JP4522216B2 - Image processing device - Google Patents

Description

The present invention receives the page description language data, and relates to an image processing equipment for generating and outputting image data.

  An image processing apparatus that inputs data described in a page description language and rasterizes it to generate an image is known. According to the image processing apparatus, semantics (semantic analysis) of the input page description language is performed, and then Two procedures of rendering processing are performed. Typical algorithms for realizing this rendering process include a painter algorithm and a scan line algorithm. In a conventional image processing apparatus, after semantic processing of input data described in a page description language, image processing is performed by a hardware device or software device that implements the algorithm. The major difference in the hardware configuration for executing these algorithms is the required memory capacity, and the scan line algorithm is a rendering algorithm that uses a small memory capacity among these algorithms.

  In a rendering device that executes such an algorithm, an edge process that tracks the edge of each object and sorts the edges of the X coordinate, a level process that processes the display position level of each object, a color generation process, an image process, a color A processing unit called a basic rendering processing unit having a plurality of processing modules such as compositing processing is provided, and this basic rendering processing unit is composed of a plurality of modules, and each module is pipeline-connected for image processing. Necessary processing is performed sequentially.

Regarding a processing method and a control method of each processing module, Patent Document 1 discloses a graphic object processing method and apparatus for high-speed raster format rendering. According to this, the basic rendering processing unit performs various parameter settings and rendering processing in the pipeline processing module in accordance with an instruction issued based on the result of analyzing the page description language. In addition, a plurality of extended software modules responsible for some of these processing modules are provided, and each extended software module includes a CPU therein and provides a function of rendering with software.
JP 2000-149035 A

  However, the above-described conventional image processing apparatus is not configured to stop or execute the operation of the processing module to be used according to the function to be used. Therefore, low power consumption according to the function to be used. Could not be realized. In the page description language, there are functions that are used and functions that are not used depending on input data. For example, it is useless to leave a character processing module in an operating state for input data only for graphics. In particular, the CPU of the above-described extended software module includes a cache, a RAM, and the like therein, and consumes a large amount of power. However, the conventional image processing apparatus has a problem that power is wasted because there is no function of specifying the type of input data and operating only the extended software module necessary for processing the input data.

The present invention has been made in view of the above problems, it is to provide an image processing equipment which is to suppress the entire electric power consumption.

An image processing apparatus according to an aspect of the present invention has the following configuration. That is,
An image processing apparatus for inputting page description language data, generating and outputting image data,
An analysis means for analyzing the input page description language data;
Rendering means for rendering the page description language data based on the analysis by the analysis means;
A plurality of extension software modules that execute a part of the rendering function by the rendering means, each of which includes a CPU;
Determining means for determining whether or not the page description language data includes an instruction to be processed by an extended software module;
Based on the determination result by the determining means, a clock signal is supplied to the CPU of the corresponding extended software module among the plurality of extended software modules, and a signal indicating that the clock is supplied to the CPU is transmitted to the analyzing means . Control means;
Output processing means for inputting the image data rendered by the rendering means and outputting the image data to an output device, and supplying a signal indicating that rendering by the rendering means is completed to the control means,
When the analysis means receives a signal indicating that a clock is supplied to the CPU from the control means, the rendering means starts rendering by the rendering means,
The control means stops the supply of a clock to the CPU upon receiving a signal indicating that the rendering has been completed .

  According to the present invention, power consumption can be reduced by supplying a clock signal to a module necessary for rendering page description language data.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing an example of an image processing apparatus according to Embodiment 1 of the present invention.

  The semantic analysis unit 1 analyzes the content of the received page description language data and issues a command to the rendering processing unit 2. For this command, for example, various parameter setting processing or conversion from graphics data to bitmap data can be considered. The rendering processing unit 2 is composed of a plurality of modules, and each module is connected in a pipeline and sequentially processes processes necessary for image processing. Functions of this pipeline module include an edge processing unit 3 that tracks the edges of each object and sorts X-coordinate edges, a level processing unit 4 that processes the display position level of each object, and a color generation that performs color generation. There are a processing unit 5, an image processing unit 6 for processing image data, a color composition unit 7 for performing color composition, and the like.

  The output processing unit 8 inputs the image data rendered by the rendering unit 2 and outputs the image data to an output device 9 such as a printer or a display device.

  The extension software modules 60 and 61 have CPUs 24 and 27, respectively, and realize the functions of the corresponding processing units of the rendering processing unit 2. Reference numerals 21 to 23 denote interface units that are provided in the extended software module 60 and control interfaces with the edge processing unit 3, the level processing unit 4, and the color generation unit 5. Similarly, reference numerals 25 to 26 denote interface units that are provided in the extended software module unit 61 and manage the interfaces with the image processing unit 6 and the color synthesis unit 7.

  The PDL prefetch unit 40 prefetches the input page description language data, checks whether the input data includes an instruction that needs to be processed by the extended software modules 60 and 61, and transmits the result to the clock control unit 41. Based on the result from the PDL prefetch unit 40, the clock control unit 41 supplies a clock (50, 51) to the CPU of the extended software module that needs to be processed. Thereafter, a clock switching end signal 52 is transmitted to the semantic analysis unit 1.

  When the semantic analysis unit 1 receives the clock switching end signal 52 from the clock control unit 41, the semantic analysis unit 1 supplies various parameter setting commands and graphic processing commands to the rendering processing unit 2. Thus, the rendering process is started. When the rendering process ends, a rendering process end signal 53 is supplied from the output processing unit 8 to the clock control unit 41. The clock control unit 41 that has received the rendering end signal 53 stops supplying the clocks to the CPUs 24 and 27 of all the extended software modules until the next image processing is started.

  FIG. 2 is a flowchart for explaining processing of the image processing apparatus according to Embodiment 1 of the present invention.

First, in step S101, the language analysis block of the semantic analysis unit 1 performs language analysis of the input page description language data. Next, in step S102, it is determined whether or not the above-described clock switching has been completed. If the clock switching has not been completed, step S102 is executed until the clock switching is completed. When the clock switching is thus completed, the process proceeds to step S103, where the input page description language is converted into a parameter setting instruction and an internal processing instruction based on the language analysis in step S101. In step S104, the instruction generated in step S103 is, whether it is possible to process in the pipeline module is determined, if possible processing in a pipelined modules is processed in step S105. If it is determined that processing cannot be performed by the pipeline module, processing is performed by the extended software module in step S106. After executing step S105 or S106 in this way, the process proceeds to step S107 to perform data output processing. In step S108, the supply of the clock to the expansion module is stopped.

  In parallel with the language analysis processing in step S101 described above, in step S112, the PDL prefetch unit 40 fetches the input page description language, and in step S113, an instruction that requires processing in the extended software modules 60 and 61. Is included in the input data, and the result is transmitted to the clock control unit 41. In this way, the clock control unit 41 executes the clock switching process for supplying the clock (50, 51) to the CPU of the extended software module that needs to be processed based on the result from the PDL prefetch unit 40. It is determined in step S102 whether or not this switching process has been completed, and the above-described process is executed.

  FIG. 3 is a flowchart for explaining details of the clock switching processing according to the first embodiment.

  First, in step S121, the presence / absence of input data is determined. If there is input data, input data prefetch processing is performed in step S122. In step S123, the syntax of the prefetched input data is analyzed to search for a function necessary for input data processing. Next, in step S124, it is checked whether there is a function to be processed by the extended software module based on the search result. If there is no need to process in the extended software module, a clock switching process end signal is sent in step S126. Output. On the other hand, if it is necessary to perform processing by the extended software module, a clock is supplied to the CPU of the corresponding extended software module in step S125, and a clock switching process end signal is output in step S126.

  If it is determined in step S121 that there is no input data, the process advances to step S127 to determine whether or not there is a rendering process end signal. If there is a rendering process end signal, in step S128, the CPU of all the extended software modules is sent to the CPU. Stop supplying the clock.

  FIG. 4 is a diagram for explaining a module configuration example of the basic rendering processing unit 2 and the extended software module of the image processing apparatus according to Embodiment 1 of the present invention.

  In the figure, for example, the extended software module No. 1 connected to the edge processing unit of the basic rendering module includes “Bitmap Font” (bitmap font), “FastBitmapEncoding” (high-speed bitmap encoding), “Bezier” (Bézier), It can be seen that “DirectSorting” can be processed. The number (No) assigned to the extended software module indicates the number assigned to each software module.

  The data input to the image processing apparatus according to the first embodiment is data described in a page description language. In this embodiment, PostScript, which is a typical language as a page description language, is used. A case of Bezier curve processing will be described. Hereinafter, a general description of Bezier curves and description examples of Bezier curves in PostScript will be described.

  A Bezier curve is one of the control methods used to draw a curve, and Postscript supports Bezier curves controlled from four points. A Bezier curve controlled from four points is a curve that starts at point A, is controlled by B and C, and ends at point D. A Bezier curve having four points A, B, C, and D as control points is generated by the following equation. A, B, C, and D are position vectors, and t is [0. . 1] is a cubic expression with t as a parameter.

r (t) = A. (1-t) 3 + 3B.t. (1-t) 2 + 3C.t2. (1-t) + D.t3
From this equation, r (t) = A when t = 0, r (t) = D when t = 1, and as t changes from 0 to 1, the value of r (t) becomes A> It changes in the order of B>C> D. The following properties are listed as the properties of the Bezier curve.

  1. A Bezier curve falls within a four-point convex polygon.

  2. The straight lines AB and CD are tangent to the curve at the start and end points of the curve.

3. Let P, Q, and R be the midpoints of line segments AB, BC, and CD, respectively. Line P-Q, Q-R a midpoints of, respectively it S, T, when the midpoint of the line segment S-t and W, W is the point of the Bezier curve in t = 1/2. In general, a point W obtained by dividing each line segment by a ratio of m: n is a point of a Bezier curve.

  FIG. 5 is a diagram visually representing the middle point W (t = 1/2) of the Bezier curve having four control points. The control points A (38, 120) and B (54) in the above Bezier curve formula are shown. 136), C (82, 143), and D (104, 134).

  FIG. 6 is a diagram showing PostScript commands describing this Bezier curve.

  “38 120 moveto” in the third line in FIG. 6 means that the current coordinate is moved to (38, 120) as the control point A, and “54 136 82 143 104 134 curveto” in the fourth line is the control point. A point B (54, 136), a control point C (82, 143), and a control point D (104, 134) are set to instruct to draw a Bezier curve. The above is the general description of the Bezier curve and the description method of the Bezier curve in Postscript.

  As is clear from this example, if the operator “curveto” representing the Bezier curve is included in the postscript, it can be determined that the Bezier curve is drawn without considering other conditions.

  Therefore, the PDL prefetch unit 40 fetches PDL data from the designated main memory address and analyzes the meaning of the page description language data. If an operator that matches “curveto” is included, it is determined that the target data includes a Bezier curve, and the determination result is transmitted to the clock control unit 41. Thereby, the clock control unit 41 recognizes that the extension software module corresponding to the Bezier curve is the extension software module No1 with reference to the table shown in FIG. Then, the clock 50 is supplied to the extended software module No 1 and a clock supply end signal 52 is transmitted to the semantic analysis unit 1.

  The semantic analysis unit 1 interprets the input page description language data and generates a command for the basic rendering processing unit 2. The command generated in this way includes simple processing such as loop processing and condition determination, numerical calculation, parameter setting, and the like. Further, the semantic analysis unit 1 outputs the generated instruction to the basic rendering processing unit 2 after the clock switching end signal from the clock control unit 41 is asserted. If the command generated here is parameter setting, the parameter is set in a predetermined table. If the generated instruction relates to rendering processing, processing is performed in each pipeline module in the basic rendering processing unit 2 (step S105). Furthermore, if the generated rendering instruction cannot be processed by each pipeline module, the instruction is issued to the extension software module (step S106). Thus, each extended software module decodes the received rendering instruction and processes the rendering instruction by software.

  If the instruction input to the edge processing unit 3 is Bezier curve processing, the edge processing unit 3 supplies the instruction to the extension software module (S125). In this embodiment, since the extended software module No1 is a module that performs Bezier curve processing (FIG. 4), when the extended software module No1 decodes the received instruction and determines that the data is an instruction related to Bezier, Perform software processing.

  At this time, the operation is not executed because the clock is not supplied to the extension software module not related to the input data processing among the other extension software modules connected to the pipeline module. When the command generated by the semantic analysis unit 1 is a command related to output processing, printing processing or screen output is performed by outputting data stored in the output processing unit 8 to the output device 9. At the same time, the output processing unit 8 supplies a rendering processing end signal 53 to the clock control unit 41. Thus, after receiving the rendering process end signal 53, the clock control unit 41 stops supplying the clocks to the CPUs of all the extended software modules (step S108).

[Embodiment 2]
FIG. 7 is a block diagram for explaining the configuration of the image processing apparatus according to the second embodiment of the present invention. The parts common to those in FIG.

  In the figure, the extended rendering module unit 11 includes extended hardware module units 12, 13, 14, 15, 16, 17, 18, and 19 and an extended software module unit 20.

  The PDL prefetch unit 40 prefetches the input page description language data, searches the input data for an instruction that requires processing in the extended rendering module unit 11, and supplies the search result to the clock control unit 41. . Based on the search result, the clock control unit 41 supplies a clock to the corresponding block in the extended rendering module unit 11, and then transmits a clock switching end signal to the semantic analysis unit 1. When the semantic analysis unit 1 receives the clock switching end signal from the clock control unit 41, it transmits various parameter setting commands and graphic processing commands to the rendering processing unit 2 and starts processing.

  Each of the extended hardware module units will be described. 12 is a bitmap font module, 13 is a Bezier processing module, 14 is a block rendering module, 15 is a bitmap module, 16 is a linear lamp module, 17 is a JPEG module, 18 Is a JBIG module, and 19 is a PDF module.

  Further, in the second embodiment, the extended software module unit 20 is composed of one module, and each of 21 to 26 includes an edge processing unit 3, a level processing unit 4, a color generation unit 5, an image processing unit 6, It is an interface unit that controls an interface with each of the color synthesis units 7. The CPU 24 controls the processing of the extension software module unit 20.

  FIG. 8 is a flowchart for explaining the processing of the image processing apparatus according to the second embodiment of the present invention.

  First, in step S131, the language analysis block of the semantic analysis unit 1 performs language analysis on the input page description language. Next, in step S132, it is determined whether or not the above-described clock switching has been completed. If the clock switching has not been completed, step S132 is executed until the clock switching is completed. When the clock switching is thus completed, the process proceeds to step S133, and the input page description language is converted into a parameter setting instruction and an internal processing instruction based on the language analysis in step S131. Next, in step S134, it is determined whether the instruction generated in step S133 can be processed by the pipeline module. If it can be processed, it is processed in step S135. If it is determined that processing cannot be performed by the pipeline module, the process advances to step S137 to determine whether processing by the extended hardware modules 12 to 19 is possible. If processing is possible, the process proceeds to step S138, and processing by the corresponding extended hardware module is performed. On the other hand, if it is determined that the process cannot be performed in step S137, the process proceeds to step S139, and the process by the extended software module is executed. After executing step S135, step S138, or S139 in this way, the process proceeds to step S136 to perform data output processing.

  In parallel with the language analysis processing in step S131 described above, the input page description language is fetched by the PDL prefetch unit 40 in step S141, and an instruction that requires processing in the extended rendering module 11 is input in step S142. It is checked whether it is included in the data, and the result is transmitted to the clock control unit 41. Thus, the clock control unit 41 executes a clock switching process for supplying a clock to the CPU 24 of the extended rendering module 11 that needs to be processed based on the result from the PDL prefetch unit 40. It is determined in step S132 whether or not this switching process has been completed, and the above-described process is executed.

  FIG. 9 is a flowchart for explaining the details of the clock switching process according to the second embodiment.

  First, in step S151, input data prefetch processing is performed. In step S152, the syntax of the prefetched input data is analyzed, and a function necessary for input data processing is searched. Next, in step S153, it is checked whether or not there is a function to be processed by the extended rendering module 11 based on the search result. If there is no need for the extended rendering module 11, a processing end signal is output. The process ends.

  On the other hand, if it is necessary to perform processing in the extended rendering module 11 in step S153, the process proceeds to step S154 to check whether or not there is a corresponding extended hardware module. If there is, the clock is supplied to the extended hardware module in step S155. To finish the process. If it is determined in step S154 that processing by the extended hardware module is not necessary, a clock is supplied to the corresponding interface of the extended software module in step S156.

  FIG. 10 is a diagram illustrating the module configuration of the basic rendering processing unit and the extended rendering processing unit of the image processing apparatus according to the second embodiment.

  In the figure, for example, the extended rendering modules connected to the edge processing unit 3 of the rendering processing unit 2 are “BitmapFont”, “FastBitmapEncoding”, “Bezier”, “DiretSorting”, and “BitmapFont” is the extended hardware module No1. It is understood that “FastBitmapEncoding” is processed by the extended software module interface No1, “Bezier” is processed by the extended hardware module No2, and “DiretSorting” is processed by the extended software module interface No1. Note that “No” assigned to these extended rendering modules is a number assigned to each module.

  The data input to the image processing apparatus according to the second embodiment is data described in a page description language as in the first embodiment, and is a postscript that is a typical language as a page description language. The Bezier curve process at the time of use is executed in the same manner as in the first embodiment.

  Specifically, the PDL prefetch unit 40 fetches PDL data from the address of the designated main memory, analyzes the meaning of the page description language, and when there is an operator that matches “curveto” (FIG. 6), It is determined that the input data includes a Bezier curve, and the determination result is transmitted to the clock control unit 41. Since the extended rendering module corresponding to the Bezier curve is found to be the extended hardware module No. 2 from FIG. 10, the clock control unit 41 supplies the extended hardware module No. 2 with a clock and performs a semantic analysis on the clock supply end signal. Send to part 1.

  The semantic analysis unit 1 interprets the input page description language and generates an instruction for the basic rendering processing unit 2. The commands generated in this way include simple processing such as loop processing and condition determination, numerical calculation, parameter setting, and the like. After the clock switching end signal from the clock control unit 41 is asserted, the generated instruction is output to the rendering processing unit 2. When the generated instruction is parameter setting, the parameter is set in a predetermined table.

  On the other hand, when the generated instruction relates to a rendering process that can be processed by the pipeline module, the process is performed in each pipeline module in the rendering processing unit 2 (step S135). If the generated rendering instruction is an instruction that cannot be processed by each pipeline module and can be processed by the extended hardware module (step S137), all of the extended hardware modules connected to the pipeline module are processed. Broadcast instructions. In this way, each extended hardware module decodes the received rendering command, determines whether the own module needs to be processed, and performs processing when it is determined that the own module needs to be processed (step S138).

  If the generated rendering instruction cannot be processed by each pipeline module and cannot be processed by the extended hardware module, the rendering instruction is supplied to the extended software module interface connected to the pipeline module. As a result, the extended software module processes the rendering command input to the interfaces 21 to 26 using the CPU 24 (step S139).

  For example, when the instruction input to the edge processing unit 3 is Bezier curve processing, the edge processing unit 3 broadcasts the instruction to the extended hardware module. In the second embodiment, the extended hardware module No. 2 is a module that performs Bezier curve processing. For this reason, the extended hardware module No. 2 decodes the received instruction and performs Bezier processing when the data is an instruction related to Bezier. In this case, the other extended hardware modules connected to the edge processing unit 3 are not operated because the clock is not supplied when they are not related to the input data processing. Even when there is another extended hardware module to which a clock is supplied, if the received instruction is decoded and it is determined that the instruction does not need to be processed by the own module, no processing is performed.

  If the command generated by the semantic analysis unit 1 is output processing, the data stored in the output processing unit 8 is output to the output device 9, and printing processing or screen output is performed.

  Note that the present invention can be applied to a system (for example, a copier, a facsimile machine, etc.) composed of a single device even if it is applied to a system composed of a plurality of devices (for example, a host computer, interface device, reader, printer, etc.). May be.

  Another object of the present invention is to supply a storage medium (or recording medium) on which a program code of software for realizing the functions of the above-described embodiments is recorded to a system or apparatus, and to perform computer (or CPU or MPU) of the system or apparatus. ) Is also achieved by reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. A case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing is also included.

  Furthermore, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function is determined based on the instruction of the program code. The case where the CPU of the expansion card or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing is also included.

It is a block diagram which shows an example of the image processing apparatus which concerns on Embodiment 1 of this invention. It is a flowchart explaining the process of the image processing apparatus which concerns on Embodiment 1 of this invention. 4 is a flowchart illustrating details of a clock switching process according to the first embodiment. It is a figure explaining the module structural example of the basic rendering process part 2 of the image processing apparatus which concerns on this Embodiment 1, and an extended software module. It is the figure which represented visually the middle point W (t = 1/2) of the Bezier curve with four control points. It is a figure explaining the instruction | indication of the postscript describing a Bezier curve. It is a block diagram explaining the structure of the image processing apparatus which concerns on Embodiment 2 of this invention. It is a flowchart explaining the process of the image processing apparatus which concerns on Embodiment 2 of this invention. 10 is a flowchart illustrating details of a clock switching process according to the second embodiment. It is a figure explaining the module structure of the basic rendering process part of the image processing apparatus which concerns on this Embodiment 2, and an extended rendering process part.

Claims (2)

An image processing apparatus for inputting page description language data, generating and outputting image data,
An analysis means for analyzing the input page description language data;
Rendering means for rendering the page description language data based on the analysis by the analysis means;
A plurality of extension software modules that execute a part of the rendering function by the rendering means, each of which includes a CPU;
Determining means for determining whether or not the page description language data includes an instruction to be processed by an extended software module;
Based on the determination result by the determination means, a clock signal is supplied to the CPU of the corresponding extension software module among the plurality of extension software modules, and a signal indicating that the clock is supplied to the CPU is transmitted to the analysis means . Control means;
Output processing means for inputting the image data rendered by the rendering means and outputting the image data to an output device, and supplying a signal indicating that rendering by the rendering means is completed to the control means,
When the analysis means receives a signal indicating that a clock is supplied to the CPU from the control means, the rendering means starts rendering by the rendering means,
When the control means receives a signal indicating that the rendering has been completed, the control means stops the supply of a clock to the CPU .   The image processing apparatus according to claim 1, wherein the rendering unit performs rendering processing by supplying predetermined page description language data to a corresponding extended software module.

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