Data processing apparatus and image forming apparatus

Abstract

To shorten time required for rasterizing a character classified into a composite glyph and to improve quality of the character.SOLUTION: A rasterizing unit 113 generates first raster data using a character to be drawn and stores the first raster data in a component storage area 210 when the character to be drawn in a text document has a common component and when the first raster data is not stored in the component storage area 210, and generates second raster data indicating a non-common component in the character to be drawn and generates a font cache indicating the character to be drawn by combining the first raster data and the second raster data and stores the font cache in a font cache storage area 211 when the first raster data is stored in the component storage area 210.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a data processing device and an image forming device, and more particularly to a technique for performing font rasterization for characters classified as composite glyphs. [Background technology]

[0002] Various techniques related to character drawing processing are known. For example, Patent Document 1 discloses a technique for generating a set of two-dimensional distance fields using a set of elements and rendering a region of a composite glyph using the set of two-dimensional distance fields. Patent Document 2 discloses a technique for finding a set of pixels associated with a region of the two-dimensional distance field, specifying a set of components for each pixel, and calculating an anti-aliasing strength for each component of each pixel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 7,006,108 [Patent Document 2] U.S. Patent No. 7,002,598 Summary of the Invention [Problem to be solved by the invention]

[0004] Languages ​​such as Chinese, Japanese, or Korean contain many characters that are classified as composite glyphs, each containing two or more components, unlike alphabets. When a user prints a large volume of text documents written in languages ​​such as Chinese, Japanese, or Korean, the printing speed decreases due to the load placed on the font rasterization process for the characters, compared to when printing a large volume of text documents written in a single glyph, such as the alphabet.

[0005] The techniques disclosed in Patent Documents 1 and 2 are mainly related to rendering or anti-aliasing, and therefore cannot solve the above problem.

[0006] The present invention has been made in view of the above circumstances, and has as its object to reduce the time required to rasterize characters classified as composite glyphs and to improve the quality of the characters. [Means for solving the problem]

[0007] A data processing device according to one aspect of the present invention includes a memory unit including a component storage area and a font cache storage area; and a rasterization unit that, when a character to be drawn in a text document has a common component shared by multiple composite glyphs and first raster data indicating the common component is not stored in the component storage area, generates first raster data using the character to be drawn and stores it in the component storage area; and, when the first raster data is stored in the component storage area, generates second raster data indicating a non-common component in the character to be drawn, combines the first raster data with the second raster data to generate a font cache indicating the character to be drawn, and stores it in the font cache storage area. [Effects of the Invention]

[0008] According to the present invention, when generating a font cache representing characters with common components, the previously generated first raster data is reused, eliminating the need to rasterize the common components again. As a result, the time required to rasterize characters classified as composite glyphs can be reduced compared to generating first raster data each time. Furthermore, consistency in the shapes of the common components can be achieved, improving the quality of the characters. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a front cross-sectional view showing the structure of the image forming apparatus. [Figure 2] FIG. 1 is a block diagram showing a configuration of an image forming apparatus. [Figure 3] FIG. 10 is a diagram illustrating an example of information registered in a reference table. [Figure 4] FIG. 10 is a diagram illustrating another example of information registered in the reference table. [Figure 5] 10 is a flowchart illustrating a font rasterization process. [Figure 6] 10 is a flowchart showing a first raster data storage process. [Figure 7] FIG. 10 illustrates an example of a method for extracting common components. [Figure 8] FIG. 10 is a diagram showing how first raster data is stored. [Figure 9] FIG. 10 is a diagram showing how the coordinates of a start point are registered. [Figure 10] FIG. 10 is a diagram illustrating how a font cache is generated. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A data processing apparatus and an image forming apparatus according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0011] [Configuration of image forming apparatus 1] Fig. 1 is a front cross-sectional view showing the structure of image forming apparatus 1. Fig. 2 is a block diagram showing the configuration of image forming apparatus 1. Referring to Fig. 1, image forming apparatus 1 is a multifunction peripheral having multiple functions such as a copy function, a transmission function, a printer function, and a facsimile function.

[0012] The housing of the image forming apparatus 1 houses an image reading unit 11, an image forming unit 12, a fixing unit 13, a paper feeding unit 14, and the like.

[0013] The image reading unit 11 reads an image of a document by a moving document method or a fixed document method, and generates image data.

[0014] The image forming unit 12 includes a photosensitive drum, a charging device, an exposure device, a developing device, and a transfer device. The image forming unit 12 forms an image made of a toner image on a sheet P conveyed along a conveying path T based on image data.

[0015] The fixing unit 13 applies heat and pressure to the paper P on which the toner image has been formed by the image forming unit 12, thereby fixing the toner image to the paper P. The paper P on which the toner image has been fixed is discharged onto a discharge tray.

[0016] The paper feed unit 14 includes a manual feed tray and multiple paper feed cassettes. The paper feed unit 14 uses a pickup roller to pull out paper P stored in one of the multiple paper feed cassettes or paper placed on the manual feed tray one by one, and feeds the paper to the transport path T.

[0017] 2, the image forming apparatus 1 includes a control unit 100. The control unit 100 includes a processor, a RAM 200 (Random Access Memory), and a ROM (Read Only Memory). The processor is, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or an ASIC (Application Specific Integrated Circuit). The control unit 100 functions as a data processing device in the claims.

[0018] The control unit 100 functions as a control unit 110, a PDL interpretation unit 111, a font management unit 112, a rasterization unit 113, a rendering unit 114, and a job management unit 115 by the processor executing various computer programs stored in the built-in ROM or HDD (Hard Disk Drive) 18. The control unit 110 performs overall control of the image forming apparatus 1.

[0019] In this embodiment, a PDL (Page Description Language) interpretation unit 111 interprets PDL data, and if the PDL data includes a text document, requests a font management unit 112 and a rasterization unit 113 to start executing the font rasterization process according to this embodiment.

[0020] Here, a text document refers to a document file that does not include graphics or photographs (that is, is composed of text). The font rasterization process according to this embodiment will be described in detail later.

[0021] The font management unit 112 and the rasterization unit 113 perform the font rasterization process according to this embodiment to generate a font cache representing the characters to be drawn in the text document, or to outline the characters to be drawn and generate an object.

[0022] The rendering unit 114 uses the font cache or objects generated by the font rasterization process according to the present embodiment in accordance with the drawing commands included in the PDL data to draw each character in the text document and generate image data.

[0023] The job management unit 115 executes a predetermined job, such as a print job or a transmission job, on the image data generated by the rendering unit 114 .

[0024] In this embodiment, characters included in a text document are assumed to be in outline font. Character data for outline font includes, for example, a header containing character code, type style, character size, shape data indicating contours, and component information.

[0025] This information contained in the character data is registered in the character data by, for example, a font designer when creating an outline font.

[0026] The character code indicates a code based on Unicode for CJK (Chinese, Japanese, Korean) unified ideographs, for example. The type style indicates a font format such as Truetype or Opentype, for example. The outline indicates a line that connects coordinate points to form a closed shape.

[0027] The component information includes information for identifying the components that make up a character. The component information includes, for example, a maxp (maximum profile) table. The maxp table indicates the maximum values ​​of various parameters used to draw a character. The maxp table indicates, for example, the maximum number of points required to draw a component and the maximum number of contour lines.

[0028] Each functional unit such as the control unit 110 may be configured to be operable by a logic circuit rather than by operation based on a computer program, or may be configured to be realized by two or more control units.

[0029] The RAM 200 is used as a work memory. The RAM 200 includes a component storage area 210 and a font cache storage area 211. The component storage area 210 stores raster data of common components shared by multiple composite glyphs (hereinafter referred to as "first raster data"). The font cache storage area 211 stores a font cache indicating characters to be drawn.

[0030] The RAM 200 also stores a lookup table (hereinafter referred to as "LUT (Look Up Table)") 212 for referencing information about common components that characters in a text document have. The LUT 212 registers character codes, IDs of common components, the number of contours of the common components, and the coordinates of the starting points of the common components in association with each other.

[0031] As shown in, for example, FIG. 3, the LUT 212 registers, in association with each other, the character code "0x4FBF" for the composite glyph G1 of "bian", the ID "3" indicating the ID of the common component C1 corresponding to the radical "ninben", the number "1" indicating the number of outline lines, and the coordinates "(20, 50)" of the starting point.

[0032] JPEG2025173718000002.jpg45157

[0033] The ID of the common component is uniquely assigned to each common component. For a single glyph without a common component, the ID "0" is assigned. That is, a character with an ID indicating "0" is a single glyph, and a character with an ID indicating a value other than "0" is a composite glyph.

[0034] When the PDL data includes a text document, the character code, the ID of the common component, and the number of outline lines of the common component in the LUT 212 are obtained from the character data of the outline font in the text document and registered by the font management unit 112.

[0035] The coordinates of the starting point are registered in the LUT 212 for each composite glyph having the common component indicated by the first raster data by the rasterization unit 113 when the first raster data is stored in the component storage area 210. That is, the coordinates of the starting point are information indicating the presence or absence of the storage of the first raster data in the component storage area 210 for each composite glyph.

[0036] The control unit 100 is electrically connected to the image reading unit 11, the image forming unit 12, the fixing unit 13, the paper feeding unit 14, the display unit 15, the operation unit 16, the conveyance unit 17, the HDD 18, the image processing unit 19, the image memory 20, the facsimile communication unit 21, the communication unit 22, etc.

[0037] The display unit 15 is a display device including a liquid crystal display or an organic light-emitting diode (EL) display, and displays various screens.

[0038] The operation unit 16 includes a plurality of hard keys and a touch panel that is placed over the display unit 15. The operation unit 16 receives instructions from the user.

[0039] The conveying unit 17 includes a pair of conveying rollers 17A, a pair of discharge rollers 17B, and a conveying motor. The control unit 110 drives the conveying motor to rotate the pair of conveying rollers 17A and the pair of discharge rollers 17B, thereby conveying the paper P along the conveying path T.

[0040] The HDD 18 stores image data generated by the image reading unit 11, various computer programs for implementing the operations of the image forming apparatus 1, and the like. As part of the various computer programs, the HDD 18 stores a rasterization program for executing the font rasterization process according to this embodiment.

[0041] The HDD 18 stores a font cache previously generated by the rasterizer 113. The font cache is loaded into the font cache storage area 211 when the image forming apparatus 1 is started up.

[0042] The image processing unit 19 performs image processing as necessary on the image data generated by the image reading unit 11. The image memory 20 temporarily stores the image data generated by the image reading unit 11.

[0043] The facsimile communication unit 21 transmits and receives image data via a public line. The communication unit 22 includes a communication module such as a LAN (Local Area Network) board. The control unit 110 performs data communication via the communication unit 22 with an external device such as a PC (Personal Computer) 23 connected via the network.

[0044] A power supply is connected to each part of the image forming apparatus 1. When the power supply is turned on by a user, power is supplied to each part of the image forming apparatus 1 from the power supply.

[0045] [Operation] Hereinafter, the operation of the image forming apparatus 1 when executing the font rasterization process according to this embodiment will be described with reference to FIGS.

[0046] It is assumed that a user creates a text document and inputs a print instruction by operating a personal computer (PC) 23. The PC 23 generates a print job including PDL data using a printer driver included in the PC 23 and transmits the print job to the image forming apparatus 1.

[0047] When the communication unit 22 of the image forming device 1 receives a print job, the PDL interpretation unit 111 interprets the PDL data, and if it determines that the PDL data contains a text document, it requests the font management unit 112 and the rasterization unit 113 to register the LUT 212 and start executing the font rasterization process.

[0048] When the font manager 112 receives a registration request for the LUT 212, it obtains the character code and component information (in this case, the ID of the common component and the number of contours of the common component) from the character data of the outline font in the text document and registers them in the LUT 212.

[0049] [Font Rasterization] Referring to Figure 5, when a request to start the font rasterization process is received, the font management unit 112 determines the character to be drawn from multiple characters in the text document, and determines whether the font cache indicating the character to be drawn is stored in the font cache storage area 211 (step S10).

[0050] If the font manager 112 determines that a font cache indicating the character to be drawn is stored (YES in step S10), it does not need to generate a font cache, and therefore the font rasterization process ends.

[0051] On the other hand, if the font management unit 112 determines that the font cache indicating the character to be drawn is not stored (NO in step S10), the rasterization unit 113 refers to the RAM usage status and the maxp table, etc., and determines whether the work memory has sufficient free space to rasterize the character to be drawn (step S11).

[0052] If the rasterization unit 113 determines that the work memory does not have sufficient free space (NO in step S11), it outlines the characters to be drawn and generates an object representing the characters to be drawn (step S12). After processing step S12, the rasterization unit 113 ends the font rasterization process.

[0053] This prevents errors caused by insufficient memory due to rasterization of characters to be drawn when the work memory does not have sufficient free space.

[0054] On the other hand, if the rasterizing unit 113 determines that the work memory has sufficient free space (YES in step S11), it determines whether the character code of the character to be drawn is registered in the LUT 212 (step S13).

[0055] If the rasterization unit 113 determines that the character code of the character to be drawn is registered in the LUT 212 (YES in step S13), it determines whether the ID corresponding to the character code of the character to be drawn is "0" (step S14).

[0056] If the rasterization unit 113 determines that the ID corresponding to the character code of the character to be drawn is a value other than "0" (NO in step S14), that is, if the character to be drawn is a character classified as a composite glyph, it determines whether the first raster data is stored in the component storage area 210 (step S15).

[0057] (1) If the first raster data is not stored If the coordinates of the starting point are not registered in the LUT 212 in association with the character code of the character to be drawn, the rasterization unit 113 determines that the first raster data is not stored (NO in step S15), and starts executing the first raster data storage process shown in Figure 6 (step S16).

[0058] [First raster data storage process] When the first raster data storage process starts, the rasterization unit 113 first refers to the component information contained in the character data of each character in the text document and extracts from the text document all other characters that have the same components as the character to be drawn (step S30).

[0059] JPEG2025173718000003.jpg26157

[0060] After the process of step S30, the rasterizing unit 113 acquires the coordinates of the start points (in this case, the upper left corner point in the drawing) of the contours of the components of the character to be drawn and the extracted other characters (step S31).

[0061] JPEG2025173718000004.jpg35157

[0062] After processing in step S31, the rasterizing unit 113 extracts, as common components, components having common start point coordinates in the character to be drawn and the other extracted characters, based on the acquired start point coordinates (step S32).

[0063] In this case, the rasterizing unit 113 extracts, as a common component C3, a component indicating the radical "kusa-kanmuri" (grass radical) that has common coordinates P11, P21, etc., based on the acquired coordinates P11, P12, P21 to P29, etc. of the starting points. The rasterizing unit 113 does not extract non-common components that do not have common coordinates.

[0064] After the process of step S32, the rasterizing unit 113 generates first raster data indicating the extracted common component and stores it in the component storage area 210 (step S33). For example, as shown in Fig. 8, the rasterizing unit 113 generates first raster data R1 indicating the common component C3 and stores it in the component storage area 210. The first raster data R1 is a bitmap image of a size that allows the entire character L3, which is a composite glyph, to be drawn.

[0065] JPEG2025173718000005.jpg35156

[0066] 9, the rasterizing unit 113 associates the character code "0x82B1" of the character L4 "brown" with the coordinates "(10,300)" of the start point P31 of the common component C3 and registers them in the LUT 212. After processing step S34, the rasterizing unit 113 ends the first raster data storage process.

[0067] JPEG2025173718000006.jpg35155

[0068] In step S17, if the font cache of the non-common component is stored in the font cache storage area 211, the rasterizing unit 113 may generate the second raster data using the font cache.

[0069] After processing step S17, the rasterization unit 113 copies and reads the first raster data (in this case, the first raster data R1) from the component storage area 210, combines the read first raster data with the generated second raster data to generate a font cache indicating the character to be drawn, and stores the font cache in the font cache storage area 211 (step S18). After processing step S18, the rasterization unit 113 ends the font rasterization process.

[0070] (2) When the first raster data is stored On the other hand, if the coordinates of the starting point are registered in the LUT 212 in association with the character code of the character to be drawn, the rasterization unit 113 determines that the first raster data is stored (YES in step S15), and executes the processes of steps S17 and S18 without executing the first raster data storage process of step S16.

[0071] JPEG2025173718000007.jpg47155

[0072] The rasterizing unit 113 generates raster data R23 representing the character to be drawn by combining the first raster data R22 and the second raster data R21. The rasterizing unit 113 generates a font cache representing the character to be drawn using the raster data R23 and the character data, and stores the font cache in the font cache storage area 211.

[0073] If the rasterization unit 113 determines that the character code of the character to be drawn is not registered in the LUT 212 (NO in step S13), it directly generates a font cache representing the entire character to be drawn and stores it in the font cache storage area 211 (step S19).

[0074] As a result, for characters with unknown component information among the characters to be drawn, the first raster data is not used, and a font cache indicating the characters to be drawn is directly generated. As a result, it is possible to prevent characters with shapes unintended by font designers or the like from being drawn.

[0075] Further, when the rasterization unit 113 determines that the ID corresponding to the character code of the character to be drawn is "0" (YES in step S14), that is, when the character to be drawn is a character classified into a single glyph such as, for example, "免" or "丙", the process of step S19 is also executed. After the process of step S19, the rasterization unit 113 ends the font rasterization process.

[0076] When the font rasterization process ends, the rendering unit 114 uses the font cache stored in the font cache storage area 211 or the generated object in accordance with the drawing instruction included in the PDL data to draw the characters in the text document and generate image data. The job management unit 115 causes the image forming unit 12 or the like to form the image indicated by the generated image data on the paper P.

[0077] According to the above embodiment, when the character to be drawn in the text document has a common component and the first raster data is not stored in the component storage area 210, the rasterization unit 113 generates the first raster data using the character to be drawn and stores it in the component storage area 210. When the first raster data is stored in the component storage area 210, the rasterization unit 113 generates the second raster data indicating the non-common component in the character to be drawn, and combines the first raster data and the second raster data to generate a font cache indicating the character to be drawn and stores it in the font cache storage area 211.

[0078] In this way, when generating a font cache representing characters with common components, the previously generated first raster data is reused, eliminating the need to rasterize the common components again. As a result, the time required to rasterize characters classified as composite glyphs can be reduced compared to generating first raster data each time. Furthermore, consistency in the shapes of the common components can be achieved, improving the quality of the characters.

[0079] Furthermore, according to the above embodiment, when the rasterization unit 113 stores the first raster data in the component storage area 210, it updates the LUT 212 to indicate that the first raster data is stored for composite glyphs having a common component indicated by the first raster data.

[0080] This makes it possible to easily determine whether or not the first raster data is stored by referring to the LUT 212. This makes it possible to further reduce the time required to rasterize characters classified as composite glyphs.

[0081] Furthermore, according to the above embodiment, the rendering unit 114 generates image data using the font cache stored in the font cache storage area 210. This reduces the time required to draw characters in a text document.

[0082] Furthermore, according to the above embodiment, the image forming apparatus 1 includes the control unit 100 and the image forming unit 12 that forms on paper P an image represented by image data generated by the rendering unit 114. This reduces the time required for printing, thereby reducing the waiting time for the user.

[0083] (Other variations) In the above embodiment, the image forming apparatus 1 obtains a print job from the PC 23, but the present invention is not limited to such an embodiment. For example, the image forming apparatus 1 may obtain a print job from a mobile terminal such as a smartphone via wireless communication. Alternatively, the image forming apparatus 1 may obtain a text document from a USB memory via a USB (Universal Serial Bus) terminal and generate a print job.

[0084] In the above embodiment, the job management unit 115 causes the image forming unit 12 and the like to form an image indicated by the generated image data on the paper P, but the present invention is not limited to such an embodiment. For example, the job management unit 115 may store the generated image data in the HDD 18 in accordance with a user instruction received from the PC 23, or may transmit the generated image data to an external device via the facsimile communication unit 21 or the communication unit 22.

[0085] In the above embodiment, the control unit 100 functioning as a data processing device is mounted on the image forming apparatus 1, but the present invention is not limited to such an embodiment. For example, the control unit 100 functioning as a data processing device may be mounted on the PC 23.

[0086] In the above embodiment, the rasterizing unit 113 copies and reads out the first raster data R1 from the component storage area 210 in step S18, but the present invention is not limited to such an embodiment. For example, the rasterizing unit 113 may generate a font cache for the character to be drawn using the first raster data R1 stored in the component storage area 210 as is, and after the job management unit 115 completes the job, delete the second raster data from the raster data of the character to be drawn to generate the first raster data and store it again in the component storage area 210.

[0087] In the above embodiment, the image forming unit 12 etc. forms an image on paper P, but the present invention is not limited to such an embodiment. The image forming unit 12 etc. may form an image on, for example, an OHP (Overhead Projector) sheet.

[0088] The present invention is not limited to the above-described embodiment and modified examples, and various modifications are possible. For example, in the above-described embodiment, a color multifunction peripheral is used as the image forming apparatus 1, but this is merely an example, and other image forming apparatuses such as a monochrome multifunction peripheral, a copier, or a facsimile machine may also be used.

[0089] The configurations and processes of the above-described embodiment and modified examples shown with reference to FIGS. 1 to 10 are merely one embodiment of the present invention, and the present invention is not limited to these configurations and processes. [Explanation of symbols]

[0090] 1. Image forming device 12 Image forming unit 100 Control unit (data processing device) 113 Rasterization section 114 Rendering Department 200 RAM 210 Component Storage Area 211 Font cache storage area 212 LUT

Claims

1. a storage unit including a component storage area and a font cache storage area; When a character to be rendered in a text document has a common component that is shared by multiple composite glyphs, if first raster data indicating the common component is not stored in the component storage area, generating the first raster data using the character to be drawn and storing the first raster data in the component storage area; a rasterization unit that, when the first raster data is stored in the component storage area, generates second raster data indicating non-common components in the character to be drawn, combines the first raster data and the second raster data to generate a font cache indicating the character to be drawn, and stores the font cache in the font cache storage area.

2. a reference table indicating whether the first raster data is stored in the component storage area for each composite glyph; 2. The data processing device according to claim 1, wherein when the rasterization unit stores the first raster data in the component storage area, the rasterization unit updates the reference table to indicate that the first raster data is stored for a composite glyph having the common component indicated by the first raster data.

3. 2. The data processing apparatus according to claim 1, further comprising a rendering unit that uses the font cache stored in the font cache storage area to draw the characters in the text document and generate image data.

4. a data processing device according to claim 3; an image forming unit that forms an image represented by the image data generated by the rendering unit on a sheet of paper.

Images