JP2006031160A - Graphic object processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the deterioration of a processing speed to be caused by pipeline stall due to processing concentration on an arbitrary module or function in a rendering device configured by the pipeline connection of respective exclusive hardware for side processing, active object determination, in-span pixel value determination and final pixel value determination. <P>SOLUTION: An arbitration algorithm at the time of bus access by respective modules configuring a pipeline is changed according to load relations between those respective modules so as to prevent or reduce stall, or to reduce the influence of stall. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for rendering object graphic elements into a raster pixel image, and in particular, such object graphics that do not use frame or line storage of pixel data as part of the rendering process. The present invention relates to a rendering apparatus that performs efficient rendering on pixel image data of elements.

  Most object-based graphics systems use a frame store or page buffer to hold a pixel-based image of the page or screen. Typically, the outline of a graphic object is calculated, filled and written to the frame store. In the case of two-dimensional graphics, the object in front of other objects is simply written to the frame store after the background object is written, thereby replacing the background on a pixel-by-pixel basis. This is commonly known in the art as “Paint's algorithm”. Objects are considered in order of priority, from the deepest object to the foremost object, usually with each object rasterized in scan line order, with pixels in a sequential sequence along each scan line. Written to the frame store.

  There are basically two problems with this technique. The first problem is that fast random access to all pixels in the frame store is required. This is because each newly considered object can affect any pixel in the frame store. For this reason, the frame store is usually held in a semiconductor random access memory (RAM). For high resolution color printers, the amount of RAM required is very large, typically over 100 Mbytes, which is costly and difficult to operate at high speed. The second problem is that many pixels are painted (rendered) and overpainted (re-rendered) by objects later in time. Painting pixels with the previous object in time is time consuming.

  One way to overcome the large frame store problem is the use of “banding”. When using banding, only a portion of the frame store is in memory at a time. All of the objects to be drawn are saved in the “display list store”. The entire image is rendered in the same manner as above, but pixel painting (rendering) operations that attempt to paint (render) outside the existing portion of the frame store are “clipped” out. After all of the objects have been drawn, the portion of the frame store is sent to the printer (or other location), another portion of the frame store is selected, and this process is repeated. This technique comes with a penalty. For example, the object being drawn must be reviewed and re-examined many times (once per band). As the number of bands increases, the inspection of objects that need to be rendered is repeated and the number of times increases. Banding techniques do not solve the problem of overcoating costs.

  In some other graphics systems, the images are examined in scan line order. Again, all of the drawn objects are saved in the display list store. On each scan line, the objects that intersect that scan line are considered for each object in order of priority, and the span of pixels between the intersections of the object's sides is set in the line store. This technique also overcomes the problem of large frame stores, but still suffers from overcoating problems.

  Other than these, there are techniques that solve both the large frame store problem and the overcoat problem. In one such technique, each scan line is created in turn. Again, all of the drawn objects are saved in the display list store. In each scan line, the side of the object that intersects the scan line is held in ascending order of the coordinates of the intersection with the scan line. These intersection points or edge intersections are considered in turn and used to toggle the array of active flags. There is one active flag for each object priority of interest on that scan line. Between each of the edge pairs considered, the color data for each pixel between the first edge and the next edge is at the highest priority, using the priority encoder for the active flag And using the color associated with that priority for the pixels of the span between the two sides. In preparation for the next scan line, the coordinates of the intersection of each side are updated according to the nature of each side. Adjacent edges that are missorted as a result of this update are swapped. New sides are also merged into the list of sides.

  This technique has the great advantage that there is no frame store or line store, no overcoat, and object priority is processed in constant order times rather than N times the order (where N is the number of priorities). Have. However, this technique is extremely limited in its use because it cannot perform the many functions required by existing graphic description languages.

  Techniques have been proposed that substantially overcome or at least improve one or more deficiencies associated with this technique (see, for example, US Pat.

In this technique, each scan line is created in turn. First, all objects to be drawn are sorted and stored in the display list store in the order of scan lines where drawing of each object is started. For each scan line, the sides of the object that intersect the scan line are maintained in ascending order of intersection coordinates, and for each adjacent pair of these side intersections, the information associated with the corresponding object is examined, and the side intersection Determine a set of active objects for a span of pixel positions between corresponding pairs of pixels, and for each of the spans of pixel positions, use the corresponding set of active objects to determine the value of each position in the span. decide.
JP 2000-149035 A

  However, in implementing the above technique, edge processing, active object determination, determination of pixel values within a span, and determination of a single pixel value from the pixel values of multiple active objects are realized by dedicated hardware. It is realized by connecting the hardware to form a pipeline, or the entire processing is realized on the host by software. In this case, in hardware implementation, when a certain image is rendered by the hardware of a given pixel sequential rendering device, processing is concentrated on an arbitrary module or function depending on the characteristics of the image, and pipeline installation occurs. However, the processing speed may be limited.

  The present invention has been made in order to solve the above-described problems, and its purpose is to avoid stalls by processing in parallel processing between hardware and software for functions that are heavily loaded in rendering processing. It is to provide a pixel sequential rendering device that is reduced and faster.

  In order to solve the above problem, in the graphic object processing method according to the first aspect of the present invention, in the method of processing a display list of graphic objects to form a raster pixel image, the display list is analyzed and the display list is displayed. Means for adding a flag; means for determining a flag added to the display list; first processing means for executing processing for the table dilith when the determination result flag is not set; and And a second processing means for executing means equivalent to the first processing means when the result flag is set.

  In the graphic object processing method according to the second aspect of the present invention, the step of analyzing the display list and adding a flag to the graphic object is further executed by software.

  In the graphic object processing method according to the third aspect of the invention, the first processing means is hardware, and the second processing means is a processor and software executable by the processor.

  In the graphic object processing method according to the fourth aspect of the present invention, the means for adding a flag particularly adds the flag by analyzing the configuration of the display list and the first processing means.

  In the graphic object processing method according to the fifth aspect of the present invention, the display list is further composed of graphic object property information and an instruction stream defining processing for the graphic object property information.

  In the graphic object processing method according to the sixth aspect of the invention, the means for adding a flag particularly analyzes the property information of the graphic object.

  In the graphic object processing method according to the seventh aspect of the present invention, the means for adding a flag particularly analyzes the instruction stream.

  In the graphic object processing method according to the eighth aspect of the present invention, in the step of analyzing the display list and adding a flag to the graphic object, a flag is set for an arbitrary command.

  In the graphic object processing method according to the ninth aspect of the present invention, in the step of analyzing the display list and adding a flag to the graphic object, a flag is set for property information of an arbitrary graphic object. .

  In the graphic object processing method according to the invention of claim 10, the first processing means further includes means for reading a display list, means for determining on / off of a flag set in the display list, and second processing. Means for transferring a display list record related to the flag, and the second processing means has means for receiving the display list record from the first processing means. .

  In the graphic object processing method according to the eleventh aspect of the present invention, the first processing means further includes a plurality of processing means.

  In the graphic object processing method according to the twelfth aspect of the present invention, the first processing means is configured by connecting a plurality of processing means in a pipeline.

  In the graphic object processing method according to the thirteenth aspect of the present invention, the first processing means further includes processing means for reading the display list and generating an internal command for defining an operation in the first processing means. To do.

  The graphic object processing method according to the fourteenth aspect of the present invention is further characterized in that the internal command has a field reserved for a flag.

  In the graphic object processing method according to the fifteenth aspect of the present invention, the processing means for reading the display list and generating an internal command for defining an operation in the first processing means is configured such that the flag is included in the records included in the display list. A flag is set for an internal command related to the set record.

  In the graphic object processing method according to the sixteenth aspect of the present invention, further, at least one of the plurality of processing means constituting the first processing means reads the field reserved for the flag of the internal command Means for determining the flag, means for assigning processing to the processing means itself according to the flag, means for assigning processing to the second processing means according to the flag, and And a second processing means having means for receiving an internal command from the first processing means and means for executing processing for the command received from the first processing means. It is characterized by.

  The graphic object processing method according to claim 17 further includes means for reading a field reserved for a flag of an internal command among a plurality of processing means constituting the first processing means, and the flag. Means for determining, means for assigning processing to the processing means itself according to the flag, means for assigning processing to the second processing means according to the flag, means for transferring the internal command to the second processing means The processing means further includes means for receiving a response to the internal command from the second processing means, and the second processing means is a means for issuing a response to the process after executing the process for the internal command. It is characterized by having.

  In the graphic object processing method according to the eighteenth aspect of the present invention, the second processing means further includes processing means for reading the display list and generating internal commands for defining operations of the first processing means and the second processing means. It is characterized by including.

  The graphic object processing method according to the present invention is further characterized in that the internal command has a field reserved for a flag.

  In the graphic object processing method according to the twentieth aspect of the present invention, the display list further includes processing means for reading the display list and generating internal commands for defining operations in the first processing means and the second processing means. A flag is set for an internal command related to a record in which the flag is set among the records.

  In the graphic object processing method according to claim 21, the second processing means further includes means for reading a field reserved for a flag included in an internal command, means for determining the flag, In accordance with the flag, means for assigning processing to the second processing means itself, means for selecting an arbitrary processing means among the processing means constituting the first processing means according to the type of internal command, and the flag Means for assigning a process to the selected processing means of the first processing means, and means for transferring the internal command to the selected processing means of the first processing means. The plurality of processing means constituting the means has means for receiving an internal command from the second processing means.

  In the graphic object processing method according to the twenty-second aspect of the present invention, the second processing means further executes processing for the internal command in the selected processing means of the first processing means after executing processing for the internal command assigned to itself. It has means for issuing an end notice, and the plurality of processing means constituting the first processing means have means for receiving a process end notice for the internal command from the second processing means.

  In the graphic object processing method according to the twenty-third aspect, the means for adding a flag to the display list changes the order in the display list.

  In the graphic object processing method according to a twenty-fourth aspect of the present invention, the means for adding a flag to the display list changes the order of the instructions.

  As described above, according to the present invention, the display list store is pre-scanned to estimate the processing function that becomes a bottleneck from the hardware configuration and the characteristics of the image to be processed, and an arbitrary one in the display list store. By adding additional information to the instruction and executing the process corresponding to the instruction with the additional information in software, the bottleneck process in the drawing process is executed in parallel between the hardware and software, thereby reducing the drawing process time. Provided is a pixel sequential rendering apparatus capable of

  The apparatus of the present invention and its operation will be described in detail below.

  FIG. 1 schematically illustrates a computer system 10 configured for rendering and presentation of computer graphic object images. The system includes a host processor 11 associated with a system random access memory (RAM) 12, which includes a non-volatile hard disk drive or similar device and a volatile semiconductor. RAM can be included. The system 10 also includes a system read only memory (ROM) 13, which is usually based on a semiconductor ROM and can often be supplemented by a compact disk device (CD-ROM). System 10 may also incorporate means 14 for displaying images, such as a video display unit (VDU) or printer operating in a raster fashion.

  The components described above with respect to system 10 are interconnected via bus system 15 and are well known in the art, such as IBM PC / AT type personal computers and configurations developed therefrom, Sun Sparcstations and the like. It can operate in the normal operating mode of the computer system.

  As also illustrated in FIG. 1, the pixel sequential rendering device 16 is derived from a graphic object-based description that is connected to the bus 15 and supplied with instructions and data from the system 10 via the bus 15. Configured for sequential rendering of pixel-based images. The pixel sequential rendering device 16 can use the system RAM 12 for rendering the object description, but may also implement and use a dedicated local memory.

  FIG. 2 is a diagram showing a basic function data flow. The functional flow diagram of FIG. 2 begins with an object graphic description 21. This object graphic description 21 is generated by the host processor 11, stored in the system RAM 12, or provided by the system ROM 13, and is used to describe the parameters of the graphic object from which the pixel-based image is derived. Can be interpreted by the pixel sequential rendering device 16. For example, the object graphic description 21 includes an orthogonal side format in which a two-dimensional object is defined by a side of a straight line (simple vector) crossing from one point on the display to another point or a plurality of sides including orthogonal lines. Objects with edges can be incorporated in several formats including: Apart from this, formats in which objects are defined by continuous curves are also suitable, including several parameters that allow a quadratic curve to be rendered in a single output space without having to perform multiplication. Can contain a quadratic polynomial line that can describe a single curve. Other data formats such as cubic splines and the like can be used. An object can contain a mixture of many different edge types. Usually common to all formats is the identifier of the start and end of each line (whether straight or curved), which are usually identified by a scan line number, and hence the curve A specific output space that can be rendered is defined.

  Having identified the data necessary to describe the graphic object to be rendered, the graphic system 10 performs a display list generation step 22.

  The display list generator 22 is preferably implemented as a software module that runs on the host processor 11 having the ROM 13 and RAM 12 attached. The display list generator 22 converts an object graphic description expressed in one or more of a well-known graphic description language, graphic library call or other application specific format into a display list. The display list is normally written in the display list store 23. The display list store 23 is generally formed in the RAM 12, but may instead be formed in a memory that the pixel sequential rendering device 16 has locally. The display list store 23 can include a plurality of components, one of which is an instruction stream and the other is edge information, which can include raster image pixel data.

  The instruction stream includes code that can be interpreted as instructions that are read by the pixel sequential rendering device 16 to render the particular graphic object desired in the particular image.

  The display list store 23 is read by the pixel sequential rendering device 16. The pixel sequential rendering device 16 converts the display list into a stream of raster pixels, which can be transferred to another device such as a printer, display or memory store, for example.

  FIG. 3 is a configuration diagram of a pixel sequential rendering apparatus that processes a display list obtained from the object graphic description 21 to generate pixels.

  The pixel sequential rendering apparatus of FIG. 3 can take a plurality of configurations by selecting the addition of a plurality of hardware modules to the basic configuration, and the functional compatibility between the basic configuration and the hardware configuration with additional expansion. And a mechanism for guaranteeing functional compatibility between hardware configurations with different additional extensions. More specifically, it has a mechanism for autonomously executing software on the difference in hardware configuration. In FIG. 3, 301 to 308 are basic configuration modules, and 310 to 313 are additional expansion modules.

  In the display list, the drawing objects included in the original object / graphic description are sorted and recorded in ascending order of the sub-scanning line direction (y-coordinate). In addition, the side information of each object is stored as a side table. The relationship (calculation method) between the correlated level information and pixels at the same coordinates on other levels is included as a level table, and information for determining the color inside the object is included as a fill table. In addition, as data for determining the color of an object, data and processing for generating a color are specified, and reading a bitmap or decompressing a compressed image, and capturing an arbitrary pixel from the result. It may be specified.

In FIG. 3, reference numeral 300 denotes a pixel sequential rendering apparatus, which includes modules 301 to 308 and 310 to 313 described later (of which 301 to 306 are referred to as pipeline modules), and 301 accesses the system bus. An instruction execution unit that reads the display list, interprets the instruction stream, and issues an internal command to a subsequent pipeline module composed of 302 to 305 described later. 302 is an internal issued by the instruction execution unit 301 According to the command, the side information included in the display list is read, the side information of the drawing object is extracted in units of scanning lines, the side information is sorted in ascending order of the scanning line direction (x coordinate), and then the latter part of the pipeline to be described later The edge information is sent to the 303 level priority determination section. The edge processing unit 303 transfers as a page, and 303 reads the level table included in the display list and the edge information generated by the edge processing unit 302 in accordance with the instruction issued by the instruction execution unit 301. The priority of each level and the activated pixel range (influencing drawing) are determined every time, and the information of the activated pixel range of each scanning line is sorted in the order of priority. Is a level priority determining unit that transfers pixel range information to the fill data determining unit 304 located in the later stage of the pipeline, which is later described in the pipeline, and 304 is an internal number issued by the instruction execution unit 301. According to the command, the fill table included in the display list and the pixel range information generated by the level priority determination unit 303 are read, and the level Fill data for determining the color of the activated pixel and transferring the color information of the activated pixel together with the pixel range information transferred from 303 to a color synthesis unit 305 located in the later stage of the pipeline, which will be described later A determination unit 305 includes pixel range information of each level generated by the level priority determination unit 303 according to an internal command issued by the instruction execution unit 301 and pixel color information determined by the fill data determination unit 304. And a color composition unit that performs an operation for determining a color for each pixel and generates a final color of the pixel,
Reference numeral 306 denotes a pixel output unit that sends the final pixel generated by the color composition unit 305 to the connected external device. Reference numeral 307 denotes the above-described side processing unit 302, level priority determination unit 303, and fill data determination. A compatibility guarantee unit that processes the internal command by software intervention when an internal command requiring a function that is not implemented in the unit 304 and the color synthesis unit 305 is issued by the instruction execution unit 301. A bus access arbitration unit that arbitrates and orders access to the system bus by the unit 302, the level priority determination unit 303, the fill data determination unit 304, the color composition unit 305, and the compatibility guarantee unit 307, and relays the access to the system bus. is there.

  An extension component can be added to each of the side processing unit 302, the level priority determination unit 303, the fill data determination unit 304, and the color composition unit 305, and an image expansion unit for the fill data determination unit 304. 310 can be added, and the image expansion unit 310 can further add an extended part. The expansion as described above is performed according to the performance and cost required for the system.

  Reference numeral 310 denotes an image expansion unit that is an extension module that supports, for example, JPEG, which makes it possible to handle a compressed image when determining a pixel color, and reference numeral 311 denotes an edge processing extension unit that is an extension module corresponding to PostScript. Reference numeral 312 denotes an edge processing extension unit that is an extension module corresponding to GDI, and reference numeral 313 denotes an image expansion extension unit that is an extension module corresponding to JBIG.

  Further, the image decompression unit 310 performs its own processing if it is compatible with the image decompression unit 310, issues a command to the compatibility guarantee unit 307 if the processing is not supported, and receives an end command for the issued command. Finally, a process end notification is issued to the fill data determination unit 304.

  In the following, an outline of the operation of the pixel sequential rendering apparatus of FIG. 3 will be described by taking an example of processing an object graphic description corresponding to an image as shown in FIG. FIG. 4 shows a drawing screen in which a triangular object 41 is first drawn (level 1) and an elliptical object 42 is drawn on top of it (level 2). Level 0 represents, for example, a default level farthest from the viewpoint corresponding to paper when an image is printed, and has a default background color such as white.

Prior to processing by the pixel sequential rendering device of FIG. 3, the object graphic description is converted into a display list by software. The display list includes at least the following information.
(1) Draw from y = 30 to y = 140.
(2) From y = 30 to y = 140, there are straight sides indicating the start of the area of the object 41. Including tilt.
(3) From y = 30 to y = 140, there are straight sides indicating the end of the area of the object 41. Including tilt.
(4) From y = 70 to y = 115, there is an elliptical arc side indicating the start of the area of the object 42. To be precise, the elliptical arc is divided into short straight segments and is included with information on the starting position and slope of each segment.
(5) From y = 70 to y = 115, there is an elliptic arc side indicating the end of the area of the object 42. To be precise, the elliptical arc is divided into short straight segments and is included with information on the starting position and slope of each segment.
(6) The level (z coordinate) information of the object 41 and the relationship (calculation) with the pixel of the same coordinate at another level, whether the color information of the object at the lower level (far side with respect to the viewpoint) is necessary (that is, transmission) Or impervious) and how the color is determined within the level (fill type).
(7) The level (z coordinate) information of the object 42 and the relationship (calculation) with the pixel of the same coordinate at another level, whether the color information of the object at the lower level (the far side with respect to the viewpoint) is necessary (that is, transmission) Or impervious) and how the color is determined within the level (fill type).
(8) Pointer information from (2) to (6).
(9) Pointer information from (3) to (6).
(10) Pointer information from (4) to (7).
(11) Pointer information from (5) to (7).
(12) Information for determining (filling) the color of the object 41.
(13) Information for determining (filling) the color of the object 42.
(14) Pointer information from (6) to (12) (15) Pointer information from (7) to (13) (16) Side table address (17) Level table address (18) Fill table address

  Of these, (2), (3), (4), (5), (8), (9), (10) and (11) are included in the side table, and (6), (7), ( 12) and (13) are included in the level table, and (14) and (15) are included in the fill table. The display list store is stored in a memory area starting from a predetermined address.

  When the pixel sequential rendering apparatus 300 receives an activation instruction, the instruction execution unit 301 reads a display list from a predetermined address. The processing start and drawing area are notified to each module downstream of the pipeline by an internal command, the edge processing unit 302 is notified of the edge table address (16) by the internal command, and the level priority determining part 303 is notified of the level table address. (17) is notified by the internal command, and the fill data determining unit 304 is notified of the fill table address (18) by the internal command. At this point, each module in the pipeline, that is, the edge processing unit 302, the level priority determination unit 303, the fill data determination unit 304, and the color synthesis unit 305, receives a predetermined internal command from a module located upstream of the pipeline. It will be in a standby state. Next, the instruction execution unit 301 issues a drawing start command to the side processing unit 302, the level priority determination unit 303, the fill data determination unit 304, and the color composition unit 305.

  The edge processing unit 302, the level priority determination unit 303, the fill data determination unit 304, and the color synthesis unit 305 generate default (background color) pixels from y = 0 to y = 30 if necessary. The edge processing unit 302 and the level priority determination unit 303 start processing from y = 30, and the fill data determination unit 304 uses the default, that is, the background level as processing for the region from y = 0 to y = 30. In contrast, a background color is generated for all the pixels in the scanning line direction, and the pixel having the background color passes through the color synthesis unit 305 (without inter-pixel calculation processing) as a final pixel via the pixel output unit 306. Is output.

  The edge processing unit 302 skips to y = 30, detects the occurrence of two edges belonging to the object 41 from y = 30, registers the two edges in the edge table, and starts tracking. Since these two sides belong to the same object, they are already sorted in the x order, and are directly notified to the level priority determination unit 303 by an internal command.

  The level priority determination unit 303 activates level 1 between the two sides, reads the level 1 attribute from the level table, issues an internal command, and fills the x coordinate of the two sides and the level 1 attribute. The data determination unit 304 is notified.

  The fill data determination unit 304 searches the fill table according to the level 1 attribute, determines the color of the pixel between the two sides according to the fill table information and the level attribute, and notifies the color composition unit 305 of each pixel. In addition, for a region that is not between the two sides, a default color is generated and notified to the color composition unit 305 as in the case of y = 0 to y = 30.

  Since the color synthesizing unit 305 does not need to perform pixel calculation processing between a plurality of levels, the pixel received from the fill data determining unit 304 is directly output as the final pixel.

  The edge processing unit 302 starts tracking two edges belonging to an elliptical object from y = 70. Here, since the two sides added later are located at coordinates where x is larger than the side of the triangle object 41, it is not necessary to sort the sides. Since the two objects 41 and 42 do not overlap, the level priority determination unit 303, the fill data determination unit 304, and the color composition unit 305 operate in substantially the same manner from y = 30 to y = 69.

  The side information needs to be sorted in the scanning line after the side of the triangle object 41 and the side of the ellipse object 42 intersect. Also, since the objects have overlap, a plurality of levels are activated for the same pixel, and an operation for determining the pixel is performed. This situation will be described by taking a process for a scanning line of y = 85 as an example.

  The edge processing unit 302 monitors the intersection of the edges in the process of tracking the edges, and once the intersection occurs, the tracking is continued according to the order after the intersection. Therefore, at y = 85, the side of the triangle object 41 and the side of the ellipse object 42 already intersect, and the x coordinate of the side is updated in the order of x0, x1, x2, and x3, and is notified to the level priority determination unit 303. .

  The level priority determination unit 303 activates only level 1 from x0 to x1, activates level 1 and level 2 from x1 to x2, and activates level 1 and level 2 from x2 to x3. Only 2 is activated. If the transmittance of the ellipse object 42 is 0, only level 1 is activated from x0 to x1, and only level 2 is activated from x1 to x3. Hereinafter, the description will be continued for the case where the transmittance of the ellipse object 42 is not zero. The level in the active state and the edge information on both ends are notified to the fill data determination unit 304.

  The fill data determination unit 304 generates a default color of a default level from x = 0 to x = x0, generates a color of a level 1 pixel from x0 to x1 according to a level 1 attribute, and levels from x1 to x2 A level 1 pixel color according to the 1 attribute, a level 2 pixel color according to the level 2 attribute, and a level 2 pixel color according to the level 2 attribute from x2 to x3, For the pixels from x3 to the right end of the drawing size, a default color of a default level is generated and transferred to the color composition unit 305 in pixel order.

  The color composition unit 305 outputs the pixel color received from the fill data determination unit 304 as it is between x = 0 and x1, and the level 2 color for the level 1 color in the level table for x1 to x2. The final pixel color is output by applying and applying the specified operation described above, and the pixel color received from the fill data determining unit 304 is output as it is for the pixels from x2 to the right end of the drawing size. To do. However, there is a case where nothing is done for the default color in the above processing.

  The above processing is executed in a pipeline manner. That is, each module of the instruction execution unit 301, the edge processing unit 302, the level priority determination unit 303, the fill data determination unit 304, and the color composition unit 305 receives an internal command from the module that executes the next processing when its processing is completed. Is issued to request processing, and when the next processing becomes possible, the internal command from the module that executes the previous processing is accepted. If processing is being executed internally, or if the buffer is full and new processing cannot be accepted, a busy state is notified through a path to the module that executes the previous processing, and notification that processing is not accepted. The module notified of the busy state cannot transfer the internal command to the module that executes the subsequent processing, and a stall occurs.

  In the above description, a case has been described in which an image that requires only functions supported by the hardware with the basic configuration shown in FIG. 3 is processed. For example, if the side processing unit 302 is compatible only with OpenPage, the display list store generated based on the OpenPage drawing information has been processed. Here, for example, when a display list / store generated based on the PostScript drawing information is specified, the hardware, that is, the side processing unit 302 cannot correctly process, so the compatibility guarantee unit 307 receives an internal command. Is transferred. The compatibility guarantee unit 307 reads an appropriate routine from a set of processing routines for internal commands not supported by hardware stored in a system memory (not shown) connected via the system bus, and executes the internal command. The processing result is transferred to the system memory or the internal command transfer source module, and the end of the processing is notified to the internal command transfer source module. When the internal command transfer source module receives the notification of the end of the processing, it issues an internal command to the module that executes the subsequent processing as if it had processed it, and continues the processing. As described above, an arbitrary display list / store can be processed even if the hardware does not necessarily support all the drawing functions.

  Here, as shown in FIG. 5, when a plurality of objects 51 to 55 drawn with the same scanning line as a starting point are drawn, and each object is filled with a JPEG image, the scanning line (FIG. 5) is drawn. In the process (indicated by a dotted line in FIG. 5), the expansion process must be performed to determine fill information for each pixel of each object. However, JPEG decompression processing is difficult to process in a few clock cycles even if hardware is used. Therefore, when handling an image as shown in FIG. 5, the input of the fill data determination unit 304 becomes busy and the pipeline can stall. High nature. Rather than sequentially performing decompression on all the images 51 to 55 by the same hardware, for example, only the decompression processing of 55 may be performed at a higher speed when executed in parallel by software. Such a determination can be analyzed or estimated to some extent from the hardware configuration information of the pixel sequential rendering apparatus and the input image data.

  The function flow at this time is shown in FIG. 7 shows the details of the pre-scan flow, FIG. 8 shows the processing flow of the instruction execution unit 301, and FIG. 9 shows the processing flow of the image decompression unit 310. Reference between the display list, command, and memory The relationship is shown in FIG. In addition, at least a 1-bit flag field is reserved for each instruction of the instruction stream of the display list and an internal command of the pixel sequential rendering apparatus, and the flag is extended so that the flag is not set up. And

  In order to support parallel execution by hardware and software, the computer system 10 further pre-scans the display list, extracts an object that starts on the same scan line and requires decompression processing, and decompresses the fill information of the object. Means for adding a flag for instructing decompression by software (61 in FIG. 6 and FIG. 7), and the instruction execution unit 301 has an equivalent meaning when the decompressed instruction to which the flag is added is read. Means for outputting an internal command for image expansion with the flag added to the pipeline module (FIG. 8), and the image expansion unit 310 transfers the image expansion command with the flag added to the compatibility assurance unit 307. And means for receiving a response to the image decompression command from the compatibility guarantee unit 307 ( 9), in guarantee compatibility unit 307 further has a means for issuing to the image decompression unit 310 responding processes the image decompression command.

  A procedure for adding a software processing flag to the display list will be described with reference to FIG. First, a file describing the hardware configuration of the pixel sequential rendering apparatus 300 is read from the system RAM 12 or system ROM 13 via the bus 15 (71), the display list 23 is read from the system RAM 12 or local memory (72), and the number of objects And a positional relationship is extracted (73), a function that is likely to concentrate the load is estimated based on 71 and 73 (74), and a function that concentrates the load occurs (75). An instruction in the instruction stream to be identified is determined (76), a software processing flag is added (77), and if a function that concentrates addition does not occur (75), the process ends.

  FIG. 10 shows the reference relationship between the display list 23, the internal command, and the system RAM 12 at this time. It is assumed that the display list 23 includes an instruction stream 101, edge information 102, and fill information 103. Each instruction in the instruction stream has a processing type, a processing target that is a side record or a filled record depending on the processing type, a parameter for processing, and a software processing flag. The edge information is composed of segment records representing one graphic object with a plurality of records, and each segment record has a start (x, y) coordinate, an end y-coordinate, and a segment inclination dx necessary for generating edge information. And a level to which the segment belongs, a pointer to a segment that is continuous from the end coordinates and represents the same graphic object, and other parameters used in the algorithm for determining the color and coordinates. Each record of the fill information stores the fill type, the color information in the case of filling with the same color, the address in which the bitmap is stored in the case of a bitmap, and the compressed image in the case of a compressed image. Address, a buffer address for storing decompressed data, and properties such as decompression parameters. For example, when filling with a compressed image mapped in the system RAM 12 in FIG. 10, the display list 23 is given as a source the address where the compressed image is stored as a record of the filling information, and stores the decompressed data. It includes a filled record given an address, a segment record associated with the filled record, and a decompression command and a fill command for processing the filled record. Based on these data, the decompression command given as an address where the compressed image is stored as a source address, and given as a destination address the leading address of the buffer for storing the decompressed data, and the decompressed data as By generating a paint command given with the start address of the buffer for storing as a source address, it is possible to paint a graphic object to be processed with a desired color. When the software processing flag is set in the decompression instruction, the flag is set in the software processing flag field of the decompression command, and the decompression processing is transferred to the compatibility guarantee unit 107 and processed.

  The flow of operations related to the software processing flag of processing in the instruction execution unit 301 will be described with reference to FIG. First, an instruction stream is read from the display list 23 (81), and if the read instruction has a software processing flag (82), a command with a software processing flag is generated (83), and the read instruction has a software processing flag. If not (82), a normal command is generated (84).

  The flow of operations related to the software processing flag of processing in the image expansion unit 310 will be described with reference to FIG. However, a case where the content of the received command can be realized by a function supported by the image expansion unit 310 will be described. First, a command is received from the pixel data determination unit 304 (91), and if it is a normal command (92), the processing is performed by itself (93), and if it is a command with a software processing flag (92), the compatibility guarantee unit 307 receives the command. The command is transferred (94), the response command from the compatibility guarantee unit is received (95), and finally the response command is returned to the pixel data determination unit 304 (96).

  By adding the functions as described above, the image decompression command without the flag is transferred from the paint data determination unit 304 to the image decompression unit 310 and subjected to hardware processing. The data is transferred to the compatibility guarantee unit 307 and processed by software. By appropriately adding the flag, image expansion processing is executed in parallel by hardware and software, and the overall processing time is shortened.

  Furthermore, in the pre-scan, for instructions scheduled to be processed by software, the order of instructions is changed so that commands are issued as early as possible in consideration of the time required for processing by hardware. Depending on the situation, it may be possible to improve the performance.

  The means for adding a flag for instructing the image expansion by the software to the display list can be executed at the same time when the display list is generated. However, the number of objects and the mutual positional relationship can be substantially extracted. Such a case is also included in the pre-scan.

  Image decompression may be started simultaneously with the start of the page drawing process, asynchronously with other pipeline processes. In this case, even if the JPEG image object does not start on the same scanning line, it is possible to mix expansion by software.

Rendering system configuration diagram Functional flow in the rendering system Configuration diagram of pixel sequential rendering device Drawing object example Drawing object example Functional flow in the rendering system Software processing flag generation flow Flow of command generation with software processing flag Flow of control using commands with software processing flags Reference relationship between display list, internal command and system RAM

Explanation of symbols

10 Rendering system
11 CPU
12 RAM
13 ROM
14 Image output device
15 bus
16 pixel sequential rendering device
21 Object graphic description
22 Display list generation
23 Display List Store
24 −
25 pixel output
300 pixel sequential rendering device
301 Instruction execution part
302 Side processing part
303 Priority determination unit
304 Pixel data decision unit
305 Color composition part
306 Pixel output section
307 Compatibility Assurance Department
308 Bus Access Mediation Department
309 −
310 Image expansion
311 PostScript compatible edge processing extension
312 GDI compatible edge processing extension
313 JBIG compatible image expansion and extension
41 drawing objects
42 drawing objects
51 JPEG drawing objects
52 JPEG drawing objects
53 JPEG drawing objects
54 JPEG drawing objects
55 JPEG drawing objects
61 Prescan
71 Hardware configuration reading step
72 Display list / store read step
73 Object information analysis step
74 High load function estimation step
75 High load function presence / absence judgment step
76 High-load function / object determination step
77 Software processing flag addition step
81 Instruction reading step
82 Software processing flag judgment step
83 Command generation step with software processing flag
84 Normal command generation step
91 Command reception step
92 Software processing flag judgment step
93 Image expansion processing steps
94 Command Transfer Step to Compatibility Assurance Department
95 Response command reception step from complementarity assurance
96 Response command issue step for image expansion command
101 instruction stream
102 Edge information
103 Fill information
104 Decompress command
105 Fill command

Claims (24)

  In a method of processing a display list of graphic objects to form a raster pixel image, means for analyzing the display list and adding a flag to the display list, means for determining a flag added to the display list, and the determination First processing means for executing processing on the table ground squirrel when the result flag is not set, and means equivalent to the first processing means when the determination result flag is set And a graphic object processing method.   2. The graphic object processing method according to claim 1, wherein means for analyzing the display list and adding a flag to the graphic object is implemented as software.   2. The graphic object processing method according to claim 1, wherein the first processing means is hardware, and the second processing means is a processor and software executable by the processor.   4. The graphic object processing method according to claim 3, wherein the means for adding a flag adds a flag by analyzing the structure of the display list and the first processing means.   2. The graphic object processing method according to claim 1, wherein the display list includes property information of the graphic object and an instruction stream that defines processing for the property information of the graphic object.   6. The graphic object processing method according to claim 5, wherein the means for adding a flag particularly analyzes the property information of the graphic object.   6. The graphic object processing method according to claim 5, wherein the means for adding a flag particularly analyzes an instruction stream.   6. The graphic object processing method according to claim 5, wherein in the step of analyzing the display list and adding a flag to the graphic object, a flag is set for an arbitrary instruction.   6. The graphic object processing method according to claim 5, wherein in the step of analyzing the display list and adding a flag to the graphic object, a flag is set for property information of an arbitrary graphic object. .   2. The graphic object processing method according to claim 1, wherein the first processing means reads the display list, the means for determining on / off of the flag set in the display list, and the second processing means to the flag. Graphic object processing method, wherein the second processing means includes means for receiving the display list record from the first processing means. .   2. The graphic object processing method according to claim 1, wherein the first processing means further comprises a plurality of processing means.   12. The graphic object processing method according to claim 11, wherein the first processing means is constituted by connecting a plurality of processing means in a pipeline connection.   13. The graphic object processing method according to claim 11, wherein the first processing means includes processing means for reading the display list and generating an internal command for defining an operation in the first processing means. Graphic object processing method.   14. The graphic object processing method according to claim 13, wherein the internal command has a field reserved for a flag.   15. The graphic object processing method according to claim 14, wherein the processing means for reading the display list and generating an internal command for defining an operation in the first processing means is a record in which the flag is set among records included in the display list. A graphic object processing method characterized in that a flag is set for an internal command related to.   16. The graphic object processing method according to claim 15, wherein at least one of a plurality of processing means constituting the first processing means reads a field reserved for a flag included in an internal command, and the flag Means for allocating processing to the processing means itself according to the flag, means for allocating processing to the second processing means according to the flag, and transferring the internal command to the second processing means And the second processing means includes means for receiving an internal command from the first processing means and means for executing processing for the command received from the first processing means. Graphic object processing method.   17. The graphic object processing method according to claim 16, wherein means for reading a field reserved for a flag of an internal command among a plurality of processing means constituting the first processing means, and means for determining the flag A means for assigning a process to the processing means itself according to the flag; a means for assigning a process to the second processing means according to the flag; and a means for transferring the internal command to the second processing means. The means further includes means for receiving a response to the internal command from a second processing means, and the second processing means includes means for issuing a response to the process after executing the process for the internal command. Characteristic graphic object processing method.   13. The graphic object processing method according to claim 11, wherein the second processing means includes processing means for reading the display list and generating an internal command for defining operations of the first processing means and the second processing means. A graphic object processing method comprising:   19. The graphic object processing method according to claim 18, wherein the internal command has a field reserved for a flag.   20. The graphic object processing method according to claim 19, wherein the processing means for reading the display list and generating an internal command for defining an operation in the first processing means and the second processing means is the record included in the display list. A graphic object processing method characterized by setting a flag for an internal command related to a record for which a flag is set.   21. The graphic object processing method according to claim 20, wherein the second processing means reads means reserved for a flag included in an internal command, means for judging the flag, and second means according to the flag. Means for assigning processing to the processing means itself, means for selecting an arbitrary processing means among the processing means constituting the first processing means according to the type of internal command, and the first processing according to the flag Means for allocating processing to the selected processing means of means, and means for transferring the internal command to the selected processing means of the first processing means, constituting the first processing means The graphic object processing method, wherein the plurality of processing means includes means for receiving an internal command from the second processing means.   22. The graphic object processing method according to claim 21, wherein the second processing means issues a processing end notification for the internal command to the selected processing means of the first processing means after executing the processing for the internal command assigned to itself. And a plurality of processing means constituting the first processing means include means for receiving a processing end notification for the internal command from the second processing means.   2. The graphic object processing method according to claim 1, wherein the means for adding a flag to the display list changes the order in the display list.   6. The graphic object processing method according to claim 5, wherein the means for adding a flag to the display list changes the order of instructions.

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