JP2001053978A - Color image processing equipment - Google Patents

Abstract

(57) [Summary] [Problem] To provide a color image processing apparatus capable of processing and reproducing line information without losing line information by fine line processing. An external connection unit receives image information related to printing from an external device, and stores the information in a storage unit (step S11). When the image information is stored in the storage unit 3, if the information to be processed is the information of the graphic processing (step S12), the graphic processing unit 9
Indicates whether the information is the information of the line drawing process (step S
12A) Whether the information is for the filling process (step S12)
B), and in the case of the information of the line drawing processing, the graphic density correction unit 10 converts the low density color information to a reproducible density (high density) (step S16). A drawing process is performed (step S17).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus such as a color laser printer, and more particularly, to a color image processing apparatus capable of processing and reproducing graphic drawing, in particular, fine line processing without losing line information. .

[0002]

2. Description of the Related Art It is difficult to reproduce 256 gradations with one pixel in a printer such as a normal color laser printer. In order to reproduce this, normally, halftone processing such as dither processing of nxm pixels is performed to obtain a gradation.

[0003]

However, according to the conventional color image processing apparatus, due to the gradation processing, not only a line having a thickness (length) less than a dither pattern cannot accurately represent a color, There was a problem that it was not drawn at all. This tendency is more pronounced for thin lines, low densities, and dotted lines and broken lines. This problem is serious in applications that make heavy use of fine lines, especially in CAD and the like.

Accordingly, it is an object of the present invention to provide a color image processing apparatus capable of processing and reproducing line information without losing line information by fine line processing.

[0005]

According to the present invention, in order to achieve the above object, when image information received from an external device is graphic information, graphic processing means for processing the graphic information, Graphic density correcting means for correcting the density of the graphic information, wherein when the density of the graphic information to be processed is low density, the graphic density correcting The color image processing apparatus is characterized in that the density is corrected to a reproducible density.

In the above arrangement, the color image processing apparatus further includes a line thickness detecting means for detecting a line thickness and a line length, and the line detected by the line thickness detecting means can be reproduced. It is preferable that the correction by the graphic density correction means is performed on the line only when the width and length have not been reached.

Further, the color image processing apparatus further comprises:
It is preferable that the image processing apparatus further includes a color / monochrome conversion unit for converting color information into black / white luminance information, and performs the correction by the graphic density correction unit on the luminance information converted by the color / black / white conversion unit.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described in detail.

FIG. 1 shows a first embodiment of the present invention.
FIG. 3 is a block diagram of a main part of the color image processing apparatus according to the embodiment. In the figure, reference numeral 11 indicates the entire color image processing apparatus. As shown in the figure, the color image processing apparatus 11 includes a CPU 1, a ROM / RAM 2, a storage unit 3, a writing unit 4, an external connection unit 5, an image processing unit 6, a character processing unit 7, It is composed of an image processing unit 8, a graphic processing unit 9, and a graphic density correction unit 10, and the components are interconnected via a common bus 20.

In the above arrangement, image information to be printed and information on condition settings such as paper size are sent from an external device 12 such as a personal computer. The color image processing apparatus 11 receives information from the external device 12 through the external connection unit 5 serving as an interface and stores the information at a predetermined position in the storage unit 3.

The image information from the external device 12 stored in the storage unit 3 is processed by the image processing unit 6 into a form desired to be printed for each page, and stored in the storage unit 3 again. In the case of a color image, information is processed and stored for each of cyan, magenta, and yellow (black). Here, the image processing unit 6 performs, for each piece of information to be processed, for example, the character processing unit 7 for character processing, and the image processing unit 8 for image processing.
In the case of graphic processing, the graphic processing unit 9
, Respectively.

FIG. 2 is a diagram for explaining the operation of the color image processing apparatus according to the first embodiment. Here, the operation of performing graphic processing by converting low-density color information to a reproducible density by thin line processing is described. First, the external connection unit 5 receives image information on printing from the external device 12, and stores the information in the storage unit 3 (step S11). When the image information is stored in the storage section 3, the image processing section 6 performs information processing for each piece of information to be processed, for example, if the information is character processing information (step S13), in the character processing section 7 (step S19). ), If it is information on image processing (step S14), the image processing unit 8
In step S20, if it is print control information (step S15), print control processing is performed (step S21). On the other hand, if the information is graphic processing information (step S12), the graphic processing unit 9 determines whether the information is information on line drawing processing (step S12A) or information on filling processing (step S1).
2B), and in the case of the information of the line drawing process,
The graphic density correction unit 10 converts the low density color information to a reproducible density (high density) (step S16) and performs a line drawing process (step S1).
7). In the case of the information on the filling process, the graphic processing unit 9 executes the filling process (step S1).
8).

As described above, according to the present embodiment, since the graphic density correction is performed by the graphic processing unit, it is possible to process and reproduce the fine line processing without losing the line information.

[Second Embodiment] FIG. 3 shows a second embodiment of the present invention.
FIG. 3 is a block diagram of a main part of the color image processing apparatus according to the embodiment. Although the same reference numerals are given to the same contents as those in FIG. 1, duplicate description will be omitted, but in this embodiment,
It is characterized in that it further has a line-thickness detection unit 13 in addition to the configuration of FIG. Paying attention to the problem to be solved is a problem peculiar to a thin line, the reproducibility is given priority over the gradation characteristic of only the thin line by the thickness and length detecting function.

FIG. 4 is a diagram for explaining the operation of the color image processing apparatus according to the second embodiment. Here, the operation of converting graphic information of low density to reproducible density when the line does not reach the width and length in which the color can be reproduced in the thin line processing is described. First,
The external connection unit 5 receives the image information on the print from the external device 12, and stores the information in the storage unit 3 (Step S31). When the image information is stored in the storage unit 3,
For each piece of information to be processed, for example, if the information is character processing information (step S33), the image processing unit 6 performs information processing in the character processing unit 7 (step S40), and if the information is image processing information (step S34). 3.) Information processing is performed by the image processing unit 8 (step S41), and if it is information of print control (step S35), print control processing is performed (step S42). On the other hand, if the information is graphic processing information (step S32), the graphic processing unit 9
Whether the information is information of the line drawing process (step S32
A) Whether the information is the filling processing (step S32B)
And in the case of the information of the line drawing process, the graphic processing unit 9 determines whether or not the line to be processed by the line thickness detecting unit 13 has a width and a length capable of color reproduction (step S36). Only when the width and length have not reached the reproducible color, the graphic density correction unit 10 converts the low-density color information until the reproducible density (high density) is reached (step S37). Perform (Step S3
8). In the case of the information on the filling process, the graphic processing unit 9 executes the filling process (step S3).
9).

As described above, according to the present embodiment, the graphic processing section performs graphic density correction only on thin lines having poor reproducibility, so that color reproducibility of thick (long) lines is not adversely affected. Processing and reproduction can be performed without losing line information by fine line processing.

[Third Embodiment] FIG. 5 shows a third embodiment of the present invention.
FIG. 3 is a block diagram of a main part of the color image processing apparatus according to the embodiment. Although the same reference numerals are given to the same contents as those in FIG. 1, duplicate description will be omitted, but in this embodiment,
In addition to the configuration of FIG.
Is characterized by having This is to apply to a monochrome print mode of a color image.

FIG. 6 is a diagram for explaining the operation of the color image processing apparatus according to the third embodiment. Here, an operation is described in which color information is converted into luminance information and low-density color information is converted to a reproducible density and graphic processing is performed in thin line processing when the monochrome print mode is set. First, the external connection unit 5 receives image information on printing from the external device 12, and stores the information in the storage unit 3 (step S51). When the image information is stored in the storage unit 3, the image processing unit 6
For example, if it is character processing information (step S5
3) After conversion into gray information in the color / monochrome conversion unit 14 (step S58), information processing is performed in the character processing unit 7 (step S64). After conversion into gray information (step S59), information processing is performed by the image processing unit 8 (step S65). If the information is print control information (step S55), print control processing is performed (step S67). On the other hand, if it is a graphic processing (step S52), the graphic processing unit 9
Indicates whether the information is the information of the line drawing process (step S
52A) Whether the information is for the filling process (step S52)
B), and in the case of the information of the line drawing processing, the color / monochrome conversion unit 14 converts the information into gray information (step S56). If the line thickness detection unit 13 is provided, the line to be processed is processed. Is determined to be a width and a length in which color can be reproduced (step S61), and only when the width and the length in which the color can be reproduced have not been reached (determination in step S61: YES), The color information is converted to a reproducible density (step S62), and a line drawing process is performed (step S63). In the case of the information of the filling process, the graphic processing unit 9 executes the filling process after converting the information into gray information in the color / monochrome conversion unit 14 (step S57) (step S64).

As described above, according to the present embodiment, since the graphic information is subjected to the graphic density correction by the gray information which has been subjected to the color / monochrome conversion, it is possible to process and reproduce the thin line processing without losing the line information. Can be.

[0020]

As described above, according to the color image processing apparatus of the present invention, when the image information received from the external device is graphic information, the graphic processing means for processing the graphic information, Graphic density correction means for performing density correction, wherein the graphic processing means can reproduce low density color information by the graphic density correction means when the density of the graphic information to be processed is low density. Since the correction is performed up to the density, the line information can be processed and reproduced without losing the line information in the thin line processing.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main part of a color image processing apparatus according to a first embodiment.

FIG. 2 is a diagram for explaining an operation of the color image processing apparatus according to the first embodiment.

FIG. 3 is a block diagram of a main part of a color image processing apparatus according to a second embodiment.

FIG. 4 is a diagram for explaining an operation of the color image processing apparatus according to the second embodiment.

FIG. 5 is a block diagram of a main part of a color image processing apparatus according to a third embodiment.

FIG. 6 is a diagram for explaining an operation of the color image processing apparatus according to the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 2 ROM / RAM 3 Storage part 4 Writing part 5 External connection part 6 Image processing part 7 Character processing part 8 Image processing part 9 External connection part 10 Graphic density correction part 11 Color image processing device 12 External device 13 Color black and white conversion part 14 thick detector 20 bus

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2C262 AA05 AA24 AB13 BA09 BA16 BC07 CA09 DA01 EA13 5B021 AA01 LG07 LG08 5B057 CA01 CA08 CA11 CB01 CB08 CB11 CC03 CE11 CE18 CF02 5C077 LL08 MP08 PP15 PP31 PP33 PP38 PP43 LA10 LA12 LB15 NA02 PA03

Claims (3)

[Claims] 1. An image processing apparatus comprising: graphic processing means for processing graphic information when image information received from an external device is graphic information; and graphic density correcting means for correcting density of the graphic information. Wherein the graphic processing means corrects the low density color information to a reproducible density by the graphic density correction means when the density of the graphic information to be processed is low density. apparatus. 2. The color image processing apparatus according to claim 1, further comprising a line width detecting unit for detecting a line thickness and a line length, wherein the line width detected by the line width detecting unit is reproducible. 2. The color image processing apparatus according to claim 1, wherein the correction by the graphic density correction unit is performed on the line only when the line has not reached the threshold. 3. The color image processing apparatus further comprises a color / monochrome conversion means for converting color information into black / white luminance information, and the graphic density correction for the luminance information converted by the color / monochrome conversion means. 3. The color image processing apparatus according to claim 1, wherein the correction is performed by means.