JP2010099973A - Image forming apparatus and image forming program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that, when a drawn graphic for preparing a mask image is held by a display list (DL) which is an intermediate language in the drawing processing for analyzing a page description language and preparing drawn data in an image forming apparatus, the size of the DL is so large as to generate the shortage of resources such as memory depending on the drawn graphic. <P>SOLUTION: In the image forming apparatus, the shortage of resources is eliminated by comparing the size of the DL drawn on a mask plane with the size of the bitmap mask plane for drawing the same DL and holding the data according to the format having a smaller size. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for suppressing memory consumption in a process of converting a page description language into print data through an intermediate language in an image forming apparatus.

  In the drawing process when interpreting and printing the page description language, the figure clipping process may be executed. In that case, it is necessary to develop the image for creating a mask image into a buffer different from the output buffer. The graphic data forming the mask image is composed of DL (display list) which is an intermediate language obtained by converting the page description language. The DL that forms the mask image needs to be held on the memory until mask data is no longer needed. This DL is not freed even by a pre-description executed when the memory is insufficient unlike the DL constituting the output page image.

  Further, depending on the graphic data, the memory amount required for holding in DL may be larger than the memory amount in the bitmap of the image data. Therefore, the memory for the mask image DL is consumed, memory resources are insufficient, and it may be difficult to continue the rendering process.

  As a prior art, in order to eliminate the blur around the boundary caused by enlarging the image information plane reduced at the time of encoding, the input image is separated from the background plane image composed of non-image parts by the image separation unit. The pattern is divided into three planes: a pattern plane image and a mask plane image indicating the location of the pattern portion. The pattern portion is encoded by reduction at a low resolution, and the boundary portion is encoded without sacrificing the resolution. There is a method of performing (see Patent Document 1).

However, this method is intended to eliminate the blur around the boundary, and does not solve the shortage of memory resources when creating a mask image.
Japanese Patent Laid-Open No. 2003-87558

  The problem to be solved is that in the image forming apparatus and the image forming program, when the page description language is converted to the print data through the intermediate language, the size of the intermediate language data increases due to complicated drawing figures, and the memory resource Is a point of consuming.

  The image forming apparatus according to the present invention includes a data analysis processing unit that analyzes print data described in a page description language and converts the print data into an intermediate language, and counts the data size of the intermediate language data converted by the data analysis processing unit. An intermediate language size counting unit, a bitmap size counting unit for counting the data size of the bitmap data of the intermediate language data, a data size of the intermediate language data counted by the intermediate language size counting unit, and the bitmap A data size determining unit that determines the size of the bitmap data counted by the size counting unit; and if the data size determining unit determines that the data size of the intermediate language data is small, the intermediate language The data is retained as is, and the bitmap data size is judged to be small. In this case, the intermediate language data is converted into bitmap data, and a small size data selection unit that holds the data, and the intermediate language data and bitmap data selected by the small size data selection unit are developed in a rendering buffer. And a rendering processing unit.

  Further, the intermediate language size counting unit and the bitmap size counting unit of the image forming apparatus of the present invention count the data size for each mask plane, and the data size determining unit counts the data size for each mask plane. It is good also as a characteristic to judge.

  Further, the data size of the bitmap data counted by the bitmap size counting unit of the image forming apparatus of the present invention is based on the width, height, and color depth of the circumscribed rectangle of the mask plane that includes the mask plane. It may be characterized by being fixed.

  The image forming program of the present invention includes a data analysis processing function for analyzing print data described in a page description language on a computer and converting the print data into an intermediate language, and a data size of the intermediate language data converted by the data analysis processing unit An intermediate language size counting function, a bitmap size counting function for counting the data size of the bitmap data of the intermediate language data, a data size of the intermediate language data counted by the intermediate language size counting unit, A data size determination function that determines the size of the data size of the bitmap data counted by the bitmap size counting unit, and when the data size determination unit determines that the data size of the intermediate language data is small, Data is retained as intermediate language data, and bitmap data is A small size data selection function for converting the intermediate language data into bitmap data and holding the data, and the intermediate language data and bitmap selected by the small size data selection unit A rendering processing function for developing data in a rendering buffer is realized.

  The image forming apparatus according to the present invention includes a data analysis processing unit that analyzes print data described in a page description language and converts the print data into an intermediate language, and counts the data size of the intermediate language data converted by the data analysis processing unit. An intermediate language size counting unit, a bitmap size counting unit for counting the data size of the bitmap data of the intermediate language data, a data size of the intermediate language data counted by the intermediate language size counting unit, and the bitmap A data size determining unit that determines the size of the bitmap data counted by the size counting unit; and if the data size determining unit determines that the data size of the intermediate language data is small, the intermediate language The data is retained as is, and the bitmap data size is judged to be small. In this case, the intermediate language data is converted into bitmap data, and a small size data selection unit that holds the data, and the intermediate language data and bitmap data selected by the small size data selection unit are developed in a rendering buffer. And a rendering processing unit.

  For this reason, it is possible to prevent the data size of the intermediate language from increasing due to complex drawing data, consuming memory resources and stopping the drawing data processing.

  Further, the intermediate language size counting unit and the bitmap size counting unit of the image forming apparatus of the present invention count the data size for each mask plane, and the data size determining unit counts the data size for each mask plane. It is good also as a characteristic to judge.

  For this reason, it is possible to control the suppression of fine data size consumption in units of mask planes.

  Further, the data size of the bitmap data counted by the bitmap size counting unit of the image forming apparatus of the present invention is based on the width, height, and color depth of the circumscribed rectangle of the mask plane that includes the mask plane. It may be characterized by being fixed.

  For this reason, the calculation of the data size of the bitmap only needs to obtain a simple circumscribed rectangle shape, so that the processing speed is improved.

  The image forming program of the present invention includes a data analysis processing function for analyzing print data described in a page description language on a computer and converting the print data into an intermediate language, and a data size of the intermediate language data converted by the data analysis processing unit An intermediate language size counting function, a bitmap size counting function for counting the data size of the bitmap data of the intermediate language data, a data size of the intermediate language data counted by the intermediate language size counting unit, A data size determination function that determines the size of the data size of the bitmap data counted by the bitmap size counting unit, and when the data size determination unit determines that the data size of the intermediate language data is small, Data is retained as intermediate language data, and bitmap data is A small size data selection function for converting the intermediate language data into bitmap data and holding the data, and the intermediate language data and bitmap selected by the small size data selection unit A rendering processing function for developing data in a rendering buffer is realized.

  For this reason, it is possible to prevent the data size of the intermediate language from increasing due to complex drawing data, consuming memory resources and stopping the drawing data processing.

  In the image forming apparatus and the image forming program, there is a problem that memory resources are consumed due to an increase in the intermediate language data size converted from the page description language due to complicated drawing figures, and drawing processing cannot be performed. In order to solve the problem, when the data size becomes smaller when the intermediate language data is converted into the bitmap data, the problem is solved by performing the bitmap processing and holding the bitmap data.

[Drawing figure on mask plane, rendering]
FIG. 1A shows a drawing figure described in the print data. This drawing figure is placed on the mask plane shown in FIG. The mask plane is mask data for drawing having 0/1 information (0: not drawing / 1: drawing) indicating which pixel is drawn or not drawn in rendering. The mask plane exists at the width and height of the rendering buffer. A mask plane buffer is secured in advance, and is additionally secured when masking at a higher level. The contents of the image to be drawn on the mask plane are registered in a dedicated management structure as a display list and linked to a display list indicating a figure of the rendering contents of the corresponding band.

  FIG. 1C illustrates a rendering buffer that is finally rendered. On the rendering buffer, a drawing figure is drawn within a frame designated by a mask plane.

[DL management structure on rendering buffer and mask plane]
FIG. 2A shows a data structure when page data in the prior art is converted into a display list which is an intermediate language. Shown on the left is the state in which the page data is divided into bandwidths. The right side shows a display list management structure in which display lists are arranged on the link list for each band.

  FIG. 2B similarly shows a display list management structure on a mask plane in the prior art. Similarly to FIG. 2A, the left side shows a state where pages are divided for each bandwidth. On the right side, a display list management structure in which a display list in which a drawing figure to be drawn on a mask plane is arranged for each band is arranged on the link list is shown.

  As described above, conventionally, the page description language is once converted into an intermediate language display list for each page, and then the display list is converted into a bitmap by performing rasterization processing.

[Convert display list to mask image]
In the image forming apparatus according to the present invention, the total size of the display list (DL), which is an intermediate language for rendering on the mask plane, in the process of rendering the page description language, which is print data, in band units by the printer is the buffer size of the mask plane. When it becomes larger, it is once rasterized (bitmap development into a mask image). In some cases, rasterized data may be compressed. The display list is switched to hold a mask image instead of holding a drawing figure. FIG. 3 shows a state where the DL management structure drawn on the mask plane is replaced with a mask image (a compressed mask image when data is compressed). The data of the DL management structure replaced with the mask image is erased from the memory.

  As shown in FIG. 3, by replacing the DL management structure as an image of the mask plane that exists for each band and maintaining it, the display list for drawing on the mask plane increases too much, and those data are stored. It is possible to avoid the memory being pressed without being released.

[Constitution]
FIG. 4 is a functional block diagram of the image forming apparatus 10 according to the embodiment of the present invention.

  The image forming apparatus 10 includes functional units such as a communication interface 11, a data receiving unit 12, a data analyzing unit 13, a drawing data processing unit 14, a mask plane rasterizing unit 15, a rendering processing unit 16, an output unit 17, and a memory management unit 18. Have.

  The mask plane rasterizing unit 15 further includes functional units such as a display list size counting unit 21 (intermediate language size counting unit), a bitmap size counting unit 23, a data size determination unit 25, and a small size data selection unit 27.

  The communication interface 11 is a functional unit that communicates with a host computer or the like. The print data described in the page description language is transferred to the data receiving unit 12 via the communication interface 11.

  The data receiving unit 12 is a functional unit that receives data via the communication interface 11.

  The data analysis unit 13 (data analysis processing unit) is a functional unit that analyzes the sent print data. The print data is described in a page description language, and the page description language is analyzed.

  The drawing data processing unit 14 (data analysis processing unit) converts the page description language into a display list (DL) that is an intermediate language based on the analysis by the data analysis unit 13.

  The data analysis unit 13 and the drawing data processing unit 14 work together as a data analysis processing unit, analyze print data described in a page description language, and convert it into an intermediate language.

  When the data analysis unit 13 analyzes the page description language and the drawing data processing unit 14 creates the display list, the generated display list is added to the link list of the display list for each band. For a figure to be drawn, the display list is stored in the DL management structure that is drawn on the mask plane at the same time. The display list for drawing on the mask plane exists in the memory until rendering becomes unnecessary after rendering. When the total size of the display list drawn on the mask plane becomes larger than the mask plane size, a mask plane buffer for the band is secured and the display list is expanded. At this time, the data may be compressed.

  The mask plane rasterizing unit 15 is a functional unit that counts the size of the drawing figure described in the display list when it is bitmapped on the mask plane, and selects and holds the smaller one with the display list. is there. Each functional unit in the mask plane rasterizing unit 15 will be described in more detail below.

  The display list size counting unit 21 (intermediate language size counting unit) counts the data size of the display list which is intermediate language data converted from the page description language by the drawing data processing unit 14. The data size is counted for each mask plane unit.

  The bitmap size counting unit 23 counts the size of the mask plane buffer when bitmapped for each mask plane unit of the display list. At the time of counting, the data is cut into a circumscribed rectangular shape including a mask plane-like drawing figure. For this reason, the count of the size when bitmapped can be easily obtained from the width, height and color depth of the circumscribed rectangle.

  The data size determining unit 25 determines the size of the data size counted by the display list size counting unit 21 and the bitmap size counting unit 23.

  If the data size determination unit 25 determines that the data size of the display list is small, the small size data selection unit 27 retains the data as intermediate language data, and if the data size of the bitmap data is small If determined, the display list data is converted into bitmap data and the data is held. When converting to bitmap data, the rendering processing unit 16 may perform the conversion.

  The rendering processing unit 16 is a functional unit that performs rendering processing that performs bitmap expansion on the rendering buffer for the display list and bitmap data that are intermediate language data selected by the small size data selection unit 27. This is a functional unit that performs processing to create a bitmap in a video random access memory (VRAM) from the display list created by the drawing data processing unit 14. When rendering is performed by the rendering processing unit 16, the small-size data selection unit 27 selects the already-mapped bitmap data and stores it in the mask plane buffer without being conscious of whether it has been expanded halfway. Just expand the designated display list.

  The output unit 17 is a functional unit that has a print engine and actually prints on a recording medium (such as paper or OHP).

  The memory management unit 18 is a functional unit that manages the memory of the system, and manages the use of the main memory used by each functional unit described above. When the memory resource is insufficient, the function is notified and the operation is stopped.

[flowchart]
The operation flow will be described with reference to the flowchart of FIG.

  S201: The data receiving unit 12 receives print data described in a page description language.

  S202: The loop is repeated for the received print data until reaching the end of the job and the end of the file.

  S203: The data analysis unit 13 analyzes the page description language, and the drawing data processing unit 14 converts it into a display list.

  S204: The drawing data processing unit 14 determines whether the figure is to be drawn on the mask plane. When drawing on the mask plane, the operation proceeds to S205. Otherwise, the operation moves to the loop end.

  S205: The display list size counting unit 21 counts the size of the display list for the graphic drawn on the mask plane. In addition, the bitmap size counting unit 23 counts the mask plane buffer size by a method of cutting a figure to be drawn on the mask plane into a circumscribed rectangle including the mask plane.

  S206: When it is determined in S204 that the figure is to be drawn on the mask plane, the data size determining unit 25 uses the display list management structure for drawing on the mask plane counted in S205, and the display list size of the corresponding band is the same. It is determined whether or not the mask plane buffer size counted in S205 is exceeded. If the size of the display list is larger, the operation proceeds to S207. Otherwise, move to the end of the loop.

  Here, an example in which the size of the display list is larger than the buffer size of the mask plane is shown in FIG. When a figure with multiple overlapping circles of different sizes is represented in the display list, the circle is divided into multiple trapezoids and each trapezoid is listed as a single display list. As a result, the size becomes larger, and as a result, it becomes smaller to hold the bitmapped data with the size of the mask plane buffer.

  S207: Since the size of the display list is larger than the size of the mask plane buffer, the small size data selection unit 27 selects the bitmap data as the small size data, and the rendering processing unit 16 secures the mask plane buffer on the memory. The display list is expanded into bitmap data on the mask plane buffer.

  At the stage where the above flowchart operation is completed, the bands held in the display list format and the bands that have already been developed in the bitmap are mixed depending on the data size (depending on the data size conditions, all of them may be display lists or bitmaps). Possible).

  After the above flowchart operation, the rendering processing unit 16 performs rendering processing for developing the bitmap on the data on the display list and the mask plane buffer in the rendering buffer, generates drawing data, and outputs the drawing data to the output unit 17. Pass to print.

  About the operation | movement of said flowchart and subsequent rendering operation | movement, it is also possible to perform parallel processing. The rendering operation for each band that has been subjected to the flowchart processing may be performed in parallel while the flowchart operation for the next band is being performed.

  Through the series of operations described above, when the image forming apparatus 10 converts the page description language into a display list that is an intermediate language, performs rendering processing, converts the display list into bitmap data, and develops the display list size and its image development. By comparing the sizes of the (bitmap expanded) data and retaining the smaller data size, consumption of memory resources can be suppressed.

[Effect of Example]
The image forming apparatus according to the embodiment of the present invention enables the following.

  Since the display list to be drawn on the mask plane is not released even at the time of pre-description, for example, when the size of the display list is larger than the size of the mask plane buffer as shown in a typical example of FIG. The display list is image-expanded in the mask plane buffer, and the display list size to be drawn on the mask plane is increased, and the memory for rendering can be prevented from being compressed, and the memory efficient rendering system. Can be realized.

It is explanatory drawing of a drawing figure, a mask plane, and a rendering buffer. It is a structural diagram of the DL management structure in the prior art. It is explanatory drawing of the DL management structure and image buffer in this invention Example. 1 is a functional block diagram of an image forming apparatus according to an embodiment of the present invention. 3 is a flowchart of the image forming apparatus according to the embodiment of the present invention. It is an example of a drawing figure in the case where the size becomes larger than that represented by a bitmap image when represented by a display list.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Communication interface 12 Data receiving part 13 Data analysis part (data analysis processing part)
14 Drawing data processing unit (data analysis processing unit)
DESCRIPTION OF SYMBOLS 15 Mask plane rasterization part 16 Rendering process part 17 Output part 18 Memory management part 21 Display list size counting part (intermediate language size counting part)
23 Bitmap size counting unit 25 Data size judging unit 27 Small size data selecting unit

Claims (4)

A data analysis processing unit that analyzes the print data described in the page description language and converts it into an intermediate language;
An intermediate language size counting unit that counts the data size of the intermediate language data converted by the data analysis processing unit;
A bitmap size counter for counting the data size of the bitmap data of the intermediate language data;
A data size determining unit that determines the size of the data size of the intermediate language data counted by the intermediate language size counting unit and the data size of the bitmap data counted by the bitmap size counting unit;
When the data size determination unit determines that the data size of the intermediate language data is small, the data is held as the intermediate language data, and when the data size of the bitmap data is determined to be small, A small-size data selection unit that converts intermediate language data into bitmap data and holds the data;
An image forming apparatus comprising: a rendering processing unit that develops intermediate language data and bitmap data selected by the small size data selection unit in a rendering buffer. The image forming apparatus according to claim 1,
The intermediate language size counting unit and the bitmap size counting unit count the data size for each mask plane,
The image forming apparatus, wherein the data size determining unit counts and determines a data size for each mask plane. The image forming apparatus according to claim 1, wherein:
The data size of the bitmap data counted by the bitmap size counting unit is determined based on a width, height, and color depth of a circumscribed rectangle of the mask plane that includes the mask plane. . A data analysis processing function that analyzes print data written in a page description language on a computer and converts it into an intermediate language;
An intermediate language size counting function for counting the data size of the intermediate language data converted by the data analysis processing unit;
A bitmap size counting function for counting the data size of the bitmap data of the intermediate language data;
A data size determination function for determining the size of the data size of the intermediate language data counted by the intermediate language size counting unit and the data size of the bitmap data counted by the bitmap size counting unit;
When the data size determination unit determines that the data size of the intermediate language data is small, the data is held as the intermediate language data, and when the data size of the bitmap data is determined to be small, A small-size data selection function that converts intermediate language data into bitmap data and holds the data;
An image forming program for realizing a rendering processing function for expanding intermediate language data and bitmap data selected by the small size data selection unit in a rendering buffer.

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