JP2006050071A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can use an output gamma regulated to match an outputting method and can obtain an output result with good density in various outputs. <P>SOLUTION: The image forming apparatus includes a color space converting means for converting to an output color space, an output density regulating means which can regulate the output density by the output gamma, and a dither processing means for performing dither processing for expressing an intermediate color. An arbitrary output gamma can be designated for the output density regulating means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention performs image formation at a density suitable for monochrome and color by switching output gamma between monochrome output and color output, and enables monochrome output by using color output gamma for monochrome output. The present invention relates to an image forming apparatus having means for eliminating a density difference from an output color output.

In an image forming apparatus, density adjustment is performed by applying an output gamma before performing dither processing for expressing halftones. (Patent Document 1) With regard to this density adjustment, in a certain image forming apparatus, when monochrome output is specified, the output gamma is adjusted with respect to a light color such as yellow, so that, for example, the density of a yellow character or the like is reduced to a level that can be clearly read by the user. It is output after raising. When color output is specified, this density adjustment is not performed, so the output gamma used differs between color output specification and monochrome output specification. The monochrome monochrome drawing object and monochrome output specification when color output is specified In the same drawing object at the time, the density was output differently. There are also image forming devices that can obtain output results with the same density regardless of color or monochrome by using the same output gamma when specifying color output and when specifying monochrome output. Etc. were very thin and difficult to read.
Japanese Patent Laid-Open No. 08-331398

  As described above, it is possible to improve the output result when monochrome output is specified by using different output gamma when specifying color output and monochrome output. The same drawing object is output at different densities when specified, and when the color output is specified and monochrome output is specified, the same output gamma is used to output the drawing object at the same density regardless of the output specification. The following describes how to solve the problem of drawing objects that are difficult to see when specified.

  The invention according to claim 1 is characterized in that an arbitrary output gamma can be designated for the output density adjusting means. As a result, an output gamma adjusted according to the output method can be used, and it is possible to obtain output results with good density at various outputs.

  The invention according to claim 2 is characterized in that the output gamma is different when color output is designated and when monochrome output is designated. This makes it possible to use an output gamma suitable for color output when specifying color output, and to use an output gamma suitable for monochrome output when specifying monochrome output. It becomes possible.

  The invention according to claim 3 is characterized in that the output gamma designated at the time of monochrome output designation can be designated by switching between the output gamma for monochrome output and the output gamma for color output. By setting the output gamma for color output when monochrome output is designated, the density of the same drawing object can be made the same regardless of whether it is color output or monochrome output. In addition, by setting the output gamma for monochrome output when monochrome output is designated, output with a density suitable for monochrome output is possible. By making these switchable, an output result suitable for the purpose can be obtained.

  The invention according to claim 4 is characterized in that the user can designate an output gamma designated at the time of monochrome output designation through the UI. Thereby, the user himself / herself can determine the density selection desired by the user.

(Example 1)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a data processing flow of the image forming apparatus according to the first exemplary embodiment.

  In the figure, reference numeral 101 denotes a drawing command analysis unit 102 that analyzes a drawing command, a renderer 103 that generates a raster image from the drawing command, a color space conversion unit 104 that performs color space conversion, and a density adjustment of an output image. The image forming apparatus includes an output gamma unit 105 and a dithering unit 106 that performs halftone processing. Further, the output gamma unit 105 can designate and process the output gamma A and the output gamma B.

  In this embodiment, a procedure from generation of a drawing command to generation of output data will be described with reference to the flowchart of FIG. S201 to S205 show each step.

  In step S201, the drawing command is analyzed, and the process proceeds to step S202.

  In step S202, rendering is performed, and the process proceeds to step S203.

  In step S203, the output gamma designated by the drawing command is stored in the memory, and the process proceeds to step S204.

  In step S204, the output gamma is read from the memory, the density is adjusted, and the process proceeds to step S205.

  In step S205, halftone processing is performed and the process ends.

(Example 2)
FIG. 3 is a diagram illustrating a data processing flow of the image forming apparatus according to the second embodiment.

  In the figure, reference numeral 301 denotes a drawing command analysis unit 302 that analyzes a drawing command, a renderer 303 that generates a raster image from the drawing command, a color space conversion unit 304 that performs color space conversion, and a density adjustment of an output image. The image forming apparatus includes an output gamma unit 305 and a dithering unit 306 that performs halftone processing. Further, the color space conversion unit 304 can switch the color space conversion processing method according to the designation from the output designation setting unit 307, and the output gamma used by the output gamma unit 305 is output by the output gamma selection unit 308. Using the signal from the designation unit 307, it is determined and designated whether to use the output gamma for color output or the output gamma for monochrome output.

  In this embodiment, a procedure from generation of a drawing command to generation of output data will be described with reference to the flowchart of FIG. S401 to S408 show each step.

  In step S401, the drawing command is analyzed, and the process proceeds to step S402.

  In step S402, rendering is performed, and the process proceeds to step S403.

  In step S403, it is determined whether the output designation is a color output designation. If the output designation is a color output designation, the process proceeds to step S404.

  In step S404, CMYK color space conversion is performed, and the process proceeds to step S405.

  In step S405, density adjustment is performed using the output gamma for color output, and the process proceeds to step S408.

  On the other hand, if the monochrome output is designated in step S403, the process proceeds to step S406.

  In step S406, K monochrome color space conversion is performed, and the process proceeds to step S407.

  In step S407, density adjustment is performed using the output gamma for monochrome output, and the process proceeds to step S408.

  In step S408, halftone processing is performed and the process ends.

(Example 3)
FIG. 5 is a diagram illustrating a data processing flow of the image forming apparatus according to the third embodiment.

  In the figure, reference numeral 501 denotes a drawing command analysis unit 502 that analyzes a drawing command, a renderer 503 that generates a raster image from the drawing command, a color space conversion unit 504 that performs color space conversion, and a density adjustment of an output image. The image forming apparatus includes an output gamma unit 505 and a dithering unit 506 that performs halftone processing. Further, the color space conversion unit 504 can switch the color space conversion processing method according to the designation from the output designation setting unit 507, and the output gamma used by the output gamma unit 505 is output by the output gamma selection unit 508. Using the signal from the designation unit 507 and the signal from the drawing command analysis unit 502, it is determined and designated whether to use the output gamma for color output or the output gamma for monochrome output.

  In this embodiment, a procedure from generation of a drawing command to generation of output data will be described with reference to the flowchart of FIG. S601 to S610 indicate each step.

  In step S601, the drawing command is analyzed, and the process proceeds to step S602.

  In step S602, rendering is performed, and the process proceeds to step S603.

  In step S603, it is determined whether the output designation is a color output designation. If the output designation is a color output designation, the process proceeds to step S604.

  In step S604, CMYK color space conversion is performed, and the flow advances to step S605.

  In step S605, density adjustment is performed using the output gamma for color output, and the process proceeds to step S610.

  On the other hand, if the monochrome output is designated in step S603, the process proceeds to step S606.

  In step S606, K monochrome color space conversion is performed, and the process proceeds to step S607.

  In step S607, it is determined whether or not color output output gamma is designated. If color output output gamma is designated, the process advances to step S608.

  In step S608, density adjustment is performed using the output gamma for color output, and the process proceeds to step S610.

  On the other hand, if the output gamma for monochrome output is designated in step S607, the process proceeds to step S609.

  In step S609, density adjustment is performed using the output gamma for monochrome output, and the process proceeds to step S610.

  In step S610, halftone processing is performed and the process ends.

(Example 4)
FIG. 7 is a diagram illustrating a data processing flow of the image forming apparatus according to the fourth embodiment.

  In the figure, reference numeral 701 denotes a drawing command analysis unit 702 that analyzes a drawing command, a renderer 703 that generates a raster image from the drawing command, a color space conversion unit 704 that performs color space conversion, and a density adjustment of an output image. The image forming apparatus includes an output gamma unit 705, a dithering unit 706 that performs halftone processing, and a UI 709. Reference numeral 709 denotes a UI including a UI for designating color output or monochrome output and a UI for designating color output output gamma or monochrome output output gamma. The color space conversion unit 704 can switch the color space conversion processing method according to the designation from the output designation setting unit 707, and this output designation is set by a signal from the UI 710 that designates color output or monochrome output. The output gamma used in the output gamma unit 705 is selected and designated by the output gamma selection unit 708, and this output gamma setting designates the signal from the output designation unit 707 and the output gamma for color output or the output gamma for monochrome output. To be selected from the signal from the UI 711.

  In this embodiment, a procedure from generation of a drawing command to generation of output data will be described with reference to the flowchart of FIG. S801 to S810 indicate each step.

  In step S801, the drawing command is analyzed, and the process proceeds to step S802.

  In step S802, rendering is performed, and the process proceeds to step S803.

  In step S803, it is determined whether the output designation is a color output designation. If the output designation is a color output designation, the process proceeds to step S804.

  In step S804, CMYK color space conversion is performed, and the flow advances to step S805.

  In step S805, density adjustment is performed using the output gamma for color output, and the process proceeds to step S810.

  On the other hand, if the monochrome output is designated in step S803, the process proceeds to step S806.

  In step S806, K monochrome color space conversion is performed, and the process proceeds to step S807.

  In step S807, it is determined whether or not the color output output gamma is designated. If the color output output gamma is designated, the process proceeds to step S808.

  In step S808, density adjustment is performed using the output gamma for color output, and the process proceeds to step S810.

  On the other hand, if the output gamma for monochrome output is designated in step S807, the process proceeds to step S809.

  In step S809, density adjustment is performed using the output gamma for monochrome output, and the process proceeds to step S810.

  In step S810, halftone processing is performed and the process ends.

FIG. 3 is a diagram illustrating a data processing flow of the image forming apparatus according to the first exemplary embodiment. 3 is a flowchart illustrating a data processing procedure in the first embodiment. FIG. 10 is a diagram illustrating a data processing flow of the image forming apparatus according to the second exemplary embodiment. 10 is a flowchart illustrating a data processing procedure in the second embodiment. FIG. 10 is a diagram illustrating a data processing flow of the image forming apparatus according to the third exemplary embodiment. 10 is a flowchart illustrating a data processing procedure in the third embodiment. FIG. 10 is a diagram illustrating a data processing flow of the image forming apparatus according to the fourth exemplary embodiment. 14 is a flowchart illustrating a data processing procedure in the fourth embodiment.

Claims (4)

  A color space converting means for converting to an output color space; an output density adjusting means capable of adjusting an output density by output gamma; and a dither processing means for performing a dither process for expressing an intermediate color. An image forming apparatus characterized in that an arbitrary output gamma can be designated.   2. The printing apparatus according to claim 1, wherein the output gamma is different when color output is specified and when monochrome output is specified.   3. The printing apparatus according to claim 2, wherein an output gamma designated when monochrome output is designated can be switched between an output gamma for monochrome output and an output gamma for color output.   4. The printing apparatus according to claim 3, wherein an output gamma designated when monochrome output is designated can be designated by a user through a UI.

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