JP4667464B2 - Image information generating apparatus, image information generating method, image information generating program, and recording medium - Google Patents

Description

  The present invention relates to an image information generation apparatus for generating image information such as characters and figures for an apparatus that forms images such as characters and figures such as a display device such as a liquid crystal display and a printing device such as a printer. About. The present invention also provides an image information generation method for generating image information such as characters and graphics by an image information generation apparatus, an image information generation program in which a processing procedure by the image information generation method is described, and the program is recorded. The present invention relates to a computer-readable recording medium. The image information generating apparatus of the present invention can be applied to display devices such as personal computers, mobile phones, digital televisions, etc., electronic devices including printing devices, and general information devices.

  A display device such as a liquid crystal display usually has a lower resolution than a printing device such as a printer due to technical limitations. For this reason, the image information such as characters and graphics displayed on the display screen of the display device may have lower definition and inferior quality than the image information such as characters and graphics printed on the printed surface of the printed matter. Many.

  A color liquid crystal display is usually configured such that, on a display screen in which pixels are arranged in a matrix, each pixel is arranged with, for example, three sub-pixels that display R, G, and B colors in the horizontal direction. In such a display screen, when characters, graphics, etc. are displayed, there is a possibility that coloring, character collapse, etc. may occur. Therefore, a method of displaying characters, graphics, etc. with high definition has been proposed.

  For example, Patent Document 1 (Japanese Patent No. 3552094) describes a method of displaying characters and figures with high definition on a display screen such as a color liquid crystal display. In this method, first, one subpixel is assigned to each pixel for the stroke forming the skeleton so that the skeleton of the character is displayed in units of subpixels. When the stroke is a vertical line, subpixels that are continuous in the vertical direction are assigned as skeleton subpixels. The skeleton subpixel is set to the maximum color element level, and a color element level lower than the maximum color element level is assigned to the subpixel adjacent to the skeleton subpixel. In this way, when color element levels are assigned to the skeleton subpixel and its surrounding subpixels, by controlling each subpixel at a luminance level corresponding to the color element level assigned to each subpixel, Characters, graphics, etc. are displayed in high definition on the display screen.

  FIG. 17 shows a schematic configuration of the character display device 100 disclosed in Patent Document 1. The character display device 100 includes an output device 200 as a display device capable of color display, and a control unit 300 that controls image information displayed on the display screen of the output device 200. The output device 200 has a display screen in which pixels are arranged in matrix information, and each pixel is composed of, for example, three sub-pixels R, G, and B arranged in the horizontal direction. . The control unit 300 is configured to independently control the luminance value (luminance level) of each sub-pixel on the display screen. The control unit 300 includes a main memory 310 and a CPU 320, and the CPU 320 is connected to the output device 200, the input device 400, and the auxiliary storage device 500.

  The auxiliary storage device 500 stores a display program 510 for displaying characters on the output device 200, which is a display device, and data 520 necessary for executing the display program 510 by the control unit 300. The data 520 includes character shape data 520a, a correction table 520b, and a luminance table 520c. The character shape data 520a stores, for example, skeleton data representing the skeleton shape of the character, outline data representing the outline shape of the character, and the like as data for defining the shape of the character. The correction table 520b stores a correction pattern for setting a color element level of a sub-pixel adjacent to a skeleton sub-pixel set corresponding to the character skeleton.

  In the correction table, color element levels for three or four subpixels adjacent to the skeleton subpixel are set, the maximum color element level is set for the skeleton subpixel, and the skeleton subpixel is adjacent. Three or four subpixels are each assigned a color element level lower than the maximum color element level.

  In the luminance table 520c, the relationship between the color element level and the luminance level set for each subpixel corresponding to R, G, and B is set.

  Character display apparatus 100 having such a configuration performs character display processing according to the processing procedure shown in FIG.

  When a character code and a character size are input from the input device 400 in step S1001 of FIG. 18, skeleton (skeleton) data for one character is stored in the main memory 310 in step S1002. Skeleton data is data indicating a skeleton portion of a character, and skeleton data is a set of stroke data indicating a line segment.

  Next, in step S1003, the coordinate data of the stroke data in the skeleton data is scaled based on the input character size. In step S1004, data for one stroke is extracted.

  Next, when it is determined in step S1005 that the stroke is a straight line (Yes), the process proceeds to step S1006, and subpixels on the straight line are defined as the basic portion (skeleton) of the character. On the other hand, if it is determined in step S1005 that the stroke is not a straight line (No), the process proceeds to step S1007, and the subpixel on the curve is defined as the basic portion (skeleton) of the character.

  Next, in step S1008, the color element level of the skeleton subpixel corresponding to the basic portion (skeleton) of the character is determined, and in step S1009, the correction table 520b is used to horizontally adjoin the skeleton subpixel. Determine the color element levels of 3 or 4 sub-pixels.

  Next, in step S1010, when all the strokes included in one character have not been processed (No), the process returns to step S1003 and is repeated. On the other hand, if all the strokes included in one character are processed in step S1010 (Yes), the process proceeds to step S1011 and the color element level of the sub-pixel is converted into a luminance level using the luminance table 520c.

  Finally, in step S1012, the luminance data indicating the luminance level of the sub-pixel is transferred to the output device 200 as a display device, and the process ends.

  According to the method disclosed in Patent Document 1, the character is controlled by appropriately controlling the color element level and the luminance level of the subpixel adjacent to the skeleton subpixel set corresponding to the skeleton of the character. Even when the line width of the stroke to be configured is changed for display, high-definition and smooth display can be performed.

  Further, in Patent Document 2 (Japanese Patent Application Laid-Open No. 2003-248476), a pixel of interest is extracted based on an array of skeleton subpixels set corresponding to the skeleton of a character, and each sub constituting the pixel of interest is extracted. A method for changing the luminance value of a pixel is described.

  FIG. 19 is a block diagram showing a schematic configuration of the character display device disclosed in Patent Document 2, and FIG. 20 is a flowchart of processing executed by the character display device.

  In FIG. 19, the character display device 101 independently outputs an output device 200 configured by a display device capable of color display and a plurality of luminance values (luminance levels) corresponding to a plurality of subpixels included in the output device 200. And a control unit 300 that performs control. The control unit 300 includes a main memory 310 and a CPU 320, and the CPU 320 is connected to the output device 200, the input device 400, and the auxiliary storage device 501. The output device 200 has the same configuration as the output device 200 shown in FIG.

  The auxiliary storage device 501 stores a display program 511 and data 521 necessary for executing the display program 511 by the control unit 300. The data 521 has character shape data 521a and a pixel value table 521d. The character shape data 521a stores, for example, skeleton data representing the skeleton shape of the character, outline data representing the outline shape of the character, bitmap data representing the character, and the like as data for defining the shape of the character. The pixel value table includes M + 2 × 2 sub-pixels including M sub-pixels included in the pixel of interest whose luminance level is determined and N sub-pixels adjacent to both sides thereof. For the arrangement pattern of the basic part (skeleton), the luminance levels (pixel values of pixels) of M sub-pixels included in the pixel of interest are set.

  Character display processing is performed by the character display device 101 having such a configuration based on the processing procedure shown in the flowchart of FIG.

  When a character code and a character size are input from the input device 400 in step S1001 in FIG. 20, skeleton data for one character is stored in the main memory 310 in step S1002.

  In step S1003, the coordinate data of the stroke data included in the skeleton data is scaled based on the input character size. In step S1004, data for one stroke is extracted.

  Next, when it is determined in step S1005 that the stroke is a straight line (Yes), the process proceeds to step S1006, and subpixels on the straight line are defined as the basic portion (skeleton) of the character. On the other hand, if it is determined in step S1005 that the stroke is not a straight line (No), the process proceeds to step S1007, and the subpixel on the curve is defined as the basic portion (skeleton) of the character. The processing so far is the same as the processing by the character display device 100 of Patent Document 1 shown in FIG.

  Next, in step S1010, when all the strokes included in one character have not been processed (No), the process returns to step S1003 and is repeated. On the other hand, if all strokes included in one character have been processed in step S1010 (Yes), the process proceeds to step S1101, and the arrangement pattern of subpixels adjacent to the target subpixel is examined.

  In step S1102, the pixel value table 521d is searched, and the luminance level of the subpixel corresponding to the arrangement pattern of the neighboring subpixels is set for the pixel of interest.

  Finally, in step S1103, the luminance data indicating the luminance level of the sub-pixel is transferred to the output device 200 such as a display device, and the process ends.

According to the method disclosed in Patent Document 2, the color element level and the luminance level of the subpixel adjacent to the skeleton subpixel corresponding to the skeleton of the character are appropriately set by the process simplified compared to Patent Document 1. It is possible to control, and even when the width of strokes constituting the character is changed and displayed, high-definition and smooth display can be performed. Furthermore, in this patent document 2, with respect to the skeleton subpixels that are close to each other, the position of the skeleton subpixel is moved so as to ensure the space between the skeleton subpixels, and then based on the arrangement of the skeleton subpixels. A method for setting the luminance value of each sub-pixel included in the pixel of interest has also been proposed. Thereby, it is possible to prevent the display screen from being displayed in a state where characters are crushed.
Japanese Patent No. 352094 JP 2003-248476 A

  In Patent Document 1, when strokes constituting a character are close to each other, when setting a color element level for a subpixel sandwiched between skeleton subpixels of each stroke, It is disclosed that a correction pattern defined by an element level array is properly used. However, this Patent Document 1 does not disclose in particular what kind of reference should be used for the correction pattern and what kind of correction pattern should be effective. Therefore, it is necessary to prepare a correction pattern in which color element levels are appropriately set for the subpixels sandwiched between the skeleton subpixels using the method disclosed in Patent Document 1. In order to prepare a correct correction pattern, there is a problem that it takes a lot of time and labor.

  In addition, as described in Patent Document 2, in the method of moving the position of the skeleton subpixel so as to ensure the space between the skeleton subpixels that are close to each other, the interference of the gradation pattern causes It can suppress that coloring (color noise) generate | occur | produces between the strokes displayed by a skeleton subpixel, and also can suppress that a character is displayed like being crushed. However, in the case where a plurality of skeleton subpixels are arranged side by side, since there are many combinations of which skeleton subpixels are to be moved, determination of the skeleton subpixels to be moved becomes complicated, There is a risk that it cannot be processed quickly. In actual characters, there are many cases in which a plurality of strokes are arranged, and in such a case, it is not easy to suppress coloring when displaying and to prevent the characters from being crushed and displayed. There is a problem.

  The present invention solves the above-described conventional problems, and is an image that can reliably suppress the occurrence of coloring between strokes approaching each other and the display of characters being crushed and displayed. An object is to provide an information generation apparatus, an image information generation method, an image information generation program, and a computer-readable recording medium on which the image information generation program is recorded.

  An image information generation apparatus according to the present invention is an image information generation apparatus that generates image information of characters or graphics for output to a display device, the display device including a plurality of pixels, and each of the plurality of pixels. Includes a plurality of sub-pixels arranged in a predetermined first direction, and a plurality of different color elements are assigned to the plurality of sub-pixels. Skeleton subpixel setting means for setting at least one subpixel corresponding to the skeleton portion as at least one skeleton subpixel; and at least adjacent to the skeleton subpixel along the skeleton subpixel and the predetermined first direction Color element level setting means for setting a color element level for each of the sub-pixels, and adjacent to each other along the predetermined first direction Determining means for determining whether or not there are two skeleton subpixels, and two skeleton subpixels when it is determined that there are two skeleton subpixels adjacent to each other along the predetermined first direction. Calculating means for calculating a distance between subpixels, and for flattening a luminance level corresponding to a color element level of a plurality of subpixels located between the two skeleton subpixels based on the calculated distance A flattening rate setting unit for setting a flattening rate; and a flattening unit for flattening the luminance levels of the plurality of subpixels positioned between the two skeleton subpixels based on the set flattening rate. It has.

  Preferably, R (red), G (green), and B (blue) are respectively assigned as color elements to the plurality of sub-pixels included in a single pixel in the display device.

  Preferably, the flattening rate setting unit sets the flattening rate for each of a plurality of subpixels included in a pixel of interest located between the two skeleton subpixels.

  Preferably, the flattening rate setting means sets the flattening rate so that the flattening rate increases as the distance between the two skeleton subpixels decreases.

  Preferably, when there are at least two skeleton subpixels continuous along a predetermined second direction orthogonal to the predetermined first direction, the flattening rate setting means includes the predetermined second The flattening rate is set so that the flattening rate becomes higher as the number of continuous skeleton subpixels along the direction increases.

  Preferably, the color element level setting means sets a maximum color element level to the skeleton subpixel and is a subpixel adjacent to the skeleton subpixel along the predetermined second direction, When there is a subpixel that is not a subpixel, the color element level setting means sets the subpixel as a skeleton-equivalent subpixel and sets a color element level smaller than the maximum color element level in the skeleton-equivalent subpixel. Then, the calculation means processes the skeleton-equivalent subpixel in the same manner as the skeleton subpixel.

  Preferably, when the stroke constituting the skeleton portion is an oblique line, at least one skeleton subpixel and at least one skeleton-equivalent subpixel are specified for the oblique line, and the color element level setting is performed. The means sets a maximum color element level for the skeleton subpixel, the color element level setting means sets a color element level smaller than the maximum color element level for the skeleton-equivalent subpixel, and the calculation means The skeleton-equivalent subpixel is processed in the same manner as the skeleton subpixel.

  The image information generation method of the present invention is an image information generation method for generating image information of characters or graphics for output to a display device, the display device including a plurality of pixels, and each of the plurality of pixels. Includes a plurality of sub-pixels arranged in a predetermined first direction, and a plurality of different color elements are assigned to the plurality of sub-pixels. Setting at least one sub-pixel corresponding to the skeleton portion as at least one skeleton sub-pixel, and at least one sub-pixel adjacent to the skeleton sub-pixel along the predetermined first direction and the skeleton sub-pixel Each of which includes a step of setting a color element level and two skeleton subpixels adjacent to each other along the predetermined first direction. A step of determining whether or not two skeleton subpixels are adjacent to each other along the predetermined first direction, and calculating a distance between the two skeleton subpixels. Setting a flattening rate for flattening a luminance level corresponding to color element levels of a plurality of subpixels positioned between the two skeleton subpixels based on the calculated distance; Flattening brightness levels of the plurality of sub-pixels positioned between the two skeleton sub-pixels based on the set flattening rate.

  Moreover, this invention is an image information generation program for making a computer perform each step of the said image information generation method.

  Further, the present invention is a computer-readable recording medium on which the image information generation program is recorded.

  According to the present invention, the luminance levels of the sub-pixels sandwiched between the skeleton sub-pixels and the skeleton-equivalent sub-pixels set corresponding to the skeleton parts such as characters and graphics and the parts corresponding to the skeleton are flattened. Controlled. As a result, even when strokes constituting characters, figures, etc. are close to each other, there is no possibility of coloring between strokes, and adjacent strokes are displayed in close contact with each other. Therefore, it is possible to suppress the characters and the like from being crushed and displayed. Further, when adjacent strokes are not close to each other, the outline of each stroke can be clearly displayed, and as a result, characters, figures, and the like can be clearly displayed.

  Furthermore, using the length information of the stroke represented by the length of the subpixel corresponding to the stroke forming the skeleton, the length of the skeleton subpixel and the skeleton-equivalent subpixel, the longer the stroke, the position between the strokes. By flattening the luminance levels of the subpixels with a high flattening rate, coloring between the strokes can be reliably suppressed even if the strokes are close to each other over a long range.

FIG. 1 is a block diagram showing a main configuration of an image information generation apparatus according to Embodiment 1 of the present invention. FIG. 2 is a flowchart for explaining image information generation processing performed based on the image information generation program by the image information generation apparatus according to the first embodiment. FIGS. 3A to 3C are diagrams each showing an example of a correction pattern table in the image information generation apparatus of the present invention. FIG. 4 is a diagram illustrating an example of a gradation pattern reference table in the image information generation apparatus according to the first embodiment. FIG. 5 is a diagram illustrating an example of an arrangement of skeleton subpixels of the Chinese character “busy” on the display screen. FIGS. 6A and 6B are diagrams each illustrating an example of a skeleton proximity table in the image information generation apparatus according to the first embodiment. FIG. 7 is a diagram illustrating an example of a flattening rate table in the image information generation apparatus according to the first embodiment. FIGS. 8A to 8C are explanatory diagrams of examples of flattening the luminance level by the image information generating apparatus of the first embodiment. FIG. 9 is a block diagram showing a main configuration of an image information generation apparatus according to Embodiment 2 of the present invention. (A)-(c) of FIG. 10 is a figure which shows an example of the frame | skeleton proximity | contact degree table in the image information generation apparatus of Embodiment 2, respectively. FIG. 11 is a diagram illustrating an example of a luminance table in the image information generation apparatus according to the second embodiment. FIG. 12 is a flowchart for explaining image information generation processing performed based on an image information generation program by the image information generation apparatus according to the second embodiment. FIGS. 13A to 13D are explanatory diagrams in the case where the luminance level is flattened by the image information generation apparatus according to the second embodiment. 14A to 14C are explanatory diagrams of other examples in the case where brightness level flattening control is performed by the image information generation apparatus of the second embodiment. FIG. 15 is a diagram illustrating an example of a flattening reinforcement rate table used in the image information generation device according to the embodiment of the present invention. (A) to (d) of FIG. 16 are diagrams illustrating an example of the flattening process of the luminance levels of the three sub-pixels R, G, and B, respectively. FIG. 17 is a block diagram showing the main configuration of the character display device disclosed in Patent Document 1. As shown in FIG. FIG. 18 is a flowchart for explaining a character display process performed by the character display device disclosed in Patent Document 1. FIG. 19 is a block diagram showing the main configuration of the character display device disclosed in Patent Document 2. As shown in FIG. FIG. 20 is a flowchart for explaining a character display process performed by the character display device disclosed in Patent Document 2.

Explanation of symbols

1A, 1B Image information generation device 2 Input unit 3 Control unit 4 Output unit 5A, 5B Auxiliary storage device 51A, 51B Image information generation program 52A, 52B Data 52a Skeletal proximity table 52b Flattening rate table 52c Tone pattern reference table 52d Correction table 53a Skeletal proximity table 53b Flattening rate table 53c Tone pattern reference table 53d Correction table 53e Luminance table

  Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1>
FIG. 1 is a block diagram showing a main configuration of an image information generating apparatus 1A according to Embodiment 1 of the present invention.

  An image information generation apparatus 1A shown in FIG. 1 includes an input unit 2, a control unit 3, an output unit 4, and an auxiliary storage device 5A.

  As the image information generation device 1A, for example, a personal computer including a color display device as an output unit may be used. As the personal computer, any type of computer such as a desktop type or a laptop type may be used. Alternatively, the image information generating apparatus 1A may be a word processor.

  Furthermore, the image information generation apparatus 1A may be an arbitrary device such as a color display device capable of color display, an electronic device provided with a print device capable of color printing, or an information device, such as a portable information terminal, It may be a mobile phone such as PHS, a general phone, a communication device such as FAX, an electronic device, or a portable information tool.

  The input unit 2 is used to input various information for designating characters, graphics, and the like to be generated to the control unit 3. Examples of information for designating a character include a character code for identifying the character, a character size indicating the size of the character, and the like.

  As the input unit 2, an input device such as a keyboard, a mouse, and a pen input device can be used. The input unit 2 may be a communication interface that can accept information from an external device, device, or the like.

  The control unit 3 includes a CPU 31 and a main memory 32, and the CPU 31 is connected to the input unit 2, the output unit 4, and the auxiliary storage device 5A.

  The CPU 32 controls and monitors the entire image information generation apparatus 1. Further, when the CPU 32 receives the information input to the input unit 2, it stores it in the main memory 31. Further, the image information generation program stored in the auxiliary storage device 5A is read, and the image information generation process is executed based on the image information generation program. Information such as the generated characters and graphics is output to the output unit 4.

  The output unit 4 is a display device such as a liquid crystal display or a printing device such as a printer. The output unit 4 may be a communication interface or the like that can output information to an external device, device, or the like.

  When the output unit 2 is a general color liquid crystal display device, each of a plurality of pixels (pixels) arranged in a matrix on the display screen, for example, red (R), green (G), blue (B ) Are assigned in stripes along a predetermined direction, for example, the horizontal direction. Then, by controlling the brightness value (brightness (gradation) level) indicating the brightness level of each sub-pixel independently by the control unit 3, image information such as desired characters and figures is generated, By controlling the display color of each sub-pixel based on the generated image information, images such as characters and figures are displayed on the display screen.

  The auxiliary storage device 5A stores an image information generation program 51A and data 52A used by the image information generation program 51A.

  The image information generation program 51A is a program for executing the image information generation processing of this embodiment by the control unit 3. The image information generation program 51A sets at least one subpixel corresponding to a skeleton portion (skeleton) of a character or a figure as at least one skeleton subpixel, sets the maximum color element level in the skeleton subpixel, and sets the skeleton subpixel. Each of the at least one subpixel adjacent to the pixel is assigned a color element level lower than the maximum color element level, and there are also two skeletal subpixels adjacent to each other in a predetermined direction (eg, lateral direction) If there are two skeleton subpixels that are adjacent to each other in the predetermined direction (for example, the horizontal direction), the distance between the two skeleton subpixels is calculated and calculated. Based on the measured distance, the color element levels (or possibly the subpixels) located between the two skeleton subpixels. , It carries out a process of flattening the luminance level).

  As the data 52A, a skeleton proximity table 52a, a flattening rate table 52b, a gradation pattern reference table 52c, and a correction table 52d are stored.

  In the correction table 52d, color element levels for three or four subpixels adjacent to the skeleton subpixel are set based on the line width when displayed on the display screen.

  In the skeleton proximity table 52a, skeleton proximity is set based on the distance between the skeleton subpixels adjacent to each other in the horizontal direction in the skeleton subpixels set corresponding to the skeleton portion of the character or figure. Yes. Skeletal proximity is divided into groups according to the number of pixels that exist between skeleton subpixels that are adjacent to each other in the horizontal direction, and when skeleton subpixels that are adjacent to each other in the horizontal direction exist. This is used to determine the skeleton proximity between the skeleton subpixels.

  In the flattening rate table 52b, the luminance level (gradation level) of the sub-pixels sandwiched between the skeleton sub-pixels is flattened based on the skeleton proximity of the skeleton sub-pixels adjacent to each other in the horizontal direction ( A flattening rate for equalization is set. Based on this flattening rate, the luminance level of the subpixels sandwiched between the skeleton subpixels is controlled to be flattened uniformly.

  The gradation pattern reference table 52c is a luminance for the color element level set for each of the three sub-pixels constituting each pixel in order to control the luminance level of the sub-pixel sandwiched between the skeleton sub-pixels in units of pixels. Levels are preset. The subpixels sandwiched between the skeleton subpixels have color element levels set for three or four adjacent to the skeleton subpixel by the correction table 52d, but are adjacent to each other obtained from the skeleton proximity table 52a. The flattening rate set in the flattening rate table 52b is set from the skeleton proximity of the skeleton subpixel, and the brightness pattern leveled by the set flattening rate is set in the gradation pattern reference table 52c. Based on this, the luminance level of each sub-pixel is set.

  As the auxiliary storage device 5A, any type of storage device capable of storing the image information generation program 51A and the data 52A is used. In the auxiliary storage device 5A, an arbitrary recording medium is used as a recording medium for storing the image information generation program 51A and the data 52A. For example, a recording medium such as a hard disk, CD-ROM, MO, floppy (registered trademark) disk, MD, DVD, IC card, or optical card is preferably used.

  The image information generation program 51A and the data 52A are not limited to being stored in a recording medium in the auxiliary storage device 5A. For example, the image information generation program 51A and the data 52A may be stored in the main memory 31 or may be stored in a ROM (not shown). For example, a mask ROM, EPROM, EEPROM, flash ROM, or the like is used as the ROM. When a ROM is used, various processing variations can be easily realized simply by exchanging the used ROM. Therefore, the ROM can be suitably applied to a portable terminal device, a cellular phone, and the like. it can.

  Further, the recording medium for storing the image information generation program 51A and the data 52A is a program in a communication network other than a medium that holds the program and data fixedly, such as a storage device such as a disk or a card or a semiconductor memory. Or a medium that fluidly carries programs and data, such as a communication medium used to carry data.

  When the character display device 1 includes means for connecting to a communication line including the Internet, the image information generation program 51A and the data 52A can be downloaded from the communication line. In this case, a loader program necessary for downloading may be stored in advance in a ROM (not shown), or may be installed in the control unit 3 from the auxiliary storage device 5A.

  The image information generation process performed based on the image information generation program 51A in the image information generation apparatus 1A having such a configuration will be described based on the flowchart shown in FIG.

  First, when a character code and a character size are input to the input unit 2, a line width parameter is acquired based on the character size (see step S1 in FIG. 2, the same applies hereinafter). The line width parameter defines the line width of vertical lines and diagonal lines in generated characters and figures. For example, “thin”, “normal”, “thick” based on the input line width parameter. The line width is defined.

  When the line width parameter is acquired in step S1, a skeleton subpixel, which is a subpixel corresponding to character or figure skeleton data, is set, the maximum color element level is set for the skeleton subpixel, Based on the line width defined by the width parameter, the color element levels of three or four subpixels (correction pattern length) adjacent to the skeleton subpixel are set based on the correction table 52d.

  The color element level is defined as the degree to which the color element of each sub-pixel contributes to the display of characters or graphics.

  The color element levels are, for example, “7”, “6”, “5”, “4”, “3”, “2”, “1”, “1”, “7”, and “0” as the minimum value. “0” is set to 8 levels, and “0”, “35”, “73”, “109”, “146”, “182”, Eight levels of luminance levels “219” and “255” are assigned, respectively. Accordingly, “7” which is the maximum color element level is set in the skeleton subpixel, and the luminance level “255” corresponding to the maximum color element level “7” is set in the color display device of the output unit 4. The

  The number of sub-pixels (correction pattern length) adjacent to the skeleton sub-pixel for which the color element level is set is set to either 3 or 4 based on the configuration of the output unit or the like. An example of the correction pattern 52d is shown in FIG. FIG. 3A is a correction table for setting color element levels for three subpixels adjacent to the skeleton subpixel, and the line widths “thin” and “normal” defined by the line width parameter are shown in FIG. , Corresponding to “thick”, the color element levels of the three sub-pixels are respectively set.

  For example, when the line width parameter is “thin”, the color element levels of three subpixels adjacent to the skeleton subpixel are “3” and “1” for each subpixel in order from the skeleton subpixel. , “0”, respectively. When the line width specified by the line width parameter is “normal”, the color element levels of the three subpixels adjacent to the skeleton subpixel are “4”, “3”, Set to “2” respectively. Further, when the line width specified by the line width parameter is “thick”, the color element levels of the subpixels adjacent to the skeleton subpixel are “6”, “4”, “2” in order from the skeleton subpixel. Respectively.

  FIG. 3B is an example of a correction table when color element levels are set for three subpixels adjacent to the skeleton subpixel, and the line width defined by the line width parameter is “thin”. In some cases, the color element levels of four subpixels adjacent to the skeleton subpixel are set to “3”, “1”, “0”, and “0” in order from the skeleton subpixel. When the line width defined by the line width parameter is “normal”, the color element levels of the four subpixels adjacent to the skeleton subpixel are “4”, “3”, “2” and “0” are set, respectively. Further, when the line width defined by the line width parameter is “thick”, the color element levels of the four subpixels adjacent to the skeleton subpixel are “5”, “4”, “ 3 ”and“ 2 ”, respectively.

  In the following description, a case will be described in which the length of the correction pattern (the number of subpixels whose color element level is set adjacent to the skeleton subpixel) is 3 and the line width is “normal”. Accordingly, in step S2, according to the correction table of FIG. 3A, the three subpixels adjacent to the skeleton subpixel are color element levels of “4”, “3”, and “2” in order from the skeleton subpixel. Set to

  In this way, when the color element levels of the skeleton subpixel and three adjacent subpixels are set by the correction table 52d, the gradation corresponding to the number and line width of the subpixels for which the color element level is set. The pattern reference table 52c is acquired (step S2).

  Similar to the correction table, the gradation pattern reference table 52c is adjacent to the skeleton subpixel in each case of “thin”, “normal”, and “thick” which are line widths defined by the line width parameter. For each number (3 or 4) of sub-pixels for which the color element level is set, the color element levels that can be set for the three sub-pixels of R, G, and B constituting one pixel are patterned. In addition to being set, luminance levels corresponding to the color element levels set for the three sub-pixels R, G, and B in each pattern are set.

  FIG. 4 shows the order when the line width specified by the line width parameter is “normal” and the length of the correction pattern is 3 (the number of subpixels adjacent to the skeleton subpixel for which the color element level is set). An example of the key pattern reference table 52c is shown. In the gradation pattern reference table of FIG. 4, 23 color element level combination patterns are set for each of the R, G, and B sub-pixels, and the luminance levels corresponding to the color element levels of the respective combination patterns are set. Each is also set.

  In this way, when the correction table and the gradation pattern reference table are acquired, based on the arrangement of the skeleton subpixels, a skeleton subpixel and its skeleton are obtained for a pixel including one skeleton subpixel. A process of setting a predetermined luminance level is performed for each of the sub-pixels of the correction pattern length adjacent to the sub-pixels and the sub-pixels positioned between the skeleton sub-pixels adjacent in the horizontal direction (step S3). ).

  FIG. 5 is a diagram illustrating an example of a skeleton subpixel arrangement. In the example of FIG. 5, each pixel arranged in a matrix on the display screen of the color display device constituting the output unit 4 is composed of three R, G, and B subpixels arranged in the horizontal direction. , The skeleton part (skeleton) which is the basic part of the Chinese character “busy” is displayed on the display screen. In this case, in the coordinate system shown in FIG. 5, the lower left coordinate position is the origin O, and the subpixels indicated by hatching in FIG. 5 are set as skeleton subpixels. In this manner, the following processing is sequentially performed on pixels (pixels) in which one skeleton subpixel is set for one pixel.

  First, the maximum element level “7” is set for the skeleton subpixel based on the arrangement of the skeleton subpixel. Then, it is checked whether or not one skeleton subpixel included in one pixel is adjacent in the horizontal direction to form a skeleton subpixel pair (step S4). When there is a skeleton subpixel pair in which one skeleton subpixel included in one pixel is adjacent in the horizontal direction (Yes), the process proceeds to step S5, and when it does not exist (No), Proceed to step S9.

  If there is no adjacent skeleton subpixel pair in step S3, in step 9, it is adjacent to this skeleton subpixel based on the length of the correction pattern from the correction table 52d acquired in step S2. Color element levels are set for three or four subpixels, respectively. In the present embodiment, the line width defined by the line width parameter is “normal” and the length of the correction pattern is 3 (the number of subpixels adjacent to the skeleton subpixel in which the color element level is set). In addition, the three sub-pixels adjacent to the skeleton subpixel are set to “4”, “3”, and “2” in order from the skeleton subpixel.

  On the other hand, when there is a pair of adjacent skeleton subpixels, the size of the space (distance between the skeleton subpixels) sandwiched between the adjacent skeleton subpixel pairs is obtained (step S5). The size of this space is calculated based on, for example, the number of subpixels sandwiched between adjacent skeleton subpixel pairs. The size of the space between adjacent skeleton subpixel pairs can be obtained based on the difference in coordinate values corresponding to the respective positions of the skeleton subpixel pairs.

  In the following description, processing related to the skeleton subpixel A indicated by coordinates (14, 6) and the skeleton subpixel B indicated by coordinates (20, 6) in FIG. 5 will be described with reference to FIG. . FIG. 8A corresponds to FIG. 5, and FIG. 8B is an enlarged view of a portion surrounded by a dotted line in FIG. 8A. The skeleton subpixels A and B are adjacent to each other in the horizontal direction to form a skeleton subpixel pair. In this embodiment, the maximum color element level “7” is set for each of the skeleton subpixels A and B, and the line width defined by the line width parameter is “normal”, and the length of the correction pattern Is 3 (the number of subpixels adjacent to the skeleton subpixel for which the color element level is set), the three subpixels adjacent to the skeleton subpixel are “4” in order from the skeleton subpixel. Color element levels of “3” and “2” are respectively set.

  The size of the space of the skeleton subpixels A and B is calculated from the coordinate system shown in FIG. In this case, in the coordinate system shown in FIG. 5, the coordinate value of the horizontal axis (X axis) of the skeleton subpixel A is “14” and the coordinate value of the horizontal axis (X axis) of the skeleton subpixel B is “20”. Therefore, the size of the space sandwiched between the skeleton subpixels A and B is calculated as 5 (= 20-14-1), and it is determined that there are five subpixels between the skeleton subpixels A and B. It is done.

  Note that here, the distance between adjacent skeletons is defined using the size of the space between adjacent skeleton subpixel pairs, but simply the distance between two skeleton subpixels (the coordinates of two points). (Value difference) may be used.

  When the size of the space sandwiched between the skeleton subpixels A and B is calculated in step S5, the size of the space sandwiched between the adjacent skeleton subpixels A and B (the skeleton is based on the skeleton proximity table 52a. The skeleton proximity corresponding to (distance between) is read (step S6).

  FIG. 6 shows an example of the skeleton proximity table 52a. FIG. 6A shows a case where the length of the correction pattern (the number of subpixels adjacent to the skeleton subpixel in which the color element is set) is 3. When the size of the space between the skeleton subpixel pair is 5 subpixels or less, “level 1” is set as the skeleton proximity. When the size of the space between the skeleton subpixel pairs is 6 subpixels or more and 9 subpixels or less, “level 2” is set as the skeleton proximity, and further, between the skeleton subpixel pairs. When the size of the space is 10 or more, the skeleton proximity is set to “level 3”.

  FIG. 6B shows a case where the length of the correction pattern (the number of subpixels adjacent to the skeleton subpixel in which the color element is set) is 4, and the size of the space between the skeleton subpixel pair is 7. When it is less than or equal to sub-pixels, “level 1” is set as the skeleton proximity, and when it is 8 to 11 sub-pixels, “level 2” is set as the skeleton proximity. In some cases, “level 3” is set as the skeleton proximity.

  As shown in FIGS. 6A and 6B, by setting a skeleton proximity table corresponding to the length of the correction pattern, the influence of the length of the correction pattern on the coloration of the space is considered in detail. Proximity can be determined.

  In step S6, the skeleton proximity corresponding to the size of the space between the skeleton subpixel pairs is obtained based on such a skeleton proximity table 52a. In step S6, when the skeleton proximity corresponding to the size of the space between the skeleton subpixel pairs is obtained, the flattening rate corresponding to the obtained skeleton proximity is obtained based on the flattening rate table 52b. (Step S7). The flattening rate table 52b flattens the color element levels of the subpixels positioned between the skeleton subpixel pairs with respect to the skeleton proximity set corresponding to the size of the space between the skeleton subpixel pairs. A flattening rate, which is a ratio for (uniform), is set in advance and tabulated.

  FIG. 7 shows an example of the flattening rate table 52b. The flattening rate table is such that the gradation pattern of the subpixels positioned between the skeleton subpixel pairs becomes flatter as the distance between the skeleton subpixels adjacent to each other in the horizontal direction is narrower and the skeleton proximity is smaller. A large flattening rate is set. In FIG. 7, when the skeleton proximity is “level 1”, “0.8” is set as the flattening rate, and when the skeleton proximity is “level 2”, the flattening rate is “0”. .5 ”is set and the skeleton proximity is“ level 3 ”,“ 0 ”is set as the flattening rate.

  In step S7, when the flattening rate of the color element level of the sub-pixel located between the skeleton sub-pixel pairs is determined based on the skeleton proximity, R subtracts from all the sub-pixels located between the skeleton sub-pixel pairs. , G, and B are set as a pixel of interest, and the color element level set by the correction table for each of the R, G, and B subpixels that form the pixel of interest Is selected from the gradation pattern reference table 52c, and the luminance level for each of the R, G, and B sub-pixels constituting the pixel of interest is set and set from the luminance level pattern corresponding to the gradation pattern. Each luminance level thus obtained is flattened by the flattening rate obtained in step S7. (Step S8).

  As shown in FIG. 8B, the color element levels of the R, G, and B sub-pixels in the target pixel are “3”, “2”, and “3”, which are shown in FIG. No. in the gradation pattern reference table 52c. It corresponds to 12 color element level patterns. Accordingly, luminance levels of “146”, “182”, and “146” are set for the R, G, and B subpixels in the target pixel. Then, the brightness level set in this way is flattened by the flattening rate “0.8” obtained in step S7.

For example, when the luminance levels obtained by the gradation pattern reference table 52c are V _{R_ref} , V _{G_ref} , and V _{B_ref} for the R, G, and B subpixels in the _{target pixel} , the average of the luminance levels is obtained. When the value V _ave is calculated by the following equation (1-1) and the flattening rate is R _flat , the luminance levels V _{R_flat} , V _{G_flat} , and V _{B_flat} after the flattening are _expressed by the following equations (1-2) to (1) -4).

V _ave = (V _Rref + V _Gref + V _Bref ) / 3 (1-1)
V _Rflat = V _Rref + (V _ave −V _Rref ) × R _flat (1-2)
V _Gflat = V _Gref + (V _ave −V _Gref ) × R _flat (1-3)
V _Bflat = V _Bref + (V _ave −V _Bref ) × R _flat (1-4)
In the calculation of the flattening process, in order to perform weighting proportional to the brightness, instead of the luminance level value, the above formula (1) is used for values G _{R_ref} , G _{G_ref} , and G _{B_ref obtained} by gamma-converting the luminance level. The values G _Rflat , G _Gflat , and G _Bflat after flattening may be obtained by the following formulas (2-1) to (2-4) by applying (-1) to (1-4).

G _ave = (G _Rref + G _Gref + G _Bref ) / 3 (2-1)
G _Rflat = G _Rref + (G _ave −G _Rref ) × R _flat (2-2)
G _Gflat = G _Gref + (G _ave −G _Gref ) × R _flat (2-3)
G _Bflat = G _Bref + (G _ave −G _Bref ) × R _flat (2-4)
It is also possible to obtain luminance levels V _Rflat , V _Gflat , and V _Bflat that have been flattened by inverse gamma conversion from the flattened values G _{R_flat} , G _{G_flat} , and G _{B_flat} . Here, gamma conversion and inverse gamma conversion are defined by the following equations (3-1) to (3-2).

Gamma conversion: G = Gmax × (V / Vmax) ^γ (3-1)
Inverse gamma conversion: V = Vmax × (G / Gmax) ^{1 / γ} (3-2)
However, Gmax: maximum value of luminance level after gamma conversion (for example, 255)
Vmax: Maximum value of luminance level after inverse gamma conversion (for example, 255)
In this case, for example, γ = 2.2, and the gamma conversion and the inverse gamma conversion are nonlinear conversions. Thereby, weighting proportional to the brightness is performed, and the flattening process can be performed more effectively.

  As described above, the luminance levels of “146”, “182”, and “146” are set for the R, G, and B subpixels in the target pixel surrounded by the dotted line in FIG. The average value of these values is “158” from the equation (1-1). By substituting this average value and the luminance levels of the R, G, and B sub-pixels in the pixel of interest into the equations (1-2) to (1-4), the values of R, G, and B in the pixel of interest As the flattened luminance level of each sub-pixel, “156”, “163”, and “156” are obtained, respectively.

  Here, the planarization process in step S7 of FIG. 2 will be described in more detail. This flattening process is performed on a plurality of subpixels (for example, three subpixels R, G, and B) included in a single pixel. Flattening the luminance level of a plurality of subpixels included in a single pixel means that the luminance level of at least one subpixel of the plurality of subpixels approaches the average luminance level of the plurality of subpixels. , Correcting the luminance level of at least one subpixel of the plurality of subpixels. For example, if a single pixel includes three R, G, and B subpixels, the luminance level of at least one of the three subpixels is the average of the three subpixels. By correcting the luminance level of at least one of the three subpixels so as to approach the luminance level, the luminance level of the three subpixels can be flattened.

  16A to 16D show examples of processing for flattening the luminance levels of the three subpixels R, G, and B, respectively.

  In FIG. 16A, when the luminance levels of the three subpixels B, G, and R are monotonously decreasing in this order, the luminance level of the B subpixel is decreased so as to approach the average luminance level, An example of processing for flattening the luminance levels of the three sub-pixels B, G, and R by increasing the luminance level of the sub-pixels so as to approach the average luminance level will be described.

  In FIG. 16B, when the luminance levels of the three sub-pixels B, G, and R are monotonically increasing in this order, the luminance level of the B sub-pixel is increased so as to approach the average luminance level. An example of processing for flattening the luminance levels of the three sub-pixels B, G, and R by decreasing the luminance level of the sub-pixels so as to approach the average luminance level will be described.

  FIG. 16C shows that when the luminance level of the G sub-pixel is maximum, the luminance levels of the B and R sub-pixels are increased so as to approach the average luminance level, and the luminance level of the G sub-pixel is averaged. An example of processing for flattening the luminance levels of the three sub-pixels B, G, and R by reducing the luminance level so as to approach the luminance level will be described.

  FIG. 16D shows that when the luminance level of the G sub-pixel is minimal, the luminance levels of the B and R sub-pixels are decreased so as to approach the average luminance level, and the luminance level of the G sub-pixel is averaged. An example of processing for flattening the luminance levels of the three sub-pixels B, G, and R by increasing the luminance level so as to approach the luminance level will be described.

  The calculation formulas for flattening the luminance levels of the three sub-pixels R, G, and B are the aforementioned formulas (1-1) to (1-4) or formulas (2-1) to (2-4). It is as follows.

  By performing the above-described flattening process on a plurality of subpixels included in a pixel of interest located between two skeleton subpixels adjacent to each other along a predetermined direction (for example, a horizontal direction), the two skeletons The space between the subpixels can be made closer to an achromatic color. As a result, the occurrence of coloring between the skeleton portion and the skeleton portion can be suppressed.

  When the luminance level of the sub-pixel between the skeleton sub-pixel and the skeleton sub-pixel adjacent in the horizontal direction is set in step S8 or step S9, the brightness of the luminance level in which the sub-pixel in the display screen of the output unit 4 is set. A voltage value of a predetermined level is output to the output unit 4 so as to become (Step S10).

  Thereafter, it is checked whether or not there is a pixel to be processed. If there is (Yes), the process returns to step S4, and the processing of steps S4 to S10 is repeated for the pixel to be processed, and there is no pixel to be processed. In the case (No), the process is terminated (step S11).

  As described above, according to the present embodiment, when there is a skeleton subpixel pair in which skeleton subpixels corresponding to the skeleton portion of a character or a figure are adjacent to each other in the horizontal direction, the position is between the skeleton subpixel pairs. Since the luminance level of the target sub-pixel is flattened according to the distance between the skeleton sub-pixel pair, even when vertical lines are close in the image information of the generated characters and figures, It is possible to suppress occurrence of coloring between vertical lines. In this case, when the skeleton subpixel pair is not close, the luminance level of the target subpixel located between the skeleton subpixel pair is not flattened, so that image information with clear outlines of characters and figures is generated. can do.

<Embodiment 2>
FIG. 9 is a block diagram showing a main configuration of an image information generation apparatus 1B according to Embodiment 2 of the present invention. 9, description of components common to those in FIG. 1 is omitted.

  In FIG. 9, the image information generating apparatus 1B according to the second embodiment includes an input unit 2, a control unit 3, an output unit 4, and an auxiliary storage device 5B.

  The auxiliary storage device 5B stores an image information generation program 51B and data 53B used by the image information generation program 51B.

  The image information generation program 51B is a program for executing the image information generation processing of the present embodiment by the control unit 3. The image information generation program 51B sets the skeleton subpixel corresponding to the skeleton data so that the skeleton portion (skeleton) of the character or figure is configured in units of subpixels, and the maximum color for the skeleton subpixel. Assign element levels, assign sub-pixels adjacent to the skeleton subpixel to a color element level lower than the maximum color element level, and based on the distance between the skeleton subpixels adjacent to each other in the horizontal direction For the sub-pixels positioned between adjacent skeleton sub-pixels, a process of flattening and assigning the color element level is performed.

  As the data 53B, a skeleton proximity table 53a, a flattening rate table 53b, a gradation pattern reference table 53c, a correction table 53d, and a luminance table 53e are stored.

  In the correction table 53d, as in the correction table 53d in the first embodiment, the color element levels for three or four subpixels adjacent to the skeleton subpixel are set based on the line width displayed on the display screen. However, in this embodiment, in addition to the non-skeleton subpixel that is vertically adjacent to the skeleton subpixel and one or more subpixels that are horizontally adjacent to the subpixel. Thus, the color element level is set. In this case, a color element level lower than the maximum color element level set for the skeleton subpixel is set for the subpixel adjacent to the skeleton subpixel in the vertical direction, and the subpixel is set in the horizontal direction of the subpixel. Adjacent subpixels are set to a lower color element level. Then, subpixels that are not skeleton subpixels adjacent to the skeleton subpixel in the vertical direction are set as skeleton-equivalent subpixels, and the skeleton-equivalent subpixels are processed in the same manner as the skeleton subpixels in the subsequent processing.

  Similar to the skeleton proximity table 52a in the first embodiment, the skeleton proximity table 53a is a skeleton subpixel set corresponding to a skeleton portion of a character or a figure, and between skeleton subpixels adjacent to each other in the horizontal direction. The skeleton proximity is set based on the distance of the skeleton, and the skeleton proximity is also determined based on the distance from the skeleton subpixels (including the skeleton-equivalent subpixels) adjacent to the skeleton in the horizontal direction. Is set. For the skeleton-equivalent subpixel, the skeleton proximity corresponding to the set color element level is set.

  FIGS. 10A to 10C show an example of the skeleton proximity table 53a, and the number of subpixels (the length of the correction pattern) for which the color element level is set by the correction table is 3, respectively. . FIG. 10A is a skeleton proximity table used when skeleton subpixels for which the maximum color element level 7 is set are adjacent to each other in the horizontal direction, and the distance between the skeleton subpixels adjacent in the horizontal direction. When the number of subpixels positioned between adjacent skeleton subpixels is 5 or less, “level 1” is set as the skeleton proximity, and the number of subpixels is 6 to 9 “Level 2” is set as the skeleton proximity, and “Level 3” is set as the skeleton proximity when the number of sub-pixels is 10 or more.

  FIG. 10B illustrates a case where a skeleton-equivalent subpixel in which 6 to 4 is set as the color element level and the skeleton subpixel are adjacent in the horizontal direction, or a skeleton in which 6 to 4 is set as the color element level. This is a skeleton proximity table used when the corresponding sub-pixels are adjacent to each other in the horizontal direction, and the number of sub-pixels positioned between the skeleton-equivalent sub-pixels and the skeleton-equivalent sub-pixels or the skeleton sub-pixels adjacent to each other. When the number is 3 or less, “level 1” is set as the skeleton proximity, and when the number of subpixels is 4 to 6, “level 2” is set as the skeleton proximity. Is 7 or more, “level 3” is set as the skeleton proximity.

  FIG. 10C shows a case where a skeleton-equivalent subpixel in which “3” to “1” are set as color element levels and the skeleton subpixel are adjacent in the horizontal direction, or one or more color element levels are set. Is a skeleton proximity table used when the skeleton-equivalent subpixels are adjacent to each other in the horizontal direction, and is a subpixel located between the skeleton-equivalent subpixel and the skeleton-equivalent subpixel or the skeleton subpixel that are adjacent to each other “Level 2” is set as the skeleton proximity when the number of sub-pixels is 6 or less, and “Level 3” is set as the skeleton proximity when the number of sub-pixels is 7 or more.

  As described above, when the color element level ranges of the skeleton-equivalent subpixels adjacent to each other do not match, a skeleton proximity table having a small color element level range is used. Then, a plurality of skeleton proximity tables are provided in accordance with the color element levels set for the skeleton subpixel and the skeleton-equivalent subpixel, and thus are determined according to the color element levels of the skeleton subpixel and the skeleton-equivalent subpixel. Considering the influence of the shading of characters and figures on the collapse of the space, the skeleton proximity can be determined finely.

  The flattening rate table 53b has the same configuration as the flattening rate table 52b of FIG. 7 in the first embodiment, and when the skeleton proximity is “level 1”, the flattening rate is “0”. .8 ”is set, and when the skeleton proximity is“ level 2 ”,“ 0.5 ”is set as the flattening rate. When the skeleton proximity is “level 3”, “0.0” is set as the flattening rate, and the flattening process is not performed.

  The gradation pattern reference table 53c has the same configuration as the gradation pattern reference table 52c of FIG. 4 in the first embodiment.

  In the luminance table 53d, when a skeleton subpixel or a skeleton-equivalent subpixel is adjacent in the horizontal direction to the skeleton-equivalent subpixel, the skeleton-equivalent subpixel and the skeleton subpixel or the skeleton-equivalent subpixel that are adjacent in the horizontal direction. The luminance levels are set corresponding to the respective color element levels set for the sub-pixels positioned between and, and an example is shown in FIG. In the luminance table shown in FIG. 10, the luminance level of the subpixel whose color element level is “1” is “255” in any of R, G, and B, and the color element level is “2”. The luminance level of the sub-pixel is “219” in any of R, G, and B, and the luminance level of the sub-pixel having the color element level of “3” is in any of R, G, and B Is also “182”, the luminance level of the sub-pixel whose color element level is “4” is “109” in any of R, G, and B, and the sub-pixel whose color element level is “5”. The luminance level of the pixel is “73” in any of R, G, and B, and the luminance level of the sub-pixel having the color element level of “6” is in any of R, G, and B “36” and the color element level “7”. Degree level, R, in each case G, and B are "0".

  Hereinafter, image information generation processing performed based on the image information generation program 51B by the image information generation apparatus 1B of the present embodiment will be described based on the flowchart shown in FIG. 12 and the explanatory diagram of FIG. FIG. 13 is an explanatory diagram of processing when the Chinese character “busy” is displayed with the line width “normal” as in the first embodiment.

  First, when a character code and a character size are input to the input unit 2, a line width parameter is acquired based on the character size (see step S21 in FIG. 12, the same applies hereinafter). The line width parameter defines the line width of vertical lines and diagonal lines in generated characters and figures. For example, “thin”, “normal”, “thick” based on the input line width parameter. The line width is defined.

  When the line width parameter is acquired in step S21, a skeleton subpixel, which is a subpixel corresponding to character or figure skeleton data, is set, and the maximum color element level is set to the skeleton subpixel. Based on the line width defined by the width parameter, the color element levels of three or four subpixels (correction pattern lengths) adjacent in the horizontal direction of the skeleton subpixel are set based on the correction table 53d. At the same time, color element levels are set based on the correction table 53d for subpixels that are not skeleton subpixels adjacent to the skeleton subpixel in the vertical direction and subpixels on both sides of the subpixel.

  Regarding the skeleton subpixels A and B in the portion surrounded by the dotted line in FIG. 13A, five subpixels are located between the skeleton subpixels A and B, and the skeleton proximity in FIG. From the degree table, “level 1” is set as the skeleton proximity. Then, for the five sub-pixels positioned between the two skeleton sub-pixels A and B, as shown in FIG. 13C, the color element level is based on the correction table 53d as in the first embodiment. As a result, “4”, “3”, “2”, “3”, “4” are set in order from the sub-pixel adjacent to the skeleton sub-pixel A.

  On the other hand, the subpixel adjacent to the skeleton subpixel A in the vertical direction is the skeleton-equivalent subpixel D, and “5” is set as the color element level thereof. Then, color element level reference values (reference values defined in the table) are respectively set for a plurality of subpixels adjacent to both sides of the skeleton-corresponding subpixel D.

  Since the skeleton subpixel C is adjacent to the lower side of the skeleton subpixel B, each of the subpixels adjacent to the skeleton subpixel C is assigned to the skeleton subpixel C based on the correction table 53d. In close order, values of “4”, “3”, and “2” are set as reference values as color element levels. For each subpixel located between the skeleton-equivalent subpixel D and the skeleton subpixel C, the color element level reference value set based on the skeleton-equivalent subpixel D and the skeleton subpixel C are used. The color element level is set based on the reference value of the color element level that is set in the above. In this case, the color element level for each subpixel is set to a large color element level by comparing the reference values for each subpixel, and the average or total of the reference values for each subpixel is set as the color element level. A method such as a configuration is applied.

  In FIG. 13C, the color element level “2” is set for the sub-pixels on both sides of the skeleton-corresponding sub-pixel D, and the sub-pixels are arranged on the skeleton sub-pixel C side. Color element levels of “2”, “2”, “3”, and “4” are set for each subpixel. Here, the color element levels on both sides of the skeleton equivalent pixel D are set with reference to a correction pattern table 52d for the skeleton equivalent subpixel as shown in FIG.

  When the skeleton subpixels are adjacent to each other in the horizontal direction, the luminance level of each subpixel located between both skeleton subpixels is flattened by the same process as the flattening process described in the first embodiment. Therefore, the description is omitted. In the following description, only processing for the skeleton-equivalent subpixel will be described.

  When the skeleton-equivalent subpixel is set, it is determined whether there is a skeleton subpixel or a skeleton-equivalent subpixel adjacent to the skeleton-equivalent subpixel in the horizontal direction (step S22). If there is a skeleton subpixel or a skeleton-equivalent subpixel that is paired with the skeleton-equivalent subpixel (Yes), the process proceeds to step S23. If not (No), the process proceeds to step S27.

  In step S22, when there is no skeleton subpixel or skeleton equivalent subpixel that is paired with the skeleton-equivalent subpixel (No), in step S27, for the subpixels laterally adjacent to the skeleton-equivalent subpixel. To set the color element level.

  In contrast, if there is a skeleton subpixel or a skeleton-equivalent subpixel that is paired with the skeleton-equivalent subpixel in step S22 (Yes), the skeleton-equivalent subpixel and the skeleton-equivalent subpixel are paired. The number of subpixels sandwiched between the skeleton subpixel or the skeleton-corresponding subpixel is calculated as the distance between the skeleton-corresponding subpixels (step S23). The specific processing in this case is the same as step S5 in FIG.

  When the distance between the skeleton-equivalent subpixels is calculated in step S23, the skeleton proximity is read out from the skeleton proximity table 53a based on the calculated distance between the skeleton-equivalent subpixels (step S24).

  In FIG. 13C, the color element level of the skeleton-equivalent subpixel is “5”, and the number of subpixels between the skeleton-equivalent subpixel and the skeleton subpixel B is five. From the skeleton proximity table 53a shown in b), “level 2” is obtained as the skeleton proximity.

  When the skeleton proximity is read in step S24, the flattening rate corresponding to the read skeleton proximity is read from the flattening rate table 53b. Then, from all the subpixels positioned between the skeleton-equivalent subpixel pairs, one pixel constituted by each of the R, G, and B subpixels is set as the pixel of interest, and R, G constituting the pixel of interest , B are read from the luminance table 53e for the respective color element levels set for the sub-pixels of B. Then, the read luminance level of each sub-pixel is flattened based on the flattening rate read from the flattening rate table 53b (step S25).

  In FIG. 13C, since the skeleton proximity is “level 2”, “0.5” is read as the flattening rate from the flattening rate table shown in FIG. In FIG. 13C, the R, G, and B subpixels in the target pixel located between the skeleton corresponding subpixel D and the skeleton subpixel C are “2”, “2”, and “3”, respectively. ”, The luminance levels of the R, G, and B sub-pixels are“ 182 ”,“ 182 ”, and“ 146 ”based on the luminance table 53e shown in FIG. . Then, when flattening is performed according to the flattening rate “0.5” read from the flattening rate table illustrated in FIG. 7 and the equations (2-1) to (2-4), R, G, The luminance level of each sub-pixel of B is “177”, “177”, and “159”.

  In this way, when the luminance level of each subpixel of the target pixel located between the skeleton corresponding subpixel D and the skeleton subpixel C is calculated, each calculated luminance level is assigned to each subpixel of the target pixel. It sets for (step S26).

  Next, a voltage corresponding to the luminance level set for each sub-pixel is output to the output unit 4 (step S28).

In step S27, when the color element level is set for the subpixel adjacent in the horizontal direction to the skeleton-equivalent subpixel, the luminance level set for each subpixel is similarly set. After that, the corresponding voltage is output to the output unit 4. Then, it is checked whether or not there is a pixel to be processed. If there is (Yes), the process returns to step S22, and steps S22 to S28 are performed for the pixel to be processed. The process is repeated, and if there is no pixel to be processed (No), the process is terminated.

  As described above, even when the subpixel adjacent in the vertical direction is not a skeleton subpixel, the same processing as that of the skeleton subpixel is performed with the color element level set lower than that of the skeleton subpixel. Thus, characters and the like can be displayed with higher definition.

<Embodiment 3>
The second embodiment described above can also be applied to the case where the strokes constituting the skeleton portions of characters and figures are diagonal lines. In this case, the method disclosed in Japanese Patent Application Laid-Open No. 2005-24987 can be applied to the setting of the skeleton subpixel and the skeleton-equivalent subpixel for displaying diagonal lines on the display screen.

  FIG. 14 is an explanatory diagram in the case where the luminance level between both diagonal lines is flattened when the skeleton part is two diagonal lines. FIG. 14 (a) shows the relationship between the strokes forming two parallel diagonal lines that are the skeleton parts and the sub-pixels on the display screen. The stroke data indicating each stroke is vector data in which the coordinates of the start point and the end point are set. When such stroke data (vector data) of diagonal lines is set on the display screen, the skeleton subpixels and skeleton equivalent subpixels of the diagonal lines are set by the method disclosed in Japanese Patent Application Laid-Open No. 2005-24987. Is done. In this case, first, the sub-pixel through which the stroke passes is specified, and the skeleton sub-pixel and the skeleton are determined based on the distance between the center point of the sub-pixel through which the stroke passes and the point on the stroke having the same X coordinate as the center point. Equivalent subpixels are set.

  When the distance between the center point of a subpixel and a point on the same X coordinate stroke as the center point is smaller than a predetermined value, the subpixel is a skeleton subpixel and has a maximum color element level of “7”. Is set. On the other hand, when the distance between the center point of the subpixel and the point on the same X coordinate stroke as the center point is within a predetermined range larger than the predetermined value, the subpixel corresponds to the skeleton. A color element level (for example, “6”) lower than the color element level set for the skeleton subpixel is set as a subpixel. Furthermore, when there exists a subpixel in which the distance between the center point of the subpixel through which the stroke passes and the point on the stroke of the same X coordinate as the center point is smaller than the predetermined range, the subpixel In addition, a color element level lower than that of the skeleton-equivalent subpixel is set, and, if necessary, other than the skeleton subpixel and the skeleton-equivalent subpixel that are laterally adjacent to the skeleton subpixel and the skeleton-equivalent subpixel. A color element level lower than the color element level set for the skeleton-equivalent subpixel is set for the subpixel.

  As a result, as shown in FIG. 14B, subpixels for displaying two parallel strokes are specified, and a color element level is set for each subpixel.

  When the sub-pixel and the color element level for displaying two parallel strokes are set in this way, the skeleton sub-pixel and the skeleton-equivalent sub are based on the correction table as in the second embodiment. A color element level is set for a sub-pixel adjacent in the horizontal direction with respect to the pixel. As a result, as shown in FIG. 14C, color element levels are set for the subpixels around the skeleton subpixel and the skeleton-equivalent subpixel. Thereafter, in the same manner as in the second embodiment described above, the set color element level is flattened for the sub-pixels of the target pixel located between the skeleton sub-pixels or skeleton-equivalent sub-pixels adjacent in the horizontal direction. Processing is performed.

  As described above, according to this embodiment, the skeleton subpixel adjacent to the skeleton subpixel is also treated in the same manner as the skeleton subpixel, and the skeleton subpixel adjacent to the skeleton equivalent pixel in the horizontal direction. Or, the luminance level of the sub-pixel between the skeleton-equivalent pixels is flattened, so that even if the strokes that make up the characters and figures are close to each other, coloring is applied between the strokes. Can be prevented from occurring. Furthermore, when the strokes are not close to each other, the luminance level of the sub-pixel is not flattened, so that characters, figures, etc. constituted by the strokes can be displayed clearly and clearly.

<Embodiment 4>
In each of the first to third embodiments, the luminance level of the subpixel located in the vicinity of the skeleton subpixel or the skeleton-equivalent subpixel is set according to the length of the skeleton subpixel or the skeleton-equivalent subpixel that is continuous in the predetermined direction. It is also possible to control and set the flattening rate of the luminance level high.

  Usually, when displaying, the coloration generated between the strokes that are close to each other becomes more conspicuous as the portion where the strokes are close to each other is longer. For this reason, when the strokes are adjacent to each other, the number of skeleton subpixels or skeleton-equivalent subpixels constituting the adjacent stroke portions is continuously determined by checking the number of the skeleton subpixels continuously arranged in the vertical direction. As the number of skeleton subpixels or skeleton-equivalent subpixels increases, the portion between adjacent strokes becomes longer. Change to increase the flattening rate.

  In order to change the flattening rate in this way, for example, a flattening reinforcement rate table as shown in FIG. 15 can be used. The flattening reinforcement rate table shown in FIG. 15 includes a stroke length as information indicating that skeleton subpixels or skeleton-equivalent subpixels constituting respective portions of strokes adjacent to each other are continuous in the vertical direction. Information is defined. This “stroke length information” can also be defined by the length of the skeleton subpixels constituting each stroke part adjacent to each other, but in the example of FIG. Thus, it is defined by the ratio of the lengths of adjacent portions (the number of skeleton subpixels or skeleton-equivalent subpixels) in each stroke. And the flattening reinforcement rate which shows the increase rate of the required flattening rate is set with respect to this stroke length information, respectively. The flattening reinforcement rate is set to be larger as the stroke length based on the stroke length information is longer. When the stroke length information is 30% or more and less than 50% of the character height, the flattening reinforcement rate is 50% and the stroke length is the character height. When the thickness is 10% or more and less than 30%, the flattening reinforcement rate is set to 20%, and when the stroke length is less than 10% of the character height / width, the flattening reinforcement rate is set to 0%.

  The reinforced flattening rate x 'can be obtained by the following equation (4) when the flattening rate is x and the flattening reinforcing rate is y%.

x ′ = x + (1−x) × y (4)
For example, when the flattening rate is 0.8, the margin (1-x) for the maximum flattening rate 1 is 0.2. Therefore, if the flattening reinforcement rate is 50%, the reinforced flatness is The conversion rate x ′ is 0.9 (= 0.8 + 0.2 × 50%), and the degree to which the luminance level is flattened increases.

  When the skeletal stroke is represented by vector data as the skeleton part of the skeleton character or figure, when calculating the stroke length information, the difference between the stroke end point coordinates is used as the stroke length for the vertical stroke. The ratio to the overall size of the figure can be obtained. On the other hand, when the stroke length cannot be obtained from the coordinate value because the skeleton stroke is not represented by the vector data, the skeleton subpixels arranged in the vertical direction with respect to the arrangement of the skeleton subpixel or the skeleton-equivalent subpixel. Can be counted and treated as the stroke length.

  In this way, when vertical lines that are close to each other continue for a long time, by increasing the flattening rate of the subpixels between those vertical lines, even when the vertical lines are close to each other for a long time, It is possible to reliably prevent coloring from occurring.

  In each of the above-described embodiments, the method of obtaining the brightness level after flattening by performing calculation every time has been described. However, a table in which the brightness level after flattening is obtained in advance is created and based on the table. By setting the brightness level, it is possible to reduce the calculation cost. In addition, the calculation may be performed each time when the luminance level is flattened with a weight proportional to the brightness through gamma conversion and reverse gamma conversion, but a table in which the calculation results are obtained in advance is prepared. Similarly, it is possible to reduce the calculation cost by setting a value based on the table. In carrying out the present invention, the processing method and configuration can be appropriately selected in consideration of the balance between calculation cost and memory cost for storing as a table.

  As mentioned above, although this invention has been illustrated using preferable embodiment of this invention, this invention should not be limited and limited to this embodiment. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention. Patents, patent applications, and references cited herein should be incorporated by reference in their entirety as if the contents themselves were specifically described herein. Understood.

  The present invention is set to correspond to a skeleton part such as a character and a figure and a part corresponding to the skeleton in an electronic device or an information device provided with a display device or a printing device such as a personal computer, a mobile phone, a digital television. The luminance level of the sub-pixel sandwiched between the skeleton sub-pixel and the skeleton-corresponding sub-pixel is controlled to be flattened. As a result, even when strokes constituting characters, figures, etc. are close to each other, there is no possibility of coloring between strokes, and adjacent strokes are displayed in close contact with each other. Therefore, it is possible to suppress the characters and the like from being crushed and displayed. Further, when adjacent strokes are not close to each other, the outline of each stroke can be clearly displayed, and as a result, characters, figures, and the like can be clearly displayed.

Claims (10)

An image information generation device that generates image information of characters or figures for output to a display device,
The display device includes a plurality of pixels, each of the plurality of pixels including a plurality of sub-pixels arranged in a predetermined first direction, and the plurality of sub-pixels include a plurality of different color elements. Is assigned,
The image information generation device includes:
Skeleton subpixel setting means for setting at least one subpixel corresponding to the skeleton portion of the character or figure as at least one skeleton subpixel;
Color element level setting means for setting a color element level for each of the skeleton subpixel and at least one subpixel adjacent to the skeleton subpixel along the predetermined first direction;
Determining means for determining whether there are two skeleton subpixels adjacent to each other along the predetermined first direction;
Calculating means for calculating a distance between the two skeleton subpixels when it is determined that there are two skeleton subpixels adjacent to each other along the predetermined first direction;
A flattening rate setting means for setting a flattening rate for flattening a luminance level corresponding to the color element level of a plurality of subpixels positioned between the two skeleton subpixels based on the calculated distance; ,
An image information generating apparatus comprising: flattening means for flattening a luminance level of the plurality of subpixels positioned between the two skeleton subpixels based on the set flattening rate.   The R (red), G (green), and B (blue) are respectively assigned as color elements to the plurality of subpixels included in a single pixel in the display device. Image information generation device.   The image information generating apparatus according to claim 1, wherein the flattening rate setting unit sets the flattening rate for each of a plurality of subpixels included in a pixel of interest located between the two skeleton subpixels. .   The image information generating apparatus according to claim 1, wherein the flattening rate setting unit sets the flattening rate so that the flattening rate increases as the distance between the two skeleton subpixels decreases.   In the case where there are at least two skeleton subpixels continuous along a predetermined second direction orthogonal to the predetermined first direction, the flattening rate setting means is arranged to perform the predetermined second direction. The image information generating apparatus according to claim 1, wherein the flattening rate is set so that the flattening rate becomes higher as the number of continuous skeleton subpixels increases. The color element level setting means sets a maximum color element level for the skeleton subpixel,
When there is a subpixel that is adjacent to the skeleton subpixel along the predetermined second direction and is not the skeleton subpixel, the color element level setting unit sets the subpixel to the skeleton. As the equivalent subpixel, a color element level smaller than the maximum color element level is set for the skeleton equivalent subpixel,
The image information generation apparatus according to claim 1, wherein the calculation unit processes the skeleton-equivalent subpixel in the same manner as the skeleton subpixel. When the stroke constituting the skeleton portion is an oblique line, at least one skeleton subpixel and at least one skeleton-equivalent subpixel are specified for the oblique line;
The color element level setting means sets a maximum color element level for the skeleton subpixel,
The color element level setting means sets a color element level smaller than the maximum color element level for the skeleton-equivalent subpixel,
The image information generation apparatus according to claim 1, wherein the calculation unit processes the skeleton-equivalent subpixel in the same manner as the skeleton subpixel. An image information generation method for generating image information of characters or figures for output to a display device,
The display device includes a plurality of pixels, each of the plurality of pixels including a plurality of sub-pixels arranged in a predetermined first direction, and the plurality of sub-pixels include a plurality of different color elements. Is assigned,
The image information generation method includes:
Setting at least one subpixel corresponding to the skeleton portion of the character or figure as at least one skeleton subpixel;
Setting a color element level for each of the skeleton subpixel and at least one subpixel adjacent to the skeleton subpixel along the predetermined first direction;
Determining whether there are two skeletal subpixels adjacent to each other along the predetermined first direction;
If it is determined that there are two skeleton subpixels adjacent to each other along the predetermined first direction, calculating a distance between the two skeleton subpixels;
Setting a flattening rate for flattening a luminance level corresponding to a color element level of a plurality of subpixels located between the two skeleton subpixels based on the calculated distance;
Flattening brightness levels of the plurality of sub-pixels positioned between the two skeleton sub-pixels based on the set flattening rate.   An image information generation program for causing a computer to execute each step of the image information generation method according to claim 8.   A computer-readable recording medium on which the image information generating program according to claim 9 is recorded.

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