JP2001171186A - Method and system for processing image for printing data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a system for processing images for printing data which include a density correction process with an environment condition taken into account to obtain good printing output images. SOLUTION: A host computer 100 requests a printer apparatus 200 to transmit environment condition information before processing images to obtain printing data. The printer apparatus 200 detects the environment condition information in response to the request and sends the information back to the host computer 100. The host computer 100 corrects a density of printing data based on the environment condition information when processing images. The host computer 100 sends printing data after the density is corrected to the printer apparatus 200.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method and system for printing image data, and more particularly, to a printing system including a host computer and a printer connected by two-way communication. The present invention relates to a print data image processing method and system for performing density correction in a host computer based on environmental conditions.

[0002]

2. Description of the Related Art In a printer such as an ink jet printer or a laser printer, density correction processing of print data for various factors is performed in order to improve the quality of a print output image. One of such factors is a difference in print media. For example, in the case of an inkjet printer, a printing method such as an ink discharge amount and a printing process is changed according to a difference in paper type such as plain paper, recycled paper, coated paper, and OHP sheet, or a type of paper brand. Things are needed. It is also necessary to consider such factors at the stage of generating print data on the host computer.

A printer driver generates print data on a host computer. In this printer driver, setting items of paper type are provided, and plain paper,
Paper settings are made for each paper type, such as reproduction, coated paper, and OHP sheets.

[0004]

By the way, the characteristics of the print medium, such as ink permeability, change with environmental changes such as temperature and humidity. In a printer device, a process of correcting the output characteristics of a head is performed according to a head temperature or the like. In a printer driver on a host computer that generates print data, a correction process (for example, temperature And correction of the influence of the paper properties due to humidity and humidity) were not performed, and there were cases where sufficient correction could not be performed only by the output characteristic correction on the printer device side.

The present invention has been made in view of such a conventional situation, and has as its object to print data for a print data including a density correction process in consideration of environmental conditions in order to obtain a good print output image. An object of the present invention is to provide an image processing method and system.

[0006]

An image processing method for print data according to the present invention performs image processing by a host computer to obtain print data, transfers the print data to a printer, and causes the printer to process the print data. An image processing method for print data on a host computer in a system for performing printing, wherein the host computer requests transmission of environmental condition information to a printer device prior to image processing for obtaining print data; and Receiving the transmitted environmental condition information;
Obtaining print data by performing image processing,
In the image processing, density correction of print data is performed based on the environmental condition information. This makes it possible for the host computer to grasp the environmental conditions in the printer device and perform density correction suitable for the environmental conditions.

The present invention can also be understood as a recording medium storing a computer program for performing the print data image processing method.

The present invention can be understood as a system. The system performs image processing on a host computer to obtain print data, transfers the print data to a printer, and prints the print data on the printer. In the system, the host computer, prior to image processing for obtaining print data, means for requesting transmission of environmental condition information to the printer device, means for receiving the environmental condition information transmitted from the printer device, Means for obtaining print data by performing image processing, means for transmitting print data to a printer device, and means for performing density correction of print data based on the environmental condition information at the time of the image processing, the printer device comprising: Means for detecting environmental condition information in response to a request for transmission of environmental condition information from a host computer; To a means for transmitting the environmental condition information to the host computer, means for receiving print data from a host computer, comprising the means for printing the print data received. Here, the means for performing the density correction converts, for example, an input density value into an output density value in a predetermined relationship based on the environmental condition information.

[0009]

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

FIG. 1 is a block diagram showing a printing system to which an image processing method according to an embodiment of the present invention is applied, which comprises a host computer and a printer connected by a bidirectional communication line.

This printing system comprises a host computer 100, a printer 200, and a communication line 300 connecting them.

The host computer 100 includes an input unit 10
1, a display unit 102, an input / output data control unit 103,
The interface control unit 104 and the print data control unit 10
5, an image processing unit 106, a storage unit 107, a recording medium reading unit 108, a central processing unit (CPU) 109 for controlling the entire operation of the host computer 100, and a system bus 110 for connecting these. ing.

The input unit 101 is a pointing device such as a keyboard and a mouse. The display unit 102 is a CRT
Display, liquid crystal display and the like. The print data control unit 105 is a so-called printer driver. The image processing unit 106 performs image processing on data generated by an application or the like between the printer 200 and an operating system resident on the host computer 100. To generate print data according to the printer and to control the printer 200.
08 is stored on a recording medium to be read. The recording medium reading unit 108 includes an FD (flexible disk),
A program such as a printer driver and image data recorded on a recording medium such as a CD-ROM, a ROM, and a magnetic tape can be read. The storage unit 107 also stores a density correction table group 111 described later.

The printer device 200 includes an engine unit 201.
, A controller unit 202, and a storage unit 203 controlled by the controller unit 202.

The engine unit 201 includes a temperature sensor 204 and a humidity sensor 2 in addition to normal engine processing such as print output.
A function of detecting environmental condition information by a sensor such as 05 and notifying the controller unit 202 of the environmental condition request in a timely manner. The controller unit 202 controls the entire operation of the printer 200 in addition to the normal output control. In particular,
Recognize the environmental condition request from the host computer 100 and notify the engine unit 201 of the request.
1 transmits the environmental condition information returned from host computer 1
Control to send to 00 is performed. The storage unit 203 is controlled by the controller unit 202, and controls the host computer 1
The print data received from 00 is stored.

The communication line 300 may be a bidirectional parallel interface such as IEEE1284 or a bidirectional serial interface such as IEEE1394 and USB (Universal Serial Bus).

FIG. 2 is a schematic flowchart showing an example of conventional image processing performed by a host computer to which the present invention is applied. This indicates image processing for converting display RGB image data into CMYK image data corresponding to four color (cyan C, magenta M, yellow Y, and black K) inks.

More specifically, CMY image data is obtained by subjecting the RGB image data input in step S101 to luminance / density conversion in step S102. The three primary color inks of cyan, magenta, and yellow are not ideal colors and have other unnecessary color components. To reduce the influence of the unnecessary components, the C
The MY image data is subjected to color correction by a masking method or the like.

The color-corrected CMY image data is converted into CMYK image data by a black generation process in step S104. Generally, the minimum value of the C, M, and Y image data is replaced with black image data K as an achromatic component (black generation), and the value of K is subtracted from each of the original C, M, and Y image data (under color removal). ) To obtain CMYK image data. Thereafter, in step S105, density correction is performed in consideration of the paper type and the like, and output data obtained by performing output correction in step S106 is sent to the printer device 200.

FIG. 3 is a schematic flowchart showing an example of image processing according to the present invention in which a new step is added to the image processing of FIG.

The print data control unit 105 (printer driver) on the host computer 100 transmits an environmental condition request to the printer 200 in step S111 prior to image processing. Upon receiving the environmental condition request in step S112, the printer device 200 detects an environmental condition (for example, temperature or humidity), and transmits the detected environmental condition information to the print data control unit 105 in step S113. In step S114, the print data generation unit 200 on the host computer 100 selects an appropriate density correction table (or parameter conversion formula, etc.) from the table group 111 (see FIG. 1) based on the information obtained by the environmental condition request. ). Note that the density correction table 111 corresponding to the environmental condition information is prepared in advance. The format in which the information obtained from the environmental condition request is reflected in the density correction is determined empirically or experimentally. The format of the correction data may be a table, a parameter conversion formula, or another format.

From step S115, the conventional C
Image processing for converting the display RGB image data of the RT display into CMYK image data corresponding to four color (cyan C, magenta M, yellow Y, and black K) inks is performed.
That is, CMY image data is obtained by subjecting the RGB image data input in step S115 to luminance / density conversion in step S116. In step S117,
A color correction such as a masking method is performed on the CMY image data.
The color-corrected CMY image data is stored in step S
The image is converted into CMYK image data by the black generation processing of 118. Thereafter, in step S119, density correction is performed using the density correction table selected in step S114, and output data obtained by performing output correction in step S120 is sent to the printer device 200.

FIG. 4 is a diagram showing an example of the table group 111 to be selected in step S114. Here, four tables are shown. The upper row of each table shows the value of the table reference index (that is, the input density),
The lower row shows the corresponding output density value. Table 1 is a table used when the temperature is, for example, 15 ° C. to 20 ° C. As can be seen from the drawing, this table 1 is a non-conversion table in which the input density value is used as it is as the output density value. Table 2 is a table used when the temperature is lower than 15 ° C. In Table 2, conversion is performed to raise (increase) a corresponding output density value in a region where the input density value is high. Table 3 is for temperatures between 20 ° C and 25
This is a table used when ゜ C. This table 3
Performs a conversion to reduce the input density value over the whole. Table 4 is a table used when the temperature is 25 ° C. or higher. This table 4 is for performing a correction for further reducing the input density value. Here, a table corresponding to only the temperature as the environmental condition is shown, but a table group corresponding to the humidity instead of the temperature or a table group corresponding to the combination of the temperature and the humidity may be provided.

Although the preferred embodiment of the present invention has been described above, various modifications and changes are possible. For example,
The number of tables in FIG. 4, the boundary value of the temperature, and the value of the output density are merely examples, and the present invention is not limited thereto.

[0025]

According to the present invention, density correction processing can be performed in the host computer in consideration of the environmental conditions of the printer device, and a good print output image can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a printing system according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an example of conventional image processing.

FIG. 3 is a schematic flowchart illustrating an example of image processing according to the present invention in which a new step is added to the image processing of FIG. 2;

FIG. 4 is a diagram illustrating an example of a correction table group according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 host computer 107 storage unit 108 recording medium reading unit 109 central processing unit (CPU) 111 density correction table group 200 printer device 204 temperature sensor 205 humidity sensor 300 communication line

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Claims (4)

[Claims] An image processing method for print data on a host computer in a system in which a host computer performs image processing to obtain print data, transfers the print data to a printer, and prints the print data with the printer. Requesting the printer device to transmit environmental condition information before the host computer performs image processing for obtaining print data; receiving the environmental condition information transmitted from the printer device; And obtaining print data by performing the image processing. The image processing method for print data, wherein, in the image processing, the density correction of the print data is performed based on the environmental condition information. 2. A print data image processing method on a host computer in a system in which a host computer performs image processing to obtain print data, transfers the print data to a printer device, and prints the print data with the printer device. The host computer requests transmission of environmental condition information to a printer device prior to image processing for obtaining print data; and Receiving the environmental condition information, and performing print processing by performing image processing. A recording medium storing a computer program for performing density correction of print data based on the environmental condition information during the image processing. . 3. A system in which image processing is performed by a host computer to obtain print data, the print data is transferred to a printer device, and the print data is printed by the printer device. Means for requesting the printer device to transmit environmental condition information prior to image processing for obtaining; means for receiving environmental condition information transmitted from the printer device; means for performing image processing to obtain print data; Means for transmitting print data to a printer, and means for performing density correction of the print data based on the environmental condition information at the time of the image processing, wherein the printer transmits a request for transmission of environmental condition information from a host computer. Means for detecting the environmental condition information, and means for transmitting the detected environmental condition information to the host computer. When the image processing system for printing data, characterized by comprising means for receiving print data from a host computer, and means for printing the print data received. 4. The apparatus according to claim 3, wherein said density correction means converts an input density value of the print data into an output density value in a predetermined relationship based on said environmental condition information.
The image processing system for print data described in the above.