JP2016052089A - Device, method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device, a method, and a program which reduces the scale of an image processing circuit by reducing the consumption of a memory by an image processing parameter.SOLUTION: A device includes: image drawing means for generating an image; and a main memory in which a parameter to be used for processing executed by the image drawing means is preserved. The image drawing means includes: a local memory in which the parameter is preserved; and a local memory control means for controlling the local memory. The local memory control means determines whether or not an idle area for preserving a parameter of a request target exists in the local memory, when the parameter of the request target does not exist in the local memory. When there is no idle area, the local memory control means deletes, among parameters already preserved in the local memory, a parameter having the lowest use frequency, and acquires the parameter of the request target from the main memory to preserve in the local memory.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image processing circuit that processes various images, and more particularly, to an apparatus, a method, and a program for reducing the memory consumption by image processing and reducing the scale of the image processing circuit.

  Conventionally, when a print target image such as a photographic image is output by an image processing apparatus, in order to print the print target image with print color toner or ink that can be output by the image processing apparatus, color matching processing, halftone processing, etc. Various image processing is performed. In these processes, an enormous amount of image processing parameters are used, and therefore, a technique for speeding up the processing by storing the image processing parameters in the internal memory of the image processing circuit is used.

  For example, Patent Document 1 discloses a halftone generation device that generates a halftone image for each pixel of multilevel image data by comparison with a predetermined threshold. In this halftone generation device, an image processing parameter reading unit constituting the image processing circuit reads various image processing parameters from the main memory, and a lattice point data storage unit and a gamma table storage unit which are internal memories of the image processing circuit, Each image processing parameter is stored in a halftone parameter storage unit or the like, and various image processing is executed.

  However, in the halftone generation device disclosed in Patent Document 1, since the image processing circuit reads a large amount of image processing parameters from the main memory and stores them in each internal memory, the amount of memory consumed by the image processing parameters increases. There is a problem that the memory circuit cannot be reduced, and the scale of the entire image processing circuit cannot be reduced.

  The present invention has been made in view of the above-described problems of the prior art, and provides an apparatus, method, and program for reducing the scale of an image processing circuit by reducing the amount of memory consumed by image processing parameters. The purpose is to do.

  The apparatus of the present invention includes a drawing unit that generates an image, and a main memory that stores parameters used for processing executed by the drawing unit. The drawing means includes a local memory for storing parameters and a local memory control means for controlling the local memory. The local memory control means determines whether there is a free area in the local memory where the requested parameter can be stored when the requested parameter does not exist in the local memory. When there is no free space, the local memory control means deletes the least frequently used parameter from the parameters already stored in the local memory, acquires the requested parameter from the main memory, and stores it in the local memory. .

  The present invention can reduce the amount of memory consumed by image processing parameters, and can reduce the scale of an image processing circuit.

The figure which shows the hardware constitutions of the image processing apparatus of this invention. 2 is a diagram showing a functional configuration of a local memory controller 115 provided in the drawing unit 110. FIG. 5 is a flowchart illustrating an embodiment of processing executed by a conversion unit 114 of the drawing unit 110. 5 is a flowchart illustrating an embodiment of processing executed by a local memory controller 115. The figure which shows one Embodiment of the memory area allocation of the local memory 116 with which the drawing part 110 is provided.

  FIG. 1 is a diagram showing a hardware configuration of an image processing apparatus according to the present invention. The image processing apparatus 10 is an apparatus capable of printing various images, and includes a controller board 100, an operation panel 121, and a printer engine 122.

  The controller board 100 is a control device that controls the image processing apparatus 10 and is configured by a semiconductor device such as an LSI. The controller board 100 includes a CPU 101, a main memory 102, a drawing device 103, an operation panel control unit 104, and an engine control unit 105. These devices are communicably connected via a communication bus 106.

  The CPU 101 is a processor that controls processing executed by the controller board 100. The CPU 101 interprets PDL (Page Description Language) provided by an external device such as a PC, and executes a drawing command for instructing printing of the print target image for each pixel data constituting the print target image, and the drawing device 103 executes. Parameters necessary for the processing to be performed are generated, a drawing command is provided to the drawing apparatus 103, and the parameters are stored in the main memory 102. In addition, the CPU 101 provides pixel data of the image to be printed and parameters for each pixel in response to an instruction from the drawing apparatus 103.

  The main memory 102 is a storage device that provides an area where a program executed by the CPU 101 is expanded, and is configured by a memory such as a RAM. In the present embodiment, only the CPU 101 can access the main memory 102. In another embodiment, an LSI having a DMA (Direct Memory Access) function may be provided to access the main memory 102 without using the CPU 101.

  The drawing device 103 is a drawing unit that generates various images, and includes a semiconductor device such as an ASIC. The drawing apparatus 103 includes a drawing unit 110, a bus controller 117, a memory arbiter 118, a CPU interface (I / F) 119, and a communication controller 120.

  The drawing unit 110 is a unit that generates a drawn image and performs various processes. The drawing unit 110 includes a command drawing unit 111, a rotation unit 112, a synthesis unit 113, a conversion unit 114, a local memory controller 115, and a local memory 116.

  The command drawing unit 111 is a unit that generates a drawing image using a drawing command provided by the CPU 101. The command drawing unit 111 stores a drawing image generated using a drawing command in the main memory 102 via the CPU 101.

  The rotation unit 112 is a unit that rotates a drawing image using a rotation processing parameter provided by the CPU 101. The rotation unit 112 acquires pixel data of a drawing image from the main memory 102 via the CPU 101, and rotates the pixel data using a rotation processing parameter. The rotation unit 112 stores the pixel data of the rotated drawing image in the main memory 102 via the CPU 101.

  The synthesizing unit 113 is a unit that synthesizes a drawn image using the synthesis processing parameters provided by the CPU 101. The synthesizing unit 113 acquires pixel data of the drawn image from the main memory 102 via the CPU 101, and synthesizes the pixel data using the synthesis processing parameter. The synthesizing unit 113 stores the pixel data of the synthesized drawing image in the main memory 102 via the CPU 101.

  The conversion unit 114 is a unit that performs various conversion processes on the rendered image using the conversion process parameters provided by the CPU 101. The processing executed by the conversion unit 114 will be described in detail with reference to FIG.

  In the embodiment shown in FIG. 1, the drawing unit 110 includes four types of image processing means (command drawing unit 111, rotation unit 112, composition unit 113, and conversion unit 114), but the drawing unit 110 performs other image processing. Means may be provided.

  The local memory controller 115 is means for controlling the local memory 116. In response to a request from image processing means (hereinafter referred to as “module”) included in the drawing unit 110, the local memory controller 115 receives parameters used by these modules, management information of the parameters, and pixel data of the drawn image. Save to local memory 116.

  The local memory controller 115 dynamically secures an area of the local memory 116 when storing parameters. The local memory controller 115 can dynamically secure an area of the local memory 116 when storing the parameters. As a result, the local memory 116 can be used efficiently, and the consumption of the local memory 116 can be reduced.

  Further, the local memory controller 115 can secure an area of the local memory 116 for each of a plurality of modules provided in the drawing unit 110. A module that has a faster image processing speed than other modules can be prioritized over other modules by securing a larger memory area than the other modules. The function of the local memory controller 115 will be described in detail with reference to FIG.

  The local memory 116 is a storage device that stores parameters used by other modules of the drawing unit 110, management information of the parameters, and pixel data to be processed. The local memory 116 is composed of a single memory, and stores parameters required by a plurality of modules of the drawing unit 110, respectively. In general, a memory (cache memory or the like) that is faster than the main memory 102 is used as the local memory 116.

  As shown in FIG. 5, the local memory 116 has a management information storage area for storing parameter management information, a parameter storage area for storing parameters, and an area for storing pixel data to be processed (not shown). ).

  In the embodiment shown in FIG. 5, as parameter management information, a module number that is module identification information, a process number that is identification information of processing executed by the module, and a start address that indicates the start address of the parameter storage destination And the parameter data size are stored in the management information storage area. The parameters used by the module of the drawing unit 110 are stored in the parameter storage area indicated by the start address which is parameter management information.

  The local memory 116 preferentially stores parameters that are frequently used. The local memory 116 stores parameter management information so that the local memory controller 115 can determine the parameter usage frequency. Specifically, in the present embodiment, the management information storage area has a LIFO format stack structure, and the most recently used management information of the latest parameter is the highest-level memory starting from the top address of the management information storage area Saved in the area.

  The capacity of the local memory 116 can be determined by the designer according to the number of parameters used by the drawing unit 110 and the data size thereof. The capacity of the local memory 116 is preferably smaller than the data size of all parameters used by the drawing unit 110.

  The bus controller 117 is means for controlling data communication via the communication bus 106. The memory arbiter 118 is means for controlling data communication between the drawing unit 110 and other modules of the drawing apparatus 103. The CPU interface 119 is means for controlling data communication with the CPU 101. The communication controller 120 is means for controlling data communication between the image processing apparatus 10 and an external device.

  The operation panel control unit 104 is means for controlling the operation panel 121 that is a device that can accept a user instruction to the image processing apparatus 10. The engine control unit 105 is a unit that controls the printer engine 122 that prints an image to be printed on a print medium.

  FIG. 2 is a diagram illustrating a functional configuration of the local memory controller 115. The local memory controller 115 includes a parameter presence / absence determination unit 200, a free space determination unit 201, a memory control unit 202, a management information generation unit 203, a parameter acquisition unit 204, and a parameter provision unit 205.

  The parameter presence / absence judgment unit 200 is a means for judging whether or not the requested parameter is stored in the local memory 116. The free space determination unit 201 is a means for determining whether or not there is a free space in the local memory 116 that can store the requested parameter. The memory control unit 202 is means for controlling the local memory 116 to store, delete, and replace data.

  The management information generation unit 203 is a unit that generates management information of the parameter to be requested. The management information generation unit 203 uses the identification information of the module provided by the request source, the identification information of the process executed by the module, and the start of the free space in the parameter storage area of the local memory 116 as the management information of the request target parameter An address and a predetermined data size are generated. The predetermined data size is the size of the request target parameter, and can be a predetermined data size that can store the request target parameter. The predetermined data size may be the data size indicated by the request source.

  The parameter acquisition unit 204 is a means for acquiring a request target parameter stored in the main memory 102. The parameter providing unit 205 is a means for providing the requested parameter to the requesting module.

  FIG. 3 is a flowchart illustrating an embodiment of processing executed by the conversion unit 114 of the drawing unit 110. Hereinafter, with reference to FIG. 3, a process in which the conversion unit 114 performs various conversion processes (color space conversion process, gamma conversion process, and gradation conversion process) on the drawn image will be described.

  The processing shown in FIG. 3 starts from step S300. In step S301, the conversion unit 114 instructs the CPU 101 to transfer pixel data of a drawing image from the main memory 102 to the local memory 116, and draws the drawing on the local memory 116. Save the pixel data of the image.

  In step S302, the conversion unit 114 requests the local memory controller 115 for color space conversion processing parameters used for the color space conversion processing of the drawn image. In step S <b> 303, the conversion unit 114 performs color space conversion processing on the pixel data of the drawn image using the color space conversion processing parameters provided by the local memory controller 115.

  In step S <b> 304, the conversion unit 114 requests the local memory controller 115 for a gamma processing parameter used for gamma processing of the drawn image. In step S305, the conversion unit 114 performs gamma processing on the pixel data subjected to the color conversion processing in step S303, using the gamma processing parameters provided by the local memory controller 115.

  In step S306, the conversion unit 114 requests the local memory controller 115 for gradation conversion processing parameters used for the gradation conversion processing of the drawn image. In step S307, the conversion unit 114 performs gradation conversion processing on the pixel data subjected to gamma processing in step S305, using the gradation conversion processing parameters provided by the local memory controller 115.

  In step S <b> 308, the conversion unit 114 instructs the local memory controller 115 to transfer the pixel data of the drawn image subjected to the gradation conversion process to the main memory 102. In step S309, the conversion unit 114 determines whether or not conversion processing has been executed for all the pixels constituting the drawing image to be processed. If the conversion process has not been executed for all the pixels (no), the process returns to step S301, and the above-described process is executed for the pixel data of the drawing image to be processed next. On the other hand, if the conversion process has been completed for all pixels (yes), the process ends in step S310.

  FIG. 4 is a flowchart illustrating an embodiment of processing executed by the local memory controller 115. Hereinafter, with reference to FIG. 4, processing executed by the local memory controller 115 when a parameter is requested from another module of the drawing unit 110 will be described.

  The process shown in FIG. 4 starts when a parameter is requested from the module of the drawing unit 110 in step S400. In step S <b> 401, the parameter presence / absence determining unit 200 of the local memory controller 115 determines whether or not the request target parameter exists in the local memory 116.

  In this embodiment, the request source module transmits the module identification information and the identification information of the process executed by the module to the local memory controller 115. The parameter presence / absence determination unit 200 determines whether the identification information exists in the management information storage area of the local memory 116. If these pieces of identification information exist in the management information storage area of the local memory 116, the parameter presence / absence determination unit 200 determines that the requested parameter exists in the local memory 116.

  In the present embodiment, the parameter management information is stored in the parameter storage area in the order of the frequency of use of the parameter, so the parameter presence / absence determination unit 200 can search in order from the management information of the parameter with the highest use frequency. Can be efficiently determined.

  If the requested parameter is in the local memory 116 (yes), the process branches to step S402. In step S <b> 402, the memory control unit 202 moves the management information of the request target parameter to the head of the management information storage area of the local memory 116.

  On the other hand, if it is determined in step S401 that the requested parameter is not in the local memory 116 (no), the process branches to step S403. In step S403, the free space determination unit 201 determines whether there is a free space in the local memory 116 that can store the requested parameter and management information of the parameter. If there is an empty area (yes), the process branches to step S406. On the other hand, if there is no free space (no), the process branches to step S404.

  In step S <b> 404, the memory control unit 202 deletes the parameter that is least frequently used from the local memory 116. As a result, frequently used parameters can be preferentially held in the local memory 116, so that the number of times that the request target parameter is acquired from the main memory 102 can be reduced, resulting from the acquisition of the request target parameter. A reduction in processing speed can be suppressed.

  In the present embodiment, parameter management information is stored in the parameter storage area in the order in which the parameters are used. Therefore, the memory control unit 202 is identified by the management information stored at the end of the management information storage area. Delete the parameter from the parameter storage area. In another embodiment, frequency information indicating the usage frequency of a parameter is stored as management information of the parameter, and the memory control unit 202 specifies the parameter with the lowest usage frequency by using the frequency information. Also good.

  In step S <b> 405, the memory control unit 202 deletes the management information of the parameter with the lowest usage frequency from the local memory 116. In this embodiment, the management information stored at the end of the management information storage area is deleted from the parameter management information.

  In step S <b> 406, the management information generation unit 203 creates management information for the request target parameter, and the memory control unit 202 stores the management information at the head of the management information storage area of the local memory 116. In step S407, the parameter acquisition unit 204 requests the CPU 101 for the request target parameter stored in the main memory 102, and the memory control unit 202 displays the parameter provided by the CPU 101 in the local memory indicated by the management information of the parameter. 116 is stored in the parameter storage area 116.

  In the present embodiment, the parameter acquisition unit 204 provides the CPU 101 with the identification information of the module provided by the request source module and the identification information of the process executed by the module as the identification information of the request target parameter. The CPU 101 uses these identification information to specify a request target parameter from parameters stored in the main memory 102.

  In step S408, the parameter providing unit 205 acquires the requested parameter from the local memory 116 and provides it to the requesting module, and the process ends in step S409.

  As described above, various parameters required by a plurality of modules of the drawing unit 110 are stored in the local memory 116, and the use frequency of the parameters is compared between the plurality of modules, and a parameter with a low use frequency is stored. delete. For this reason, compared to the embodiment in which a local memory is installed for each module and a low-use parameter is deleted for each local memory, a low-use parameter can be effectively reduced, and the circuit scale can be reduced. Can be

  Although the present embodiment has been described so far, the present invention is not limited to the above-described embodiment, and the constituent elements of the present embodiment are changed or deleted, or other constituent elements are included in the constituent elements of the present embodiment. Changes can be made within the range that can be conceived by those skilled in the art, such as adding elements. Any aspect is included in the scope of the present invention as long as the effects of the present invention are exhibited.

  DESCRIPTION OF SYMBOLS 10 ... Image processing apparatus, 100 ... Controller board, 101 ... CPU, 102 ... Main memory, 103 ... Drawing apparatus, 104 ... Operation panel, 105 ... Engine control part, 106 ... Communication bus, 121 ... Operation panel, 122 ... Printer engine

Patent No. 5146216

Claims (10)

An apparatus comprising drawing means for generating an image and a main memory in which parameters used by the drawing means are stored,
The drawing means includes
Local memory in which the parameters are stored;
A local memory control means for controlling the local memory,
The local memory control means includes
Free area determination means for determining whether or not there is a free area in the local memory where the requested parameter can be stored when the request target parameter does not exist in the local memory;
When there is no free space in the local memory, a deletion unit that deletes a parameter that is least frequently used among parameters already stored in the local memory;
Obtaining means for obtaining the requested parameter from the main memory;
A storage unit configured to store the request target parameter acquired by the acquisition unit in the local memory. The local memory control means includes
The apparatus according to claim 1, further comprising a parameter presence / absence determining unit configured to determine whether or not the parameter exists in the local memory when the parameter is requested. The local memory has a parameter area in which the parameters are stored, and a management information storage area in which management information of the parameters is stored.
The local memory control means includes
3. The apparatus according to claim 1, wherein the parameter area and the management information storage area are dynamically secured when the parameter is stored. The local memory control means includes
4. The apparatus according to claim 3, wherein the parameter area and the management information storage area are secured for each of a plurality of image processing means provided in the drawing means.   The deletion unit deletes a parameter that is stored in the local memory and is least frequently used among parameters used by a plurality of image processing units included in the drawing unit. 5. The apparatus according to any one of 4 above. A method executed by a drawing device that generates an image,
The drawing device includes a local memory in which parameters used by the drawing device are stored;
In the method, the drawing apparatus comprises:
Receiving a request for said parameter;
Determining whether or not there is a free area in the local memory where the requested parameter can be stored when the requested parameter does not exist in the local memory; and
If there is no free space in the local memory, deleting the least frequently used parameter among the parameters already stored in the local memory;
Obtaining the parameter to be requested from the outside;
Storing the obtained parameter to be requested in the local memory. In the method, the drawing apparatus comprises:
The method according to claim 6, further comprising the step of determining whether a requested parameter exists in the local memory when a parameter used for processing of the drawing apparatus is requested. In the method, the drawing apparatus comprises:
The method according to claim 6, further comprising the step of dynamically securing a parameter area in which the parameter is stored and a management information storage area in which the management information of the parameter is stored when the parameter is saved. . The securing step includes
The method according to claim 8, further comprising the step of securing the parameter area and the management information storage area for each of a plurality of image processing means provided in the drawing apparatus.   A device-readable program that causes a device that processes an image to execute the method according to claim 6.