107. The output control unit 106 writes the image overwritten by the drawing unit 104 back to the drawing buffer as a drawing result. The data storage unit 107 has a plurality of drawing buffers for storing the drawing results of the drawing unit 104 (n-plane, where n is a natural number of 2 or more).

  In the present embodiment, as an example, a description will be given of a configuration in which the number n of drawing buffers held by the data storage unit 107 is 2, and the drawing buffer of two sides is switched for each frame and used as an output buffer. Note that the gist of the present invention is not limited to the case where the number of planes n of the drawing buffer is 2, but it may be 2 or more. For example, the number n of drawing buffer surfaces may be three or more according to system requirements. When the number n of faces of the drawing buffer is 2, the redraw target frame is only the frame one frame before the frame being drawn. For example, when the number n of drawing buffer planes is 3, the frames to be redrawn are two frames, one frame before and two frames before counting from the frame being drawn.

  The operation of the image processing apparatus configured as described above will be described with reference to FIGS. First, main operations of the image processing apparatus will be described with reference to FIG. In step 201, the drawing unit 104 initializes an object information group to be referred to at the time of drawing. Next, in step 202, the update region extraction unit 102 analyzes the drawing command and extracts the coordinates, shape, color, and hierarchical relationship with other objects from the drawing command as object information.

  In step 203, the update area extraction unit 102 determines whether there is an area to be updated based on the object information extracted in step 202. The update area extraction unit 102 determines whether each object of the drawing command contributes to the final drawing result. For example, drawing outside the area of the drawing buffer or drawing with a transparent color does not appear in the final drawing result, and thus a drawing command for such a drawing area of the object is excluded from the target of subsequent processing in step 203. In this case, assuming that there is no area to be updated, the process proceeds to step 205. On the other hand, if it is determined in step 203 that the object of the drawing command appears in the final drawing result based on the object information and contributes to the final drawing result, the processing is performed assuming that there is an area to be updated. Proceed to 204.

  In step 204, the update information management unit 103 adds and registers the extracted object to the list as a partial update area of the frame being drawn.

  In step 205, the update region extraction unit 102 analyzes the drawing command and determines whether or not the drawing command notifies the completion of processing of one frame. If the processing for one frame is not completed, the process returns to step 202 and the processes from step 202 to step 204 are repeated. On the other hand, if it is determined in step 205 that the drawing command for one frame is completed, the update information management unit 103 completes the update of the partial update area list and proceeds to step 206.

  In step 206, the update information management unit 103 refers to the list of partial update areas generated in step 204 and the list of partial update areas generated one frame before the update target frame. And the update information management part 103 acquires the area | region (sum area | region) acquired by taking the sum of the object of the partial update area | region contained in a list | wrist as an update area | region. The update information management unit 103 holds the list of partial update areas obtained for each frame by the same number of frames as the number of drawing buffer planes (for example, two drawing buffer planes are two frames).

  As another implementation method for holding the partial update area list, for example, the object information group held by the data holding unit 105 may include the partial update area list. Alternatively, the drawing unit 104 may generate a list of partial update areas for each frame using coordinate information and color information included in the object information group, and pass the list to the update information management unit 103. The partial update area generated in step 204 may use a bounding box of a rectangular area including all areas (partial areas) that can be updated by the object without using the exact shape of the object drawn by each drawing command.

  Since the configuration of the present embodiment is a double buffer having two drawing buffer planes, the drawn image of the previous two frames remains in the drawing buffer except for the two frames after the start of drawing. In step 207, the drawing unit 104 reads a drawn image of a portion corresponding to the area defined by the update area from the drawing buffer. The drawing unit 104 uses the read drawn image as a background, and sequentially overwrites the object information group held by the data holding unit 105 and the object designated by the drawing command. Specific operation contents of the drawing unit 104 will be described later with reference to FIG. When the drawing unit 104 overwrites the object information group and the object specified by the drawing command with the drawn image as the background, the output control unit 106 writes back to the read drawing buffer. When the writing back to the drawing buffer is completed, the drawing unit 104 switches the buffer for reading the drawn image to the next drawing buffer.

  An object drawn by a drawing command two or more frames ago does not need to be redrawn by the drawing unit 104 because the drawing unit 104 reads the background as a drawn image from the drawing buffer. Therefore, in step 208, the output control unit 106 deletes the object information group two frames before remaining in the data holding unit 105 by a method described later. In step 209, the drawing unit 104 determines whether to continue drawing. If drawing of the next frame continues, the process returns to step 202, and the same process is continued after step 202.

  Generally, when drawing is performed by sequentially switching the drawing buffer for n planes, an object drawn by a drawing command for n frames before remains in the drawing buffer. An object remaining in the drawing buffer can be replaced with redrawing by reading it as a background. Therefore, the data holding unit 105 deletes the object information group n frames before when switching the drawing buffer.

  Next, the operation of the drawing unit 104 in step 207 will be described with reference to FIG. FIG. 3 shows a method of deleting the object information group n frames before by a method of clipping at the clip level inserted by the drawing unit 104. As another configuration, an object drawn in the nth frame (frame n) (n is a natural number) from the object information group may be searched and deleted.

  In the rendering command of vector graphics, the deformation instruction matrix of the drawing object, the color and style of the object, etc. are not always explicitly specified when drawing each object, but the settings held by the drawing unit 104 when the drawing command is executed May refer to parameters. The setting parameter is set to an initial value when the drawing unit 104 is initialized, and thereafter, the drawing unit 104 holds the setting changed by the drawing command. For this reason, the drawing unit 104 needs to restore the setting parameters of the drawing unit 104 at the start of drawing of the n−1 frame prior to drawing when redrawing the object of n−1 frame before. In step 301, the drawing unit 104 acquires the setting parameters of the drawing unit 104 for the previous n−1 frames from the object information group held by the data holding unit 105.

  In step 302, the drawing unit 104 sequentially outputs and stores the object information defined by the drawing command received by the image input unit 101 to the data holding unit 105. In this embodiment, the object information group of the update target frame stored in the data holding unit 105 includes a combination of a drawing command for each frame and a setting parameter at the start of drawing for each frame. Another example of the configuration of the object information group includes one in which the drawing unit 104 interprets a drawing command for each frame and converts it into an intermediate data format having object shape, hierarchy, and color information.

  In step 303, if the drawing command for one frame is not completed, the drawing unit 104 returns the process to step 302 and repeats the same process. On the other hand, if it is determined in step 303 that all drawing commands have been processed, the drawing unit 104 advances the process to step 304.

  In step 304, the drawing unit 104 adds a clip-level drawing command for the current frame m (m is a natural number) to the end of the one-frame command received by the image input unit 101. Identification information (ID) that can identify any drawing buffer is assigned to the clip level from the drawing buffer of the n plane. In the case of a double buffer, the identification information (ID) may be a 1-bit flag that identifies two buffers.

  In step 305, the drawing unit 104 performs object drawing processing. The drawing unit 104 uses the drawn image in the update area read from the drawing buffer as a background, and overwrites and draws the object one frame before the data holding unit 105 and the object designated by the drawing command in order. When there are three drawing buffers, a 2-bit value is prepared as identification information (ID), and objects designated by the drawing command are overwritten in order after two frames.

  In step 306, the drawing unit 104 ends the process when the clip level of the mn frame does not exist. The drawing unit 104 notifies the data holding unit 105 and the update information management unit 103 of the completion of drawing.

  On the other hand, if it is determined in step 306 that there is an mn frame clip level, the rendering unit 104 advances the process to step 307. In step 307, the drawing unit 104 deletes the object information below the clip level mn, and ends the process.

  The drawing unit 104 outputs the setting parameters of the drawing unit 104 at the completion of drawing to the data holding unit 105. The drawing unit 104 switches the drawing buffer to the next drawing buffer, and the drawing unit 104 completes drawing of one frame.

  Next, an object information group update process performed by the data holding unit 105 will be described with reference to FIG. In step 401, the data holding unit 105 acquires the setting parameter output from the drawing unit 104 when the m−1th frame (previous frame) is drawn as the setting parameter of the next frame m. In the subsequent steps, the data holding unit 105 associates this setting parameter with the object information input for the frame m and records it as an object information group.

  In step 402, the data holding unit 105 acquires the object information of the current frame m, and records the setting parameters acquired in step 401 in association with each other. In step 403, the data holding unit 105 waits for a drawing completion notification to be output from the drawing unit 104.

  In step 404, the data holding unit 105 searches for a clip level having an ID of n frames before from the object information group held by the data holding unit 105. If a clip level having an ID of n frames before exists in the object information group, the data holding unit 105 advances the process to step 405. In step 405, the data holding unit 105 deletes the clip level having the ID of n frames before and the drawing command before n frames input to the data holding unit 105 before the drawing command of the same clip level. In step 406, the setting parameter before n frames associated with the drawing command before n frames is also deleted.

  If it is determined in step S404 that there is no clip level having an ID of n frames before in the data holding unit 105, there is no data usable as a background in the drawing buffer. For this reason, the data holding unit 105 ends the process without performing the deletion process of the object information group.

  The amount of data transfer can be reduced, and the object drawing time can be shortened. Even for drawing using a plurality of buffers, it is not necessary to copy the entire drawn image, and the amount of data transfer can be reduced. Further, when a drawn image includes a large number of objects and image processing, the drawing time can be shortened as compared with a method of redrawing all objects.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (11)

An image processing apparatus for overwriting an image based on a drawing command on a drawn image,
Receiving means for receiving a frame drawing command;
Extracting means for analyzing the drawing command and extracting a partial area to be updated out of the area in the drawn image;
A management means for managing an area acquired by taking the sum of the partial area and a partial area extracted by analysis of the drawing command received before receiving the drawing command as an update area;
Storage means having a drawing buffer for holding a drawn image;
Read the drawn image of the area corresponding to the update area from the drawing buffer, and convert the image based on the drawing command and the image based on the drawing command received before receiving the drawing command to the read image. A drawing means for overwriting,
An image processing apparatus comprising: Output control means for writing the drawing result of the drawing means into the drawing buffer;
The image processing apparatus according to claim 1, wherein the output control unit writes the overwritten image back into the drawing buffer as a drawing result.   The image processing apparatus according to claim 1, wherein the storage unit includes a plurality of drawing buffers that hold a drawn image for each frame. Further comprising data holding means for holding object information acquired by analysis of the drawing command;
The drawing means includes
Obtaining object information obtained by analyzing the drawing command prior to receiving the drawing command from the data holding means;
The image processing apparatus according to claim 1, wherein the image based on the object information is overwritten and rendered as an image based on a drawing command received before the drawing command is received. The management means has a list for registering the partial area extracted by the extraction means for each frame,
The image processing apparatus according to claim 1, wherein the management unit manages an area acquired by taking the sum of the partial areas included in the list with reference to the list as an update area.   The image processing apparatus according to claim 5, wherein the update area is a bounding box of a rectangular area including the partial area.   The image processing apparatus according to claim 1, wherein the image read from the drawing buffer is a drawn image indicating a background. The extraction means analyzes the drawing command, extracts the coordinates at which the object is drawn, the shape of the object, the color of the object, and the hierarchical relationship with other objects from the drawing command as object information,
The image processing apparatus according to claim 1, wherein the extraction unit removes, from the partial area to be updated, a drawing area of an object that does not appear in a drawing result based on the extraction result. . An image of an image processing apparatus that has a receiving unit that receives a drawing command for a frame and a storage unit that has a drawing buffer that holds a drawn image, and that overwrites the drawn image with an image based on the drawing command A processing method,
An extraction step in which the extraction means of the image processing apparatus analyzes the drawing command and extracts a partial area to be updated out of the area in the drawn image;
The management means of the image processing apparatus manages, as an update area, an area acquired by summing the partial area and the partial area extracted by analyzing the drawing command before receiving the drawing command. A management process to
The drawing unit of the image processing apparatus reads a drawn image of the area corresponding to the update area from the drawing buffer, and based on the drawing command received before receiving the image based on the drawing command and the drawing command A drawing process of overwriting the image with the read image;
An image processing method comprising: The output control means of the image processing apparatus further includes an output control step of writing the drawing result of the drawing step into the drawing buffer;
The image processing method according to claim 9, wherein the output control step writes the overdrawn image back to the drawing buffer as a drawing result.   The program for functioning a computer as each means of the image processing apparatus of any one of Claims 1 thru | or 8.

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