JP2015075839A - Image processing apparatus, image processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus configured to execute composite processing between groups at a high speed, to increase overall printing speed.SOLUTION: An image processing apparatus includes: means for interpreting a display list to load an object; means for determining whether the loaded object is non-transmissive and is located higher in order than an object already acquired; means for holding a group number of a group to which the loaded object belongs and coordinates of left and right edges of the object in a current scan line when the loaded object is non-transmissive and is located higher in order than the object already acquired; and means for skipping composite processing in a section indicated by the coordinates of the left and right edges when the composite processing is executed between groups which are lower in order than a group to which the current uppermost object belongs.

Description

  The present invention relates to an image processing device, an image processing method, and a program. Specifically, the present invention relates to an image processing device, an image processing method, and a program that execute pixel composite processing in rendering.

  There is a method called scan line rendering in which print data is read for each line in the main scanning direction and rendered (see Patent Document 1). In scanline rendering, rendering is performed according to information (edge data) about an image object (hereinafter referred to as an “object”) to be drawn in a page and a boundary between the object or an edge indicating a boundary between the object and the background image. Patent Document 1 discloses loading edge data for one line into a memory in order to perform scan line rendering.

  The print data to be rendered created by the user using the application software has become complicated due to an increase in the number of edges included as the rendering performance of the application software increases. For this reason, there are problems such as a shortage of memory resources in the rendering system and a long time for rendering processing.

  As a rendering processing method for print data including a large amount of edges, Japanese Patent Application Laid-Open No. H10-228707 discloses a fallback method in which objects included in page description language (PDL) data to be processed are grouped for each level to generate a plurality of display lists. Disclosed process is called.

JP 2000-137825 A JP 2002-169668 A

  When print data including a large amount of edges is rendered by the scanline rendering process disclosed in Patent Document 1, a fallback process disclosed by Patent Document 2 is executed to generate a display list using limited memory resources. Is possible.

  However, in this method, when the generated display list includes edges that cannot be stored in the CPU cache, it causes frequent occurrence of cache misses in the CPU cache, which takes time for rendering processing, particularly edge processing. There is.

  The present invention is an image processing apparatus that generates a bitmap for a display list and executes a rendering process. The image processing apparatus interprets the display list and loads an object, and the loaded object is opaque and currently grasped. A determination means for determining whether or not the loaded object is higher than the current object, and the group number of the group to which the loaded object belongs and the current process when the loaded object is opaque and higher than the currently known object The holding means that holds the coordinates of the left and right edges of the object in the middle scan line, and the composite process is a composite process between groups, and is executed between groups lower than the group to which the highest-level object currently grasped belongs When to , Characterized in that a skip means for skipping composite processed within a section indicated by the left and right edge coordinates.

  According to the present invention, even when complex data having a large number of edges is subjected to rendering processing, edge processing can be performed at high speed by processing edges for each group. Further, according to the present invention, it is possible to perform composite processing between groups at high speed, and it is possible to perform total printing processing at high speed.

1 is a block diagram illustrating a configuration of an image processing system according to Embodiment 1. FIG. 1 is a block diagram illustrating a configuration of an MFP according to a first embodiment. FIG. 6 is a diagram illustrating scan line rendering processing according to the first embodiment. It is a figure which shows the edge process when the mass edge which concerns on Example 1 is contained in the display list. FIG. 10 is a diagram illustrating edge group division processing according to the first embodiment. It is a figure which shows the composite process in the group which concerns on Example 1, and the composite process between groups. It is a figure which shows the composite skip process between the groups which concern on Example 1. FIG. 7 is a flowchart illustrating composite skip processing between groups according to the first embodiment. It is a figure which shows the composite skip process between the groups in the some area which concerns on Example 2. FIG. 12 is a flowchart illustrating composite skip processing between groups in a plurality of sections according to the second embodiment. It is a figure which shows the composite skip process between groups with selection of the optimal object based on Example 3. FIG. 12 is a flowchart illustrating a composite skip process between groups with selection of an optimal object according to the third embodiment. It is a figure which shows the composite skip process between the groups in the span of objects other than the rectangle which concerns on Example 4. FIG. 14 is a flowchart of composite skip processing between groups in a span of an object other than a rectangle according to the fourth embodiment. It is a figure which shows the simple composite skip process between groups in the span of the objects other than the rectangle which concerns on Example 5. FIG. 16 is a flowchart of a simple composite skip process between groups in a span of an object other than a rectangle according to the fifth embodiment. It is a flowchart which shows the relationship between the edge group division | segmentation process based on this invention, and a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<System configuration>
FIG. 1 is a block diagram illustrating the configuration of the image processing system according to the first embodiment. In this system, one host computer (hereinafter referred to as “PC”) 130 and two image processing apparatuses 100 and 110 are connected to a LAN 140. However, in the image processing system according to the present invention, the number of connections of the host computer and the image processing apparatus is not limited to these. In this embodiment, the LAN is applied as the connection means, but the connection means is not limited to this. For example, an arbitrary network such as a WAN (public line), a serial transmission method such as USB, or a parallel transmission method such as Centronics or SCSI can be applied.

  The PC 130 has a function of a personal computer. The PC 130 can send and receive files and send and receive e-mails using the FTP and SMB protocols via the LAN 140 and WAN. Further, the PC 130 can issue a print command to the image processing apparatuses 100 and 110 via a printer driver.

  The image processing apparatus 100 and the image processing apparatus 110 have the same configuration, and both are image processing apparatuses having a scanner unit. For the sake of simplicity, the configuration will be described in detail below with a focus on the image processing apparatus 110 of the image processing apparatuses 100 and 110.

  The image processing apparatus 110 includes a scanner unit 113 that is an image input device, a printer unit 114 that is an image output device, a controller 111 that controls operation of the entire image processing apparatus 110, and an operation unit 112 that is a user interface (UI). It consists of.

<Configuration of controller unit>
FIG. 2 is a block diagram illustrating a configuration of a control unit (controller) of an MFP (Multifunction Peripheral) according to the first embodiment. FIG. 2 is a diagram showing a detailed configuration of the controller 101 and the controller 111 in FIG. The control unit 200 is connected to a scanner unit 201 that is an image input device and a printer unit 202 that is an image output device, and performs control for reading image data and printing output. The control unit 200 is connected to the LAN N1 and the public line 204, and performs control for inputting and outputting image information and device information via the LAN N1 and the public line 204. The printer unit 202 is connected to the device I / F 217, and the printer engine included in the printer unit 202 performs a process of outputting the drawing data generated by the control unit 200 to paper.

  A CPU 205 is a central processing unit for controlling the entire MFP. A RAM 206 is a system work memory for the CPU 205 to operate, and is also an image memory for temporarily storing input image data. The ROM 207 is a boot ROM and stores a system boot program. The HDD 208 is a hard disk drive, and stores system software for various processes, input image data, and the like. The operation unit I / F 209 is an interface unit for the operation unit 210 having a display screen capable of displaying image data and the like, and outputs operation screen data to the operation unit 210. Also, the operation unit I / F 209 serves to transmit information input by the user from the operation unit 210 to the CPU 205. The network I / F 211 is realized by, for example, a LAN card or the like, and is connected to the LAN N1 to input / output information to / from an external device. A modem 212 is connected to the public line 204 and inputs / outputs information to / from an external device. A CPU 205, a RAM 206, a ROM 207, an HDD 208, an operation unit I / F 209, a network I / F 211, and a modem 212 are connected on a system bus 213.

  The image bus I / F 214 is an interface for connecting the system bus 213 and an image bus 215 that transfers image data at high speed, and is a bus bridge that converts a data structure. Connected to the image bus 215 are a raster image processor (RIP) 216, a device I / F 217, a scanner image processing unit 218, a printer image processing unit 219, an image editing image processing unit 220, and a color management module (CMM) 230. Is done.

  The RIP 216 expands a page description language (PDL) data code and vector data into an image. The device I / F 217 is an interface for connecting the scanner unit 201 or printer unit 202 to the control unit 200, and performs synchronous / asynchronous conversion of image data. The scanner image processing unit 218 performs various processes such as correction, processing, and editing on the image data input from the scanner unit 201. The printer image processing unit 219 performs processing such as correction and resolution conversion according to the printer engine on the image data to be printed out. The image editing image processing unit 220 performs various types of image processing such as image data rotation and image data compression / decompression processing. The CMM 230 is a dedicated hardware module that performs color conversion processing (also referred to as color space conversion processing) on image data based on a profile and calibration data. A profile is information such as a function for converting color image data expressed in a device-dependent color space into a device-independent color space (eg, Lab). The calibration data is data for correcting the color reproduction characteristics of the scanner unit 201 and the printer unit 202 in the image processing apparatus.

<Definition of terms in this specification>
Here, definitions of terms used in this specification will be described.

  The “display list” is a common format that can be processed by the RIP, generated by conversion from various PDLs. In the display list, a drawing command indicating which object called an instruction is written in which location, edge information associated with each object, level information, fill information associated with level information, and ROP information are described. .

  “Edge” refers to a boundary between an object drawn in a page and an object or a boundary between an object and a background. The shape of the object is formed by the left and right edges. The X coordinates of the left and right edges in the scan line being processed are referred to as the left and right X coordinates.

  “Span” refers to a closed region surrounded by edges.

  “Level” indicates the vertical relationship between objects drawn in a page, and a level number is always assigned to each object. As described above, since the shape of the object is formed by the left and right edges, the vertical relationship between the edges drawn in the page is also indicated by the level.

  “Fill” means painting on the span, and there are fills with different color values for each pixel, such as Bitmap images and shading, and fills with no color value change in the span, such as solid painting. To do.

  A “scan line” is a line in the paper conveyance direction along which a scan process is executed. The height of one scan line in the two-dimensional plane is 1 pixel. A bundle of a plurality of scan lines is called a band.

  A “group” is a set in which an object or a plurality of edges forming an object are grouped in ascending level order. As an example, consider a case where there is one edge with level numbers 1 to 3001, and a maximum of 1000 edges are included in one group. In this case, the rearmost group includes edges with level numbers 1 to 1000. The next higher group includes edges with level numbers 1001 to 2000. Further, an upper group includes edges having level numbers 2001 to 3000. The highest group includes an edge having a level number of 3001. In order to maintain the hierarchical relationship of groups, each group is assigned a group number (abbreviated as group NO in this specification). For example, the group NO of the backmost group can be 1, the group NO of the group above it can be 2, and so on. The group NO is managed in the group management structure.

<About display list rendering>
FIG. 3 is a diagram illustrating a rendering process called scanline rendering. The following processing is executed by the controller 101. Specifically, the following processing is executed when the CPU 205 of the controller 101 loads and executes a scan line rendering program stored in the HDD 208 into the RAM 206.

  FIG. 3A is a block diagram illustrating a processing flow of scanline rendering processing according to the present embodiment. The scan line rendering process is roughly divided into four processes: edge processing, level processing, fill processing, and composite processing. Details of each process are described below. In addition, when CPU205 is comprised by several CPU, you may make each CPU perform a separate process. Specifically, only the edge processing is executed by the first CPU, only the level processing is executed by the second CPU, only the fill processing is executed by the third CPU, and the fourth CPU is executed. Only the composite processing may be executed.

<Edge processing>
Edge processing is roughly divided into five processes. The five processes are an edge load process, an edge deletion process, an X coordinate calculation process, an edge sort process, and an edge tracking process.

  Edge load processing refers to processing for loading edge data indicating the outline of an object onto a main memory from a display list stored in a DL (display list) memory. The edge loading process can also be referred to as a process of loading edge data into the edge list in order to manage the edge data as a link list described later.

  The X coordinate calculation process is a process for calculating the X coordinate indicating the position of the edge based on the inclination of the edge and the paint rule for each scan line with respect to the loaded edge data.

  Edges appearing on the scan line being processed are sorted in ascending order of the X coordinate from the head of the edge list for each scan line by a link list (edge list) called ActiveEdgeList (AEL). The edge data included in the edge list in the Nth scan line is sorted using the edge list in the (N−1) th scan line, which is the scan line scanned immediately before.

  Specifically, it is assumed that the edge data is sorted in the order of the edges E1, E2, and E3 according to the respective X coordinates in the edge list of the Nth scan line. When the scan line changes, the X coordinates of the edges E1, E2, and E3 on the (N + 1) th scan line are obtained by the X coordinate calculation process. Then, according to the edge list of the Nth scan line and the X coordinates of the edges E1, E2, and E3 obtained by the X coordinate calculation process, the sorting of the edges E1 to E3 is executed in the N + 1th scan line edge list.

  Here, since the edge list of the Nth scan line is sorted in the order of the edges E1, E2, and E3, first, the X coordinate of the edge E3 and the edge list of the Nth scan line are the previous one. The X coordinate of the edge E2 that was the edge is compared. Thus, it is determined whether or not the edge E3 is before the edge E2 in the edge list of the (N + 1) th scan line. When the edge E3 is before the edge E2, the X coordinate of the edge E3 is compared with the X coordinate of the edge E1 before the edge E2 in the edge list of the Nth scan line. Thus, it is determined whether or not the edge E3 is before the edge E1 in the edge list of the (N + 1) th scan line.

  Then, the order of the edge E3 in the edge list of the (N + 1) th scan line is determined according to the result of the comparison determination, and the link structure of the edge list is updated so as to be the determined order. This process is also executed for each edge, and the edge list of the (N + 1) th scan line is updated.

  When the edge X coordinates are compared, if the edge data is not on the CPU cache, it is necessary to access the edge data on the main memory. However, when the edge data is copied to the CPU cache, the processing is speeded up by accessing the edge data on the CPU cache instead of the main memory. Such an operation is a general operation of the CPU 205 connected to the CPU cache.

  As described above, it is necessary to update the link structure of the edge list when the scan line changes and the front and back of the X coordinate of the edge are reversed, when an edge newly appears, or when an edge disappears, etc. . This processing for updating the edge list is called edge sorting processing.

  The edge list after the edge sort processing is passed to the level processing unit, and the edge data and level data in the ascending order of the X coordinates are passed to the level processing unit. This processing is called edge tracking processing.

  Finally, the edge for which drawing has been completed is deleted from the memory. This processing is called edge deletion processing.

<Level processing>
Level processing is roughly divided into three processes. The three processes are a level addition process, a level deletion process, and a level sort process.

  In the level addition process, it is determined whether the edge is a drawing target edge based on the edge direction and the clip information included in the edge data sent from the edge process. When it is determined that the edge is a drawing target, the corresponding level data is added to a link list called Active Level List (ALL).

  The level deletion process is the reverse of the level addition process. In the level deletion processing, when it is determined that the edge that has been the drawing target is no longer the drawing target based on the edge direction and the clip information, the corresponding level data is deleted from the ALL.

  ALL is always sorted in ascending order of level numbers, and when there is a level addition process or a level deletion process, an ALL sort process called a level sort process is performed. The level data that has been subjected to the level addition process, the level deletion process, and the level sort process is passed to the fill process in units of spans.

<Fill processing>
The fill process is roughly divided into three processes. The three processes are an image enlargement / reduction process, an image rotation process, and a pixel generation process.

  The image enlargement / reduction process is a process for generating a color value of each pixel according to a specified enlargement ratio when an enlargement ratio is specified for a bitmap image included in the display list.

  The image rotation process is a process for generating the color value of each pixel according to the specified rotation information when the rotation information is specified in the bitmap image included in the display list.

  The pixel generation process is a process of generating the color value of each pixel according to the specified change information when change information for changing a certain color value to a certain color value is specified in the display list.

<Composite processing>
The composite process is an overlay process specified in the display list, which is executed based on the level relationship determined by the level process and the pixel value generated by the fill process.

<Edge processing, level processing, fill processing, and composite processing that are processed in parallel>
Each process described above is processed in parallel in the pipeline in units of spans. This parallel processing will be described with reference to FIGS.

  FIG. 3B shows one page image data. The object 403 is the backmost object among the objects 401 to 403, and is assigned a level number indicating that it is at the backmost. An object 402 overlaps above the object 403, and an object 401 overlaps above the object 402. These three objects are already in the display list. A scan line rendering process is performed on such page image data for each scan line.

  Explaining FIG. 3B in detail, since the first scan line of the page image data has no object, span 1-1 is processed. In the second scan line, since the object 402 exists and two edges are detected, spans 2-1, 2-2, and 2-3 are processed. In the third scan line, objects 401, 402, and 403 exist and six edges are detected, so spans 3-1, 3-2, 3-3, 3-4, 3-5, 3-6, 3-7 is processed. The same applies to the fourth and subsequent scan lines.

  As shown in FIG. 3C, the span of each scan line is pipelined in the order of edge processing, level processing, fill processing, and composite processing.

  In the example of FIG. 3B, as shown in FIG. 3C, the first span 1-1 of the first scan line is first processed by edge processing, and then passed to level processing. Next, the first span 2-1 of the second scan line is subjected to edge processing and passed to level processing, and at the same time, the span 1-1 is subjected to level processing and passed to fill processing. Similarly, as shown in FIG. 3C, each span is processed in parallel in each process.

<Edge processing for display lists that contain a large number of edges>
In FIG. 3, the rendering processing in the case where there are one object 401, 402, and 403 has been described. Here, edge sort processing in edge processing when 1000 objects 402 and 403 overlap each other will be described with reference to FIG. FIG. 4A is image data that visually shows the same image as FIG. However, in FIG. 4A, 1000 objects 402 overlap at the same position, and 1000 objects 403 overlap at the same position.

  FIG. 4B is an enlarged view of the arrangement of objects in a circle represented by a broken line near the span 3-2 in FIG. A portion represented by a vertical line in FIG. 4B is an area of the object 401. X0 is the X coordinate of the left edge of the object 401 on the fourth scan line. X1 is the X coordinate of the left edge of the object 402. X2 is the X coordinate of the left edge of the object 403. X3 is the X coordinate of the left edge of the object 401 on the third scan line. That is, when the scan line changes from the third scan line to the fourth scan line, the left edge of the object 401 crosses 1000 objects 402 and 1000 objects 403. Therefore, as illustrated in FIG. 4C, the edge data of the object 401 on the edge list of the third scan line is converted into the edge data of 1000 objects 402 and the edges of 1000 objects 403 by the edge sorting process. Trace the data. Then, the edge data of the object 401 is moved to the head of the edge list so as to be in the state of the edge list of the fourth scan line.

  That is, in FIG. 4C, as described above, edge data appearing during processing is linked as AEL in ascending X coordinate order. In the third scan line, the left edge of the object 402 is linked by 1000 links, then the left edge of the object 403 is linked by 1000 links, and finally the left edge of the object 401 is linked. ing.

  When the scan line moves from the third scan line to the fourth scan line, the X coordinate of the left edge of the object 401 changes from X3 to X0. Since X0 <X1 <X2 <X3, the left edge of the object 401 is linked to a predetermined position by following the left edge of the object 402 and the left edge of the object 403 by the edge sorting process. It will be.

  When following the link, the edge data on the main memory is sequentially accessed, and the X coordinate of each edge is compared with the X coordinate of the sorting target edge. When the number of edges is small, all the edge data accessed at least once through all the scan lines is stored in the CPU cache when accessing the edge data, so that it can be processed at high speed.

  However, when the number of edge data included in the edge list is large as in the example shown in FIG. 4, not all edge data can fit in the CPU cache. Therefore, in order to access edge data that does not exist in the CPU cache, the main memory must be accessed directly, and the processing time may be extremely slow. In particular, as shown in this example, when edges are concentrated locally (when 2000 edges are concentrated in the vicinity of the X coordinate of the left edge of the object 402), even if a few edges are moved, a large number of edges are accessed and the edges are accessed. Sort processing must be performed. This causes a problem that the processing time becomes extremely slow.

<Edge grouping process>
The edge group division processing in this embodiment will be described with reference to FIG. Here, the description will be given by taking as an example the case described in the item <edge processing of a display list including a large amount of edges>, that is, a case where 1000 objects 402 and 403 overlap each other at the same location.

  The input display list includes 1000 objects 403 assigned level numbers 1-1000, 1000 objects 402 assigned level numbers 1001-2000, and one object assigned level number 2001. 401 is included. One object consists of a left edge and a right edge. Since this display list includes 2001 objects, the number of edge data is 4002.

  Here, it is assumed that the CPU cache memory can hold up to 2000 edge data in the CPU cache, and if the number of edge data is 2001 or more, the CPU cache overflows. In this case, it is sufficient to include up to 1000 objects (corresponding to 2000 edge data) in one group. Since the “number of edge data” varies depending on the memory size of the CPU cache and the data size of the edge data, the number of edge data that can be held in the CPU cache varies depending on the image processing apparatus 100.

  First, the controller 101 determines which group each edge (edge data) should belong to by checking the edge of the object included in the input display list and the level number of this edge. In the example of FIG. 5, the edge that forms the object 403 with level numbers 1 to 1000 is in group 1, the edge that forms the object 402 with level numbers 1001 to 2000 is in group 2, and the edge that forms the object 401 is in group 3. Belongs.

  Since the bitmap to be generated for each group needs to be overlaid from the rear group, it is necessary to always render in order from the lower group (group 1 in this example). However, since the level processing is performed on the objects in each group, it is not necessary to perform the processing in ascending order of the level numbers of the objects, and the processing may be performed in the order in which edges appear.

  For the processing in each group, the rendering processing method described in the item <About display list rendering processing method> is performed. One feature of the present invention is that when interpreting the display list, only the edge data belonging to the group being processed is loaded into the main memory CPU cache for processing.

  As shown in the generation of the page image of the first group in FIG. 5, after the bitmap image is generated by the rendering processing of the first group (the upper part of FIG. 5), the processing of the second group is started. Similarly to the first group, the second group loads only the edges belonging to the second group to the CPU cache and performs rendering processing to generate a bitmap image of the second group. Then, the bitmap image of the first group and the bitmap image of the second group are overlapped to generate an image in which the bitmap image of the first group and the bitmap image of the second group are overlapped. (Middle of FIG. 5). Similarly, the rendering process and the superimposition process are repeated up to the highest group, and finally a bitmap image in which the object 402 overlaps the object 403 and the object 401 overlaps the object 402 is generated ( FIG. 5 bottom).

<Examination of composite processing after edge grouping>
The composite processing after the edge group division described with reference to FIG. 5 will be considered with reference to FIG. Composite processing includes composite processing within a group and composite processing between groups. For composite processing within a group, edges are loaded at once and level processing is performed, and levels not required for drawing are deleted, so that the minimum required composite is sufficient. On the other hand, as shown in FIG. 6, the composite processing between the groups is performed on the entire pixels between the groups, and if there are many groups, the number of composite processings between the groups increases accordingly. Therefore, when there are many groups, it may become a bottleneck of processing speed. Therefore, in order to further improve the processing speed, it is required to efficiently perform the pixel composite processing between groups.

<Composite skip processing between groups after edge grouping>
A composite skip process between groups after edge group division will be described with reference to FIG.

  Referring to FIG. 7, in the illustrated page, there is a group that includes a triangular object at the bottom, a group that includes a large square object above this group, and an opaque object at the top. There is a group that contains small square objects. When processing a certain scan line A, an opaque small rectangular object is loaded.

  This opaque opaque rectangular object is displayed without being overwritten on other objects as a final drawing result. In other words, the object below the object that is overwritten by this opaque small rectangular object is not drawn.

In this embodiment, the X coordinates (x ₁ , x ₂ ) of the left and right edges of the small opaque object that is opaque and the group number (3 in this example) of the group to which this object belongs are retained (step A in FIG. 7). -1). The object group number is assigned to each object when the objects are grouped according to the level. Further, the group numbers are set in ascending order from the lower level to the higher level. That is, an object belonging to a higher group No group may cover an object belonging to a lower group No group, but not vice versa. Specifically, for example, an object belonging to the group No. 3 may cover and overwrite an object belonging to the group No. 1. However, the object belonging to the group No. 1 does not overwrite the object belonging to the group No. 3.

After holding the X coordinate of the edge of the object and the group number of the object, the process on the next scan line B adjacent to the scan line A is executed. When the BMP generated from the back (white) and the BMP generated from the lowest group including the triangular object are composited, the back and the lowest groups are groups in which the group No. is retained in the process in step A-1. It is lower. Therefore, the inter-group composite processing is not performed in the section (x ₁ , x ₂ ) from x ₁ to x ₂ of the X coordinate (see step B-1 in FIG. 7). ).

Similarly, in the next step B-2, it is not necessary to perform the inter-group composite processing in the section (x ₁ , x ₂ ), and the inter-group composite processing is performed only in other places.

Finally, in step B-3, the section (x ₁ , x ₂ ) is overwritten by the BMP generated from the highest group, and the BMP to be finally output is generated.

<Composite skip processing flow>
The composite skip process illustrated in FIG. 7 will be described in detail with reference to FIG. A series of processing shown in FIG. 8 is executed by loading a program into the RAM in the RIP 216 in FIG. 2 and operating on the CPU in the RIP 216.

  In step S800, the process is started. Next, the process proceeds to step S802.

  In step S <b> 802, the CPU in the RIP 216 receives the display list for rendering and the number of edges included in the display list, and stores the received display list in the RAM in the RIP 216. The number of edges included in the display list is obtained by the DL generation unit counting while generating DL from PDL. In addition, in step S802, from the cache size and the data size of the edge data, the number of edges (maximum number of edges that can be included in one group) that does not cause a cache miss hit in the edge processing is calculated. The method for calculating the number of edges at which no cache miss occurs is described in the item <Method for calculating the number of edges> below. The number of groups is calculated by dividing the number of edges included in the display list by the number of edges where no cache miss occurs. Next, the process proceeds to step S803.

  In step S803, the CPU in the RIP 216 determines whether it is necessary to divide the edge into groups. Specifically, if the number of groups calculated in step S802 is greater than 1, it is determined that group division is necessary, and the process proceeds to step S809. If the number of groups calculated in step S802 is 1 or less, it is determined that group division is not necessary, and the process proceeds to step S804.

  In step S804, the CPU in the RIP 216 executes normal RIP processing that does not involve group division. Next, the process proceeds to step S820.

  In step S809, the CPU in the RIP 216 interprets the display list and loads an object. Next, the process proceeds to step S810.

  In step S810, the CPU in the RIP 216 determines whether the composite process can be omitted in an area below the loaded object, and the loaded object is opaque and rectangular, and is higher than the currently grasped object. It is determined whether or not. If it is determined that the object is opaque and rectangular and is higher than the currently recognized object, the process proceeds to step S811. If it is determined that the object is opaque and rectangular and is not higher than the currently recognized object, the process proceeds to step S812.

  In step S811, the CPU in the RIP 216 updates the group number of the group to which the object belongs and the X coordinates of the left and right edges of the object. This update process is performed by the CPU in the RIP 216 storing the group number of the group to which the object belongs and the X coordinates of the left and right edges of the object in the RAM in the RIP 216. Next, the process proceeds to step S812.

  In step S812, the CPU in the RIP 216 performs edge processing, level processing, and fill processing. Next, the process proceeds to step S813.

  In step S813, the CPU in the RIP 216 determines whether the composite process to be performed is a composite process between groups based on the group to which the object that performs the composite process belongs. If it is determined that the composite process to be performed is a composite process between groups, the process proceeds to step S815. If it is determined that the composite process to be performed is not a composite process between groups, the process proceeds to step S814. move on.

  In step S814, the CPU in the RIP 216 performs the composite process described in the <Composite process> item. Next, the process proceeds to step S818.

  In step S815, the CPU in the RIP 216 determines whether or not composite processing is performed between groups lower than the group to which the object grasped in step S811 belongs. This determination is performed by comparing the group number stored by the update in step S811 with the group number held in the RAM in the RIP 216. For example, when the group number of the object to be processed is smaller than the group number stored by the update in step S811, it is determined that the composite processing is performed between the groups lower than the group to which the object grasped in step S811 belongs. . On the other hand, when the group number of the object to be processed is larger than the group number stored by the update in step S811, it is determined that the composite processing is performed between the groups higher than the group to which the object grasped in step S811 belongs. . In the event that determination is made in step S811 that composite processing of groups lower than the group to which the object that is grasped belongs is performed, the processing proceeds to step S816. If it is determined in step S811 that the composite processing of groups lower than the group to which the object grasped is not performed is performed, the process proceeds to step S814.

  In step S816, the CPU in the RIP 216 determines whether or not composite processing between groups is performed between the X coordinates updated in step S811. Specifically, this determination is executed by comparing the section in which the composite process between the groups currently being processed is executed with the section updated in step S811. For example, assume that the X coordinate of the left edge of the object grasped in step S811 is 100, and the X coordinate of the right edge is 500. When the composite process currently being processed is executed in the section of X = 150 to 300, since the section in which the composite process is executed is included in the section grasped in step S811, the composite process of this part is It is determined that it can be omitted. If it is determined that the inter-group composite process is performed between the X coordinates updated in step S811, the process proceeds to step S818. If it is determined that composite processing between groups is not performed between the X coordinates updated in step S811, the process proceeds to step S817.

  In step S817, the CPU in the RIP 216 performs composite processing between groups. Next, the process proceeds to step S818.

  Step S818 is a loop end of processing for each object. In step S818, the CPU in the RIP 216 determines whether or not the processing of all objects on the scan line being processed has been completed. If it is determined that the processing of all objects on the scan line being processed has been completed, the processing proceeds to step S819. If it is determined that the processing of all objects in the scan line being processed has not been completed, the processing jumps to step S808, which is the loop end.

  Step S819 is a loop end of processing for each scan line. In step S <b> 819, the CPU in the RIP 216 determines whether all scan line processing for the page being processed has been completed. If it is determined that all the scan line processes on the page being processed have been completed, the process proceeds to step S820. If it is determined that all the scan line processes on the page being processed have not been completed, the process proceeds to step S820. Then, the process jumps to step S807 which is a loop end.

  In step S820, the series of processing ends.

<Edge number calculation method>
Here, a method for calculating the number of edges at which no cache miss hit occurs will be described with a specific example. For example, if the CPU cache size is 32 Kbytes and the data size of one edge data is 64 bytes, the value obtained by dividing the CPU cache size by the data size of one edge data, 512 is the number of edges at which no cache miss occurs. Become.

<Composite skip processing between groups in multiple sections>
In the first embodiment, only one section is subjected to composite skip in one scan line. However, composite skip processing may be executed for a plurality of sections in one scan line.

  A composite skip process between groups in a plurality of sections will be described with reference to FIG.

  In the page illustrated in FIG. 9, a group including a triangular object exists at the bottom, and a group including a large rectangular object exists above this group. In addition, there is a group including a medium rectangular object as a group above the group. In addition, there is a group including two non-transparent small square objects at the top.

  When processing the scan line A, two opaque small rectangular objects are loaded. Since these two opaque small square objects are finally overwritten, the objects below that overwritten by the two opaque small square objects will not be drawn.

In the present embodiment, the X coordinate and the group number of the left and right edges are held for each of the small opaque objects. Specifically, with respect to the first opaque small rectangular object, X coordinates of the left and right edges are (x ₁ , x ₂ ), and 4 is held as the group number. For the second opaque small rectangular object, the X coordinate of the left and right edges is (x ₃ , x ₄ ), and 4 is held as the group number (see step A-1 in FIG. 9).

After holding the X coordinate of the edge of the object and the group number of the object, the process on the next scan line B adjacent to the scan line A is executed. In step B-1, the BMP generated from the back surface (white) and the BMP generated from the lowest group including the triangular object are composited. At this time, the back surface and the lowest group are lower than the group holding the group number in the process in step A-1. Therefore, the inter-group composite processing is not performed in the section (x ₁ , x ₂ ) and the section (x ₃ , x ₄ ), and the inter-group composite processing is performed only in other places.

Similarly, in the subsequent steps B-2 and B-3, it is not necessary to perform the inter-group composite processing in the section (x ₁ , x ₂ ) and the section (x ₃ , x ₄ ), and only between other groups. Perform composite processing.

Finally, in step B-4, the section (x ₁ , x ₂ ) and the section (x ₃ , x ₄ ) are overwritten by the BMP generated from the highest group.

<Composite skip processing flow between groups in multiple sections>
The composite skip process in the plurality of sections illustrated in FIG. 9 will be described in detail with reference to FIG. A series of processing shown in FIG. 10 is executed by loading a program into the RAM in the RIP 216 in FIG. 2 and operating on the CPU in the RIP 216. A series of processing according to the present embodiment is partially the same as the processing according to the first embodiment. Specifically, with respect to the processing of steps S800 to S809 and the processing of steps S812 to S820 of FIG. 8, the processing of the present embodiment is the same as the processing of the first embodiment. Therefore, in the following description, the description of the same processing as that in the first embodiment is omitted, and the processing after step S1001 after step S1000 (S809 in FIG. 8) will be described.

  In step S1001, the CPU in the RIP 216 determines whether the composite process can be omitted in the area below the loaded object, and the loaded object is opaque and rectangular, and is higher than the currently grasped object. It is determined whether or not. If it is determined that the object is opaque and rectangular and is higher than the currently grasped object, the process proceeds to step S1002. If it is determined that the object is opaque and rectangular and is not higher than the currently recognized object, the process advances to step S1005.

  In step S1002, the CPU in the RIP 216 determines whether or not the number of sections to be subjected to composite skip processing between groups is within the number that can be held. The number of sections that can be retained and subjected to composite skip processing between groups is set in advance. If the number of sections targeted for composite skip processing between groups is within the number that can be held, the process proceeds to step S1003. If the number of sections to be subjected to composite skip processing between groups is larger than the number that can be held, the processing proceeds to step S1004.

  In step S1003, the CPU in the RIP 216 additionally registers the group number to which the object acquired when loading the edge belongs and the X coordinates of the left and right edges of the object. Next, the process proceeds to step S1005 (S812 in FIG. 8).

  In step S1004, the CPU in the RIP 216 deletes the data related to the object closest to the back surface among the held objects, and additionally registers the data related to the object loaded in step S1001. Specifically, the group number to which the object acquired when loading the edge belongs and the X coordinates of the left and right edges of the object are additionally registered. Next, the process proceeds to step S1005 (S812 in FIG. 8).

<Composite skip processing with optimal object selection>
In the above-described embodiment, the composite skip process between groups is executed in the span of the opaque object belonging to the highest group. However, depending on the shape of the object, the composite skip processing between groups may be executed in the span of the opaque object belonging to the lower group than the highest group.

  With reference to FIG. 11, a composite skip process between groups with selection of an optimal object will be described.

  In the page illustrated in FIG. 11, a group including a triangular object exists at the bottom, and a group including a large rectangular object exists above this group. In addition, there is a group including a non-transparent middle square object as a group above the group. Further, there is a group including a small opaque object that is opaque at the top.

  When processing the scan line A, an opaque small square object belonging to the highest group is loaded. However, since the quadrangle drawn by this object is smaller than a predetermined size, in this embodiment, the object is not set as a reference for executing the composite skip. In the present embodiment, a non-transparent medium rectangular object belonging to a lower group of the highest group is set as a reference for executing composite skip. Any objects below it that are overwritten by this opaque medium square object will not be drawn.

In the present embodiment, the X coordinate and group No. of the left and right edges are held for a medium square object. Specifically, (x ₁ , x ₂ ) is held as the X coordinate of the left and right edges, and 3 is held as the group number.

After holding the X coordinate of the edge of the object and the group number of the object, the process on the next scan line B adjacent to the scan line A is executed. In step B-1, the BMP generated from the back surface (white) and the BMP generated from the lowest group including the triangular object are composited. At this time, the back surface and the lowest group are lower than the group holding the group number in the process in step A-1. Therefore, the inter-group composite processing is not performed in the section (x ₁ , x ₂ ), and the inter-group composite processing is performed only in other places.

Similarly, in the subsequent step B-2, it is not necessary to perform the inter-group composite processing in the section (x ₁ , x ₂ ), and the inter-group composite processing is performed only in other places.

Similarly, in the subsequent step B-3, overwriting is performed without performing composite processing between groups in the section (x ₁ , x ₂ ).

  Finally, in step B-4, the small rectangle is overwritten. At this time, composite processing between groups is performed. However, since the span of a small square object is short, the edge processing does not require much time.

<Composite skip processing flow with optimal object selection>
With reference to FIG. 12, the composite skip process involving selection of the optimum object illustrated in FIG. 11 will be described in detail. A series of processing shown in FIG. 12 is executed by loading a program into the RAM in the RIP 216 in FIG. 2 and operating on the CPU in the RIP 216. A series of processing according to the present embodiment is partially the same as the processing according to the first embodiment. Specifically, with respect to the processing of steps S800 to S809 and the processing of steps S812 to S820 of FIG. 8, the processing of the present embodiment is the same as the processing of the first embodiment. Therefore, in the following description, the description of the same processing as in the first embodiment is omitted, and the processing after step S1201 after step S1200 (S809 in FIG. 8) will be described.

  In step S1201, the CPU in the RIP 216 determines whether the composite process can be omitted in the area below the loaded object, and the loaded object is opaque and rectangular, and is higher than the currently recognized object. It is determined whether or not. If it is determined that the loaded object is opaque and rectangular and is higher than the currently recognized object, the process proceeds to step S1202. If it is determined that the loaded object is opaque and rectangular and is not higher than the currently grasped object, the process proceeds to step S1204.

  In step S1202, the CPU in the RIP 216 determines whether the size of the loaded object is larger than a predetermined size (whether the span length of the loaded object is longer than a predetermined length). If it is determined that the size of the loaded object is larger than the predetermined size, the process proceeds to step S1203. If it is determined that the size of the loaded object is equal to or smaller than the predetermined size, the process is performed. The process proceeds to step S1204 (S812 in FIG. 8).

  In step S1203, the CPU in the RIP 216 updates the group number of the group to which the object belongs and the X coordinates of the left and right edges of the object. Next, the process proceeds to step S1204 (S812 in FIG. 8).

<Composite skip processing between groups in non-rectangular object spans>
In the embodiment described above, the composite skip process between groups is executed in the span of a rectangular object. However, composite skip processing between groups may be executed in a span of an object other than a rectangle.

  A composite skip process between groups in a span of an object other than a rectangle will be described with reference to FIG.

  In the page illustrated in FIG. 13, a group including a triangular object exists at the bottom, and a group including a large rectangular object exists above this group. In addition, a group including an opaque trapezoidal object exists at the top.

  When processing the scan line A, an opaque trapezoidal object belonging to the highest group is loaded. Since the object is finally overwritten by the opaque trapezoidal object, the object below the overwriting portion is not drawn.

In this embodiment, the X coordinate and group No. of the left and right edges are held for the opaque trapezoidal object. Specifically, (x ₁ , x ₂ ) is held as the X coordinate of the left and right edges, and 3 is held as the group number. In addition, when performing the edge processing of the trapezoidal object, the span (x ₁ ′, x ₂ ′) in the next scan line B adjacent to the scan line A is also held (see step A-1 in FIG. 13).

Next, processing in the scan line B is executed. In step B-1, the BMP generated from the back surface (white) and the BMP generated from the lowest group including the triangular object are composited. At this time, the back surface and the lowest group are lower than the group holding the group number in the process in step A-1. Therefore, the inter-group composite processing is not performed in the section (x ₁ ′, x ₂ ′), and the inter-group composite processing is performed only in other places.

Similarly, in the subsequent step B-2, it is not necessary to perform the inter-group composite processing in the section (x ₁ ′, x ₂ ′), and the inter-group composite processing is performed only in other places.

Finally, in step B-3, the section (x ₁ ′, x ₂ ′) is overwritten by the BMP generated from the highest group.

<Composite skip processing flow for spans of objects other than rectangles>
The composite skip process in the span of an object other than the rectangle illustrated in FIG. 13 will be described in detail with reference to FIG. A series of processing shown in FIG. 14 is executed by loading a program into the RAM in the RIP 216 in FIG. 2 and operating on the CPU in the RIP 216. A series of processing according to the present embodiment is partially the same as the processing according to the first embodiment. Specifically, with respect to the processing of steps S800 to S809 and the processing of steps S813 to S820 in FIG. 8, the processing of the present embodiment is the same as the processing of the first embodiment. Therefore, in the following description, the description of the same processing as that in the first embodiment will be omitted, and the processing after step S1401 after step S1400 (S809 in FIG. 8) will be described.

  In step S1401, the CPU in the RIP 216 determines whether or not the loaded object is higher than the object that is opaque and currently grasped in order to determine whether the composite processing can be omitted in the area below the loaded object. Determine. If it is determined that the loaded object is opaque and higher than the currently recognized object, the process proceeds to step S1402. If it is determined that the loaded object is not transparent and not higher than the currently recognized object, the process advances to step S1403.

  In step S1402, the CPU in the RIP 216 updates the group number of the group to which the object belongs and the X coordinates of the left and right edges of the object. Next, the process proceeds to step S1403.

  In step S1403, the CPU in the RIP 216 determines whether it is edge processing of the held object. If it is determined that the process is an edge process for a held object, the process proceeds to step S1404. If it is determined that the process is not an edge process for a held object, the process proceeds to step S1405.

  In step S1404, the CPU in the RIP 216 calculates and holds the X coordinate of the edge of the object in the next scan line. Next, the process proceeds to step S1405.

  In step S1405, the CPU in the RIP 216 performs edge processing, level processing, and fill processing. Next, the process proceeds to step S1406 (S813 in FIG. 8).

<Simple composite skip processing for spans of objects other than rectangles>
In Example 4, the section (x ₁ ′, x ₂ ′) to be skipped in the next line was calculated for each line in the process on the currently processed line. However, in this embodiment, the composite processing is executed by setting the spans (x ₁ , x ₂ ) due to the left and right edges of the once loaded object as a section in which composite skip can always be performed. Note that this embodiment assumes a case where the left edge of the object extends in the x-axis minus direction and the right edge extends in the x-axis plus direction when processing proceeds from one scan line to the next. ing.

  A simple composite skip process between groups in a span of an object other than a rectangle will be described with reference to FIG.

  In the page illustrated in FIG. 15, a group including a triangular object exists at the bottom, and a group including a large rectangular object exists above this group. In addition, there is a group including trapezoidal objects that are small and opaque at the top.

  When processing the scan line A, an opaque trapezoidal object belonging to the highest group is loaded. When proceeding from scan line A processing to scan line B processing, the left edge of the opaque trapezoid proceeds in the x-axis minus direction, and the right edge proceeds in the x-axis plus direction. In the present embodiment, the object is finally overwritten by the opaque trapezoidal object, so that the object below the overwritten portion is not drawn.

In the present embodiment, for the loaded trapezoidal object, the uppermost span and the group number among the spans by the left and right edges are held. Specifically, (x ₁ , x ₂ ) is retained as the span, and 3 is retained as the group number. As can be seen from FIG. 15, the span (x ₁ , x ₂ ) represents the upper base of the trapezoid.

Next, processing in the scan line B is executed. In step B-1, the BMP generated from the back surface (white) and the BMP generated from the lowest group including the triangular object are composited. At this time, the back surface and the lowest group are lower than the group holding the group number in the process in step A-1. Therefore, the inter-group composite processing is not performed in the section (x ₁ , x ₂ ) held in step A-1, and the inter-group composite processing is performed only in other places.

Similarly, in the subsequent step B-2, it is not necessary to perform the inter-group composite processing in the section (x ₁ , x ₂ ), and the inter-group composite processing is performed only in other places.

  Finally, in step B-3, the object is overwritten by the opaque trapezoidal object.

<Simple composite skip processing flow for spans of objects other than rectangles>
The simple composite skip process in the span of an object other than the rectangle illustrated in FIG. 15 will be described in detail with reference to FIG. A series of processing shown in FIG. 16 is executed by loading a program into the RAM in the RIP 216 in FIG. 2 and operating on the CPU in the RIP 216. A series of processing according to the present embodiment is partially the same as the processing according to the first embodiment. Specifically, with respect to the processing of steps S800 to S809 and the processing of steps S812 to S820 of FIG. 8, the processing of the present embodiment is the same as the processing of the first embodiment. Therefore, in the following description, the description of the same processing as in the first embodiment is omitted, and the processing after step S1601 after step S1600 (S809 in FIG. 8) will be described.

  In step S1601, the CPU in the RIP 216 determines whether or not the loaded object is higher than the object that is opaque and currently grasped. Also, the CPU in the RIP 216 is a trapezoid in which the left edge extends in the x-axis minus direction and the right edge extends in the x-axis plus direction when the current scan line advances to the next scan line for the loaded object. Is determined based on the inclination of the edge. If all of these conditions are satisfied, the process proceeds to step S1602, and if none of these conditions is satisfied, the process proceeds to step S1603 (S812 in FIG. 8).

  In step S1602, the CPU in the RIP 216 holds the group number of the group to which the object belongs and the X coordinates of the left and right edges of the loaded object. Next, the process proceeds to step S1603 (S812 in FIG. 8).

<Relationship between edge grouping and prior art>
The relationship between the edge group division processing according to the present invention and the prior art will be described with reference to FIG. A series of processing shown in FIG. 17 is executed by loading a program into the RAM in the RIP 216 in FIG. 2 and operating on the CPU in the RIP 216.

  As described in the first embodiment, the edge group division process is a process in which the display list is input and the bitmap is output, and the edge is determined based on the CPU cache size and the edges included in the display list. This process is performed by dividing into groups.

  Further, “fallback” appearing in this description is the processing described in the background art. When the data size of the input PDL data is large, the memory size for generating the display list may be insufficient. In this case, a display list having a size that fits in the memory size is generated from the PDL data and rendered. A display list is generated so that the remaining PDL data for which the display list could not be generated at once also fits in the memory size. If there is already rendered data, superimposition is performed.

  The PDL rendering process starts in step S1701. Next, the process proceeds to step S1703.

  In step S1703, the CPU in the RIP 216 receives the PDL for rendering and stores it in the RAM in the RIP 216. Next, the process proceeds to step S1704.

  In step S1704, the CPU in the RIP 216 interprets the PDL and generates a display list. Next, the process proceeds to step S1705.

  In step S1705, the CPU in the RIP 216 determines whether a fallback has occurred in the page being processed. If it is determined that a fallback has occurred, the process proceeds to step S1706. If it is determined that no fallback has occurred, the process proceeds to S1709.

  In step S1706, the CPU in the RIP 216 performs rendering processing after dividing the edges into groups. Next, the process proceeds to step S1707.

  In step S1707, the CPU in the RIP 216 performs page overlay processing. Details of the page overlay processing will be described in the <Fallback overlay processing> item. Next, the process proceeds to step S1708.

  In step S1708, the CPU in the RIP 216 determines whether or not all the input one page of PDL processing has been completed. If it is determined that all the input PDL processes for one page have been completed, the process proceeds to step S1711. If it is determined that all of the input PDL processes for one page have not been completed, the process is Return to step S1704.

  In step S1709, the CPU in the RIP 216 performs rendering processing after dividing the edge into groups. Next, the process proceeds to step S1711.

  In step S1711, the CPU in the RIP 216 determines whether all the PDL processes for all input pages have been completed. If it is determined that all the input PDL processes for all pages have been completed, the process proceeds to step S1712, and if it is determined that all the input PDL processes for all pages have not been completed, the process is Return to step S1704.

  The PDL rendering process ends in step S1712.

<Overlay processing in fallback>
Here, the page overlay processing in step S1707 of FIG. 17 will be described. In the page overlay processing in fallback, when a rendering image for one page is generated, the rendering processing unit compresses the generated bitmap to reduce the data size, and the compressed bitmap is converted to the background image DL. Is stored in the DL memory. In other words, the display list generation unit to which the region information is sent generates the next display list so that the compressed bitmap is included as the background. When the display list includes a background image, the rendering processing unit expands the compressed image and performs a superimposition process when rendering the display list currently being processed as a background image.

  On the other hand, in step S814 and step S817 in FIG. 8 described above, the generated rendering image is held without being compressed by the rendering processing unit, and is superimposed on the rendering image of the lower group when rendering the next group. Therefore, in this respect, the overlay process in the fallback is different from the composite process in step S814 or step S817 in FIG. 8 described above.

<Other embodiments>
Although various embodiments have been described in detail above, the present invention may be applied to a system constituted by a plurality of devices, or may be applied to a single device. For example, the present invention can be applied to a scanner, a printer, a PC, a copier, a multifunction peripheral, a facsimile machine, and a system combining these.

  The present invention supplies a software program that implements the functions of the above-described embodiments directly or remotely to a system or apparatus, and a computer included in the system reads and executes the supplied program code. Can also be achieved.

  Accordingly, since the functions and processes of the present invention are implemented by a computer, the program code itself installed in the computer also implements the present invention. That is, the computer program itself for realizing the functions and processes is also one aspect of the present invention.

  In that case, the computer program only needs to have the function of the program, and the form of the program such as an object code, a program executed by an interpreter, script data supplied to the OS, etc. is not limited.

  Examples of the recording medium for supplying the program include a flexible disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, and CD-RW. Examples of the recording medium include a magnetic tape, a nonvolatile memory card, a ROM, a DVD (DVD-ROM, DVD-R), and the like.

  The program may be downloaded from an Internet / intranet website using a browser of a client computer. That is, the computer program itself of the present invention or a compressed file including an automatic installation function may be downloaded from the website onto a recording medium such as a hard disk. The present invention can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading the respective files from different websites. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer may be a constituent requirement of the present invention.

  Further, the program of the present invention may be encrypted and stored in a storage medium such as a CD-ROM and distributed to users. In this case, only the user who has cleared the predetermined condition is allowed to download the key information to be decrypted from the website via the Internet / intranet, decrypt the program encrypted with the key information, and execute the program. You may install it on

  Further, the functions of the above-described embodiments may be realized by the computer executing the read program. Note that an OS or the like running on the computer may perform part or all of the actual processing based on the instructions of the program. Of course, also in this case, the functions of the above-described embodiments can be realized.

  Furthermore, the program read from the recording medium may be written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Based on the instructions of the program, the CPU or the like provided in the function expansion board or function expansion unit may perform part or all of the actual processing. In this way, the functions of the above-described embodiments may be realized.

Claims (9)

An image processing device that generates a bitmap for a display list and executes a rendering process,
Loading means to interpret the display list and load the object;
A determination means for determining whether the loaded object is opaque and is higher than the currently grasped object;
When the loaded object is opaque and is higher than the currently grasped object, the group number of the group to which the loaded object belongs and the coordinates of the left and right edges of the object in the currently processed scan line are stored. Holding means;
When the composite process is a composite process between groups and is executed between groups lower than the group to which the highest-level object currently grasped belongs, the composite process is performed within the section represented by the coordinates of the left and right edges. An image processing apparatus comprising: skipping means for skipping. The determination means determines whether or not the loaded object is a trapezoid based on an inclination of an edge,
The holding means holds the group number of the group to which the loaded object belongs and the coordinates of the left and right edges of the object when the loaded object is opaque and trapezoidal and is higher than the currently grasped object. The image processing apparatus according to claim 1, wherein: Means for calculating the number of edges in which a cache miss hit does not occur in edge processing, and calculating the number of groups into which edges are divided based on the calculated number of edges;
The image processing apparatus according to claim 1, further comprising: a unit that determines whether to divide the edge into groups based on the calculated number of groups. The determination means determines whether the loaded object is opaque and rectangular and is higher than the currently grasped object,
When the loaded object is opaque and rectangular and is higher than the currently grasped object, the holding means includes the group number of the group to which the loaded object belongs and the right and left of the object in the scan line currently being processed. The image processing apparatus according to claim 1, wherein coordinates of edges of the image are held. Means for determining whether or not the number of sections subject to composite skip processing between groups is within a holdable number when the loaded object is opaque and is higher than the currently known object; ,
If the number of sections subject to composite skip processing between groups is not within the number that can be retained, delete the data related to the object closest to the back of the objects held, and the data related to the loaded object The image processing apparatus according to claim 1, further comprising: a registering unit.   If the loaded object is opaque and is higher than the currently known object, and the size of the loaded object is greater than a predetermined size, the holding means The image processing apparatus according to claim 1, wherein the group number of the group to which the image belongs and the coordinates of the left and right edges of the object in the scan line currently being processed are held.   When the edge process is an edge process of an object that holds the coordinates of the left and right edges, the apparatus further comprises means for holding the coordinates of the left and right edges of the object in the scan line next to the scan line currently being processed The image processing apparatus according to claim 1. An image processing method for generating a bitmap for a display list and executing a rendering process,
Interpreting the display list and loading the object;
Determining whether the loaded object is opaque and higher than the currently known object;
When the loaded object is opaque and is higher than the currently grasped object, the group number of the group to which the loaded object belongs and the coordinates of the left and right edges of the object in the currently processed scan line are stored. Steps,
When the composite process is a composite process between groups and is executed between groups lower than the group to which the highest-level object currently grasped belongs, the composite process is performed within the section represented by the coordinates of the left and right edges. An image processing method comprising: a step of skipping.   A program for causing a computer to function as the image processing apparatus according to any one of claims 1 to 7.

Images