JP4748800B2 - Image processing device - Google Patents

Description

  The present invention relates to an image processing apparatus such as a printer, a copier, or a multifunction peripheral that performs processing for generating drawing data for two-color printing based on full-color color component data input together with a print command. The present invention relates to an image processing apparatus capable of further improving the reproducibility of two-color printing by reflecting the density of original full-color data in drawing data for two-color printing.

2. Description of the Related Art In recent years, there is a function called two-color printing as a function provided in an image processing apparatus such as a printer, a copier, or a multi-function machine capable of full color print output. Two-color printing is a printing method that is generally used because an image is composed of two colors, black and red or blue, and a color image effect can be obtained at low cost.
In two-color printing, the data input together with the print command is usually data indicated by R (red), G (green), and B (blue) of full-color color components. And drawing data specified by colors such as red and red. Note that black / red here usually corresponds to black / magenta of the developer.
In the conventional generation method of drawing data for two-color printing, for example, when the two colors are black and red, the pixel is determined based on the R, G, B data of the full-color color component input together with the print command. It was drawn separately in black and red. The following Patent Document 1 (Japanese Patent Laid-Open No. 2002-240361) shows an example of this method.
In the printer device described in Patent Document 1, since the density of each color of R, G, and B is specified as the full color component in the input print command data, the R, G, and B densities of the drawing target pixel are set. Each pixel is identified as red or black by checking whether or not the color is within a predetermined density range that defines red, and two black and red colors are drawn according to the determination result. Data is being generated.
JP 2002-240361 A

However, in the printer described in Patent Document 1, the pixel to be drawn is identified as red or black, and each pixel is drawn in either red or black according to the determination result, and the density is not taken into consideration. Therefore, the so-called “solid” drawing with no change in density is inevitably degrading the reproducibility of the original image.
By the way, conventionally, a printing method has been adopted in which a monochrome image is drawn in black based on the input R, G, B data of the full color components, and here, the density of the original data is reflected. The method to make is taken. However, this method is suitable only for drawing a monochrome image in black. That is, when the density of all three colors of R, G, and B is 100%, the density is 100% of black, and when the three colors of R, G, and B are overlapped, the color becomes black. This is a method of expressing black with a density close to the specified density value.
Therefore, even if the above-described density reflection method used for a black monochrome image is applied to red as it is, the density of red becomes light. For example, when pure red 100% (R density 100%, G density 0%, B density 0%) is drawn in black, it is expressed in light black because G and B are absent. Therefore, it is difficult to maintain the reproducibility of the original image in two-color printing depending on the prior art.
In addition, when it is appropriate to select a density reflection method according to a drawing object such as a line, an image, or a character, or a process using a density reflection method that the user thinks is not desirable may be performed. Since it does not consider the response to the case, there is a possibility of causing a problem.
An object of the present invention is to appropriately reflect the density specified in the original full-color component data in the drawing data of each color of the two-color printing in the two-color printing based on the input full-color color component data. It is to improve the reproducibility of the image. A second object of the present invention is to increase the usability by making it possible to select a density reflection method according to the drawing target and the user's request.

The invention of claim 1 is an image processing apparatus having data processing means for generating drawing data of a two-color pixel configuration based on R, G, B full-color component data input together with a print command, multiple data processing means, the input pixel to be processed represented by the density data of each color component of the full color, either to belongs categories are distinguished by color and density of pixels constituting the drawing data, predetermined a pixel determination means for determining according to the criteria of the stage, on the basis in accordance with the calculation method, R input, G, and B full color component data applied to each category that is distinguished by the pixel-size constant means, said drawing It is characterized by comprising density calculation means for calculating density data of each pixel of data .
According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the density calculating means calculates the density by multiplying the density of each color component of the full color by a predetermined coefficient and taking the sum of the obtained values. A means for calculating, wherein a numerical value determined for each category of the drawing data is used as the coefficient.
The invention of claim 3 is the image processing apparatus according to claim 2, have a operation means for enabling the setting input of the processing condition by the user, the coefficient used in the density calculating means from said operating means It is characterized by being changed by input.
According to a fourth aspect of the present invention, in the image processing apparatus according to any one of the first to third aspects, the full color component is R, G, B, and the two constituent colors of the drawing data are black, red, The red calculating means in the density calculating means is a means for converting the density value obtained by the black calculating means .
A fifth aspect of the present invention, in the image processing apparatus according to any one of 請 Motomeko 1 to 4, for each color of the drawing data, to specify the storage destination and the pattern of the gray scale pattern corresponding to the density And a means for acquiring from the table an ID for designating a gray scale pattern corresponding to the density calculated by the density calculation means .
The invention of claim 6 is an image processing apparatus having data processing means for generating drawing data of a two-color pixel configuration based on full-color color component data input together with a print command, wherein the data processing means A drawing object determination unit that determines whether the input pixel to be processed belongs to a line, an image, or a character drawing object, and among the pixels determined by the drawing object determination unit, the line or character drawing object Select a pixel with a line line width or character size that is smaller than the predetermined limit value, and select a density calculation method prepared for application to the drawing object to which the other pixels belong. And a method selected by the means for selecting a concentration calculation method. R, G, and based on the B full-color component data, characterized by comprising a concentration calculating means for calculating the density data of each pixel of the drawing data.
The invention of claim 7 is the image processing apparatus according to any one of claims 1 to 6, have a operation means for enabling the setting input of the processing condition by the user, the data processing means, said operation means The drawing data having the two constituent colors of 100% density is generated on the condition that the setting of the processing mode using the density calculating means is invalidated by the input from.

According to the present invention, the drawing density of the two-color printing is calculated for each color based on the density specified in the full-color color component data input together with the print command. The density can be appropriately reflected, and the reproducibility of the original image in two-color printing can be further improved.
Also, since a density calculation formula can be selected for each drawing object (line, image, character), appropriate drawing processing can be performed without impairing the characteristics of each object.
In addition, by making it possible to select a setting for 100% density for each color of two-color printing, the original 100% red density may be reduced depending on the processing method. It is possible to deal with a case where the processed data can be restored to the original image.

Embodiments relating to the image processing apparatus of the present invention will be described below.
In the embodiment described below, an example is shown in which a printer is used as an apparatus for implementing an image processing apparatus according to the present invention. The printer as the execution apparatus performs data processing such as drawing processing necessary for print output in accordance with a print command input from an operation panel provided in the apparatus main body or from an external host machine connected to a network or the like. I do. The external host machine includes a host PC, a management server, or a multifunction machine.
In the case of data generated by an external host machine, the data used for the print output input together with the print command is data created by an application for creating a document on the host PC. Alternatively, the document read data read by the scanner of the multifunction machine is the target. If the data is stored inside the apparatus, it is taken out from the storage location and treated as input data to be processed. In the following embodiment, the description will focus on the configuration and operation for performing print output in response to a print command from an external host machine.
The printer according to the present embodiment has a function capable of supporting full-color print output, and can receive full-color color component data as input data. In this example, it is assumed that the data format of the full-color color component is expressed by general-purpose R, G, and B handled by a document creation application or scanner reading. However, it may be expressed in other formats.

First, a basic configuration of a printer according to an embodiment of the present invention will be described.
FIG. 1 is a schematic diagram showing the hardware configuration of a printer according to this embodiment.
As shown in FIG. 1, the printer 1 includes a controller 2, an operation panel 4, a host I / F (interface) 5, a program ROM 6, a font ROM 7, a panel I / F 8, a CPU 9, a RAM 10, an NV-RAM 11, and an engine I / F 12. A printer engine 13, an option I / F 14, and an option memory 15.
The controller 2 converts the print data from the host machine 3 into drawing data (video data) according to the control mode set at that time and the control code instructed by the print command from the host machine 3 to the printer engine 13. This is a general term for the control mechanism to output, and is composed of the following modules.
The host I / F 5 is an I / F of a control signal and data from the host machine 3 to the printer 1 and a status signal from the printer 1 to the host machine 3.
The network I / F 16 is an I / F of control signals and data from the network 15 to the printer and status signals from the printer to the network.
The CPU 9 processes data (print data, control data) from the host machine 3 in accordance with the program ROM 6. The control data is data for instructing the control condition for each processing unit necessary for the printing process, and the processing condition or operation condition is set according to this data. Two-color printing related to the present plan can also be instructed by this data.

The RAM 10 is a work memory used by the CPU 9 for execution of processing. The RAM 10 is obtained after converting data from the host device 3 in units of pages and temporarily storing the data, and converting the data stored in the buffer into an actual print pattern. It is used for a bitmap memory for storing drawing data (video data).
The NV-RAM 11 is a nonvolatile RAM for storing data that is to be retained even when the power is turned off.
The program ROM 6 stores a program for processing and managing data in the controller 2 and controlling peripheral modules, and also stores a program for processing drawing data for two-color printing described later.
The font ROM 7 stores various types of font data used for printing.
The engine I / F 12 is an I / F for transmitting and receiving control signals and video signals from the controller 2 to the printer engine 13 and status signals from the printer to the controller.
Here, the printer engine 13 creates an electrostatic latent image on the photosensitive member by scanning exposure of a laser beam whose lighting is controlled by a video signal and a control signal from the controller 2, develops the toner, and supplies the toner image to the paper feeding unit. The image is transferred to a transfer paper supplied from the printer, and an image is formed through a fixing process. The printer engine 13 controls the paper discharge means when a paper discharge tray, sorter, punch or stapler is provided. In this embodiment, the printer engine is capable of operating in a full-color print mode and a two-color print mode.
The operation panel 4 includes a display unit that indicates the state of the printer 1 and a switch unit that switches the mode, font, and the like of the printer 1.
The panel I / F 8 is an I / F between the controller 2 and the operation panel 4.
The option I / F 14 is an I / F for connecting the printer main body and the option memory 15. The option memory 15 is a storage medium that is detachable from the printer main body, and is, for example, a memory card, a SIMM (Single In-line Memory Module), or a DIMM (Dual In-line Memory Module).

An outline of data processing in the printer 1 having the above-described configuration will be described.
The data sent from the host machine 3 via the host I / F 5 is analyzed by the CPU 9 according to the data analysis program on the program ROM 6, and the print data and print control data (SP, CR, LF, HT, VT,... Etc.) and others. The print data and print control data are temporarily stored in the reception buffer on the RAM 10. The received data once stored is taken out one by one by an emulation program, which is one of the control programs on the program ROM, and processed.
For example, if the extracted data is a character code, an intermediate code including a print position, a print size, a character code, font information, and the like is created and stored in an intermediate buffer provided on the RAM 10.
If the retrieved data is vector data, the emulation program will check each vector type (circle, straight line, curve, etc.), vector coordinates, vector attributes (line width, type of connection shape between lines) (Mitter connection, round connection, etc.), dotted line and solid line specification) etc. are converted into a data format that can be input to the drawing library, and the vector data received by the emulation in the drawing library is drawn into a bitmap. get.
If it is a command such as a control code or an escape sequence, a predefined process is performed on them. For example, if the number of copies to be printed is specified, the specified number of copies is set to be output (internal control information setting). If the print position is specified, the position of the next character code is specified. If the position is changed or the font is changed, the process is performed such that the font information of the next character code is set to the designated font.
In this way, when the print command from the host device 3 is processed or the processed data exceeds one page, the intermediate code stored in the intermediate buffer is converted into video data in accordance with the control program. Process.
When the conversion is completed, the controller 2 issues a print start command to the printer engine 13 through the engine I / F 12 and transfers video data in synchronization therewith.

Next, an embodiment relating to the two-color printing function in the printer 1 will be described in detail.
The printer according to the present embodiment has a function of receiving a print command having full color component data and processing data for full color print output.
In the data processing for performing full-color print output, first, the full-color color component data is obtained by decoding the print command. This full-color color component data is normally designated by R, G, and B, and the density of each color is designated. In the following description, it is assumed that data is input in R, G, and B.
After obtaining the data of the full color components expressed in R, G, and B, this data is input by the user from the control (setting) data instructed by the print command or the operation panel 4 provided in the printer 1. Used for processing drawing data together with setting data. In the process of processing drawing data, drawing data of color components corresponding to toners of four colors (yellow: Y, magenta: M, cyan: C, black: BK) used by the printer engine 13 in the printer 1 for image formation. Process to generate.
In addition to performing processing necessary for full-color print output, it has a two-color printing function that can obtain the effect of a color image at low cost. In two-color printing, printing processing is performed using two of the four color toners used in the above-described full-color printing mode. Therefore, the two-color printing is expressed by R, G, and B obtained by decoding the printing command. Drawing data for two colors is generated from the data of the full color components. In the present embodiment, black and red corresponding to toner black and magenta are often used, and therefore, red / black two-color printing will be described as an example.
As a method of generating drawing data for black / red two-color printing from data of full color components expressed in R, G, and B, a conventionally proposed method is based on input R, G, and B data. Is distinguished from black and red, and red / black printing drawing data is generated, and it has not been considered to reflect the density data of each of the original colors R, G, and B (See “Issues to be solved”). For this reason, the reproducibility of the original image is reduced.

Therefore, in this proposal, the reproducibility of the original image is improved by generating drawing data for red / black two-color printing that reflects the density data of the input full-color component data expressed in R, G, and B. Make it possible.
The drawing data generation process for red / black two-color printing in this proposal is performed according to the basic processes shown in (1) to (3) below.
(1) Acquire input R, G, B full color component data.
(2) Based on the input density data of the R, G, and B full-color components, each pixel is distinguished as either red or black for two-color printing according to the criterion.
(3) Based on the input R, G, B full-color component density data, according to the density calculation method applied to each of red and black for two-color printing, the red and black densities distinguished in (2) above Ask for data.
As data processing when two-color printing is instructed in the print command, an embodiment related to a processing process for executing drawing data generation processing according to the above (1) to (3) will be described below.
The following “Embodiment 1” shows a basic form of the drawing data generation process according to the above (1) to (3).
“Embodiment 2” shows a mode in which red density data is obtained by converting black calculated density.
“Embodiment 3” shows a mode in which the calculation method of red density data can be changed by user setting.
“Embodiment 4” shows a mode in which red pixels are determined in a plurality of stages, and different density calculation methods are applied to the pixels determined in each stage.
Further, “Embodiment 5” indicates a form in which processing for selecting a density calculation method corresponding to a drawing object is performed.
“Embodiment 6” shows a mode in which the density calculation process that reflects the density of the original data is invalidated by the user setting, and 100% drawing processing is performed for both red and black.

“Embodiment 1”
This embodiment shows a basic form of processing for generating drawing data for red / black two-color printing reflecting the density of original data.
FIG. 2 is a flowchart of data processing related to drawing data generation processing for red / black two-color printing according to this embodiment. The processing process of this embodiment will be described below according to the flow of FIG.
When the controller 2 receives a print command from the host machine 3 via the host I / F 5, the controller 2 activates a program for processing the command data and decodes the received command to obtain the RGB command parameters specified in full color. Read (step S101). The command parameter indicates density data for each color of RGB.
Next, the RGB value indicated by the external host device 3 received as the print command data value is converted into a data value used for processing in the controller 2 of the printer 1 (step S102).
Thereafter, processing specific to the present plan, which is performed when two-color printing is set, is executed. Here, the density (grayscale) value for black drawing for two-color printing is calculated (step S103).
As an example of the formula for calculating the black density,
Density = Coefficient for red x R + Coefficient for green x G + Coefficient for blue x B (1)
Is used. In the above equation (1), R, G, and B represent density data of each color of input RGB, and the coefficient for each color of R, G, and B takes a positive value less than 1 and assigns an empirical value. In addition, the data values converted for internal processing obtained in step S102 may be used for R, G, and B in equation (1).
In this step, a pattern ID for designating a gray scale pattern corresponding to the density is acquired from the calculated density for black drawing, and the density is represented by the pattern ID.
FIG. 3 shows an example of a table used to associate a density with a grayscale pattern and select a pattern. The table shown in FIG. 3 associates the three pointers indicating the storage location of the density, pattern ID, and gray scale pattern. Using the table shown in FIG. 3, the pattern ID is obtained from the calculated density, and the grayscale pattern used when generating the drawing (printing) data is accessed from the pattern ID to the storage location designated by the pointer, and the data is stored. obtain. The storage location of the gray scale pattern may be any of ROM 6, RAM 10, and NVRAM 11.

Here, it is determined whether the pixel of the RGB command designated in full color is red or black (step S104). The RGB data of the target pixel is used as the density data for internal processing obtained in the previous step S102, and on the basis of this, each pixel is discriminated as either red or black for two-color printing according to the criterion.
As an example of the determination method, a red range is defined, and if the data is within the range defined by the pixel, the data is determined to be red. The red range is suitably defined under the conditions that the density of G and B is low and the density of R is high, and the density value that defines the range is a value obtained experimentally in advance.
In accordance with the result of determining whether the pixel of the RGB command is red or black, drawing data having density data obtained by a calculation formula suitable for each color is generated.
As a processing flow, it is checked whether the determination result is black or red (step S105). If the determination result is black, the pattern ID for designating the grayscale pattern obtained in step S103 is set to the black pixel. Gradation is given as drawing data.
On the other hand, when the determination result is red (step S105-NO), the density (gray scale) value for red drawing of two-color printing is calculated and a gradation is given (step S107). The method for calculating the red density is basically based on a method of obtaining data in accordance with a calculation formula that assigns values for calculating red as the respective coefficients of R, G, and B in the above formula (1). Note that the coefficient value is the same as that in the above black calculation in that an empirical value is assigned. However, in the case of red, the coefficient R in Equation (1) takes a larger value than other colors. Also in this step, a pattern ID for designating a gray scale pattern corresponding to the density is acquired from the calculated density for red drawing, and the density is represented by the pattern ID.
Next, the pattern ID for designating the gray scale pattern obtained in the previous stage is used as the drawing data of this red pixel (step S108).
After generating black or red drawing data (steps S106 and S108), the processing flow is finished.
The calculation of the black density is performed in the preceding stage of step S104 in which the pixel red / black (drawing color) determination process is performed in the flow of FIG. 2, but may be performed after the black drawing is determined. good. This example is schematically shown in the flow of FIG. In this figure, the drawing procedure of red and black is determined (step S401), and according to the result, the processing procedure (steps S402 and S403) for obtaining the density of each color of red and black by a suitable calculation method is obtained. Yes.
As described above, the density of the original data can be appropriately reflected in the drawing data of each color of red and black in the two-color printing, and the reproducibility of the original image in the two-color printing can be further improved.
In the above description, two-color printing of red and black has been described as an example. However, other color combinations can be similarly implemented by using a different density calculation method for each color.

“Embodiment 2”
This embodiment is based on the first embodiment showing the basic form of processing for generating red / black two-color printing drawing data that reflects the density of the original data. This is a process obtained by conversion.
Therefore, the entire drawing data generation process for red / black two-color printing is basically performed according to the flow shown in FIG. 2 of the first embodiment. However, in the present embodiment, the processing for calculating the density (grayscale) value for red drawing and giving the gradation (step S107) is different from that in the first embodiment. This step is a process of converting the calculated density of black.
FIG. 5 shows a processing flow of the present embodiment for calculating the density (grayscale) value for red drawing performed in step S107 of FIG. The processing process of this embodiment will be described below according to the flow of FIG.
In the flow of FIG. 5, first, it is checked whether or not it is necessary to convert the density for black drawing calculated in step S103 of FIG. 2 to red (step S201). As an example of this check, whether or not the target pixel has a darker density than the value calculated as the density for black drawing when the R data of the target pixel is R100%, G0%, B0% (red 100% density). Find out.
If the result of this check is a high density (step S202-YES), a conversion process for increasing the density for red is performed (step S203). For example, this conversion process is performed by a method of multiplying a density value for black drawing by a predetermined coefficient larger than 1. This coefficient is a value obtained as an empirical value.
If the density is not high as a result of the check in step S201, the gray scale pattern obtained as the density value for black drawing is used as it is for red drawing.
By adopting the above method, it is possible to adjust the drawing of the specified color with a density of 100% pure red with a light density, and to easily process the drawing data of red / black two-color printing with a more appropriate density It can be generated by the system.

“Embodiment 3”
The present embodiment is based on the first embodiment showing the basic form of the processing for generating the drawing data for red / black two-color printing reflecting the densities of the input R, G, and B full-color data. This calculation method can be changed by user settings.
In the first embodiment, empirical values are assigned to the coefficients to be multiplied by the R, G, and B density values in the red density data calculation formula. The coefficient values determined in this way are given values that can be recognized as appropriate by human experience as the density when the inputs R, G, B are expressed in red. For example, R, G, and B values that are recognized as red with 100% density are set to values that bring the red toner closer to 100% density. However, the coefficient value obtained empirically may not always be red as desired by the user.
Therefore, in the present embodiment, as a means for making it possible to eliminate this difference, the setting of the coefficient of the density calculation formula is changed by a user operation so that the calculation method can be changed.
FIG. 6 shows a processing flow of this embodiment in which the setting of the coefficient of the density calculation formula can be changed by a user operation. The processing process of this embodiment will be described below according to the flow of FIG.
In the flow of FIG. 6, first, the controller 2 checks whether or not a command for designating the coefficient of the density calculation formula for red according to the user setting has been input (step S301). As an input method of this command, an operation input from the operation panel 4 or an input from the host I / F 5 by a user setting operation in the host device 3 is performed. Further, the item input by the user at the time of the setting operation may be designated not by the coefficient but by the darkness of red and converted to the coefficient of the density calculation formula for red on the printer side.
If, as a result of the check, the coefficient for the red calculation formula is not specified by the user (step S301-NO), an initial value is set for the coefficient of the density calculation formula for red (step S306). As described above, the initial value of this coefficient is suitable when the color specified by R, G, B of the target pixel is drawn in red, and the density of the color specified by R, G, B is appropriate in red. The value prepared by the system in advance as a value that enables drawing with density.
On the other hand, when the coefficient of the calculation formula for red is designated (step S301-YES), the coefficient information designated by the user is decoded and set as a variable for internal processing (step S302).
Next, it is checked whether or not the coefficient information designated by the user is within an appropriate range for calculating the red density (step S303). If the coefficient information is not suitable for calculating the red density ( In step S304-YES), the coefficient is set to an initial value as in step S301-NO.
If the coefficient designated by the user is in a range suitable for calculating the red density (NO in step S304), the value of the density calculation formula for red is replaced with the value designated by the user.
After setting the value of the density calculation formula for red, the processing of this processing flow is terminated.
As described above, the red density data calculation method can be changed by the user setting, whereby the red density can be adjusted to a user desired density.

“Embodiment 4”
The present embodiment is based on the first embodiment showing the basic form of processing for generating red / black two-color drawing data reflecting the density of the original data, and determines red pixels in a plurality of stages. This is a process of applying different density calculation methods to the pixels determined at each stage.
FIG. 7 shows a flow chart of data processing related to drawing data generation processing for red / black two-color printing of this embodiment. The processing process of this embodiment will be described below according to the flow of FIG.
When the controller 2 receives a print command from the host machine 3 via the host I / F 5, the controller 2 activates a program for processing the command data and decodes the received command to obtain the RGB command parameters specified in full color. Read (step S401). The command parameter indicates density data for each color of RGB.
Next, it is determined whether the pixel of the RGB command designated in full color is red or black. In the present embodiment, the red determination criteria are set to three levels, and the density calculation is performed on the pixels determined to be red in each stage using a red density calculation formula suitable for each.
Therefore, first, the first stage determination process is performed (step S402). The determination in the first stage is a step of checking that there is only an R color component and no G and B color components for each of R, G, and B values specified by the full color command.
As a result of this determination, if it is determined that the drawing is performed in red (step S403-YES), the density calculation formula suitable for pure red is selected because it meets the first-stage criterion for determining pure red (step S403-YES). S404).
Next, a second stage determination process is performed (step S405). The determination in the second stage is a process of determining whether to draw in red or black when the color component of G or B is included instead of pure red. The criterion for determination is that information on the range of G and B to be determined as red when the red color component is dark is defined in advance, and whether to draw in red or black according to this criterion Determine.
As a result of this determination, if it is determined to draw in red (step S406-YES), a density calculation formula suitable for red as the determination criterion is selected (step S407).
Next, a third stage determination process is performed (step S408). The determination of the third level is a process for determining whether to draw in red or black when the red color is lighter than the first level and the second level. As a determination criterion, information on the range of G and B to be determined as red in this category is defined in advance, and it is determined whether to draw in red or black in light of this criterion.
As a result of this determination, if it is determined that the drawing is performed in red (step S409-YES), a density calculation formula suitable for red as the determination criterion is selected (step S410).
As described above, red is determined in three stages, and when red is determined, selection of the density calculation formula to be applied can be performed by a table method. FIG. 8 shows an example of a table used for associating the determined red category with the selected density calculation formula for red and selecting the density calculation formula. Using the table shown in FIG. 8, a density calculation formula to be applied is acquired from the determined red category and used when generating drawing (printing) data.
Note that pixels that are not determined to be red in the third determination of red in the flow illustrated in FIG. 7 are determined to be black, and processing for generating black drawing (printing) data is performed.
As described above, even in red, the difference in color is divided into a plurality of stages, and the density calculation formula suitable for each is used, so that the reproducibility to the original data can be further improved.

“Embodiment 5”
In the present embodiment, a density calculation method is selected corresponding to a drawing object, and processing for generating drawing data for red / black two-color printing reflecting the density of the original data is performed.
FIG. 9 is a flowchart of data processing related to drawing data generation processing for red / black two-color printing according to this embodiment. The processing process of this embodiment will be described below according to the flow of FIG.
When the controller 2 receives a print command from the host machine 3 via the host I / F 5, the controller 2 starts a program for processing the command data. Although not shown in the illustrated flow, the controller 2 reads the RGB command parameters specified in full color by decoding the received command, and the command is processed as a line, image, or character drawing object. If it is, the drawing command indicating the type of object is read.
In the flow of FIG. 9, in order to generate drawing data for two-color printing corresponding to a drawing object, it is first determined from the read drawing command whether the object to be drawn is a line (step S501).
If the drawing object is a line, it is determined whether or not the line width of the line to be drawn is larger than a certain number of dots (step S502). The fixed number of dots determined in this step is a value that defines a limit of the number of dots at which a line to be drawn is interrupted when a density is specified and drawn. This limit value is a value determined by the specifications and quality of the printer engine 13.
Therefore, if the line width is larger than this limit value (step S502-YES), a density calculation method suitable for the case where the drawing object is a line is selected (step S503).
If the line width is smaller than the limit value (step S502-NO), the density designation for the pixel for drawing this line is invalidated, and the pixel for drawing this line is set to 100% density (step S504).

If the drawing object is not a line in step S501, it is next determined from the read drawing command whether the object to be drawn is an image (step S505).
If the drawing object is an image, a density calculation method suitable for the case where the drawing object is an image is selected (step S506).
On the other hand, if the object to be drawn is not an image (step S505-NO), it is next determined from the read drawing command whether the object to be drawn is a character (step S507).
If the drawing object is a character, it is determined whether or not the size of the character to be drawn is larger than a certain size (step S508). The fixed size determined in this step is a value that defines a size limit at which a character line cannot be drawn when a character is drawn with a density specified. This limit value is a value determined by the specifications and quality of the printer engine 13.
Therefore, if the character size is larger than the limit value (step S508: YES), a density calculation method suitable for the case where the drawing object is a character is selected (step S509).
If the character size is smaller than the limit value (step S508-NO), the density designation for the pixel for drawing the character is invalidated, and the pixel for drawing the character is set to 100% density (step S510).
As described above, the three types of drawing objects are determined, the respective objects are determined, and the selection of the density calculation formula used when applying the density calculation formula can be performed by a table method. FIG. 10 shows an example of a table used for associating three types of drawing objects with a density calculation formula to be selected and selecting the density calculation formula. Using the table shown in FIG. 10, a density calculation formula to be applied is acquired from the determined line, image, and character drawing objects, and used when generating drawing (printing) data.
If it is determined that none of the three types of drawing objects in the flow shown in FIG. 7 corresponds to any of the drawing objects (step S507-NO), the drawing (printing) data is obtained according to the first to fourth embodiments. Generate the process.
As mentioned above, the density calculation formula can be selected for each drawing object of the line, image, and character, so select the density calculation method that can draw without blurring the line, and for the image You can select a calculation method that can specify the density finely, and you can select a calculation formula that does not blur the shape of characters, so that appropriate drawing can be done without impairing the characteristics of each object. Can be processed.

“Embodiment 6”
In the present embodiment, the density calculation process for reflecting the density of the original data according to the user setting when the drawing process of the red / black two-color printing that reflects the density of the original data is performed according to each of the above embodiments. Is disabled and 100% drawing processing is performed for both red and black.
For example, in scanner read data obtained by reading a document with fading or dirt on the background with a scanner, a portion originally drawn with 100% pure red may be lightened. If a red / black two-color printing request is made based on such data, the density will be further reduced in the drawing data generation process of this proposal. In such a case, the full color designation command is simply divided into red and black. It is preferable for the user to draw at a density of 100%.
In order to be able to deal with such a case, in the present embodiment, the density calculation process that reflects the density of the current data is disabled, and 100% drawing processing is performed for both red and black. It is possible to deal with cases where the concentration can be restored.
FIG. 11 is a flowchart of data processing related to drawing data generation processing for red / black two-color printing according to this embodiment. The processing process of this embodiment will be described below according to the flow of FIG.
In the flow of FIG. 11, first, the controller 2 checks an instruction to enable or disable the execution of drawing that reflects the density of the original data performed by the user (step S <b> 601). This command input method is based on operation input from the operation panel 4 or input from the host I / F 5 by user setting operation on the host device 3.

If there is no command instructed by the user as a result of the check (step S601-NO), nothing is done and the process flow is exited.
On the other hand, when there is a user command (step S601-YES), information on whether or not the execution of the drawing process reflecting the density of the original data instructed by the user is validated or invalidated is read and used for internal processing. Into the variable. (Step S602).
Next, since the process branches according to the user's instruction, a variable for internal processing is checked whether to enable or disable the execution of the drawing process (step S603). The processing information inside the printer is set so as to generate the drawing data for red / black two-color printing reflecting the density data.
On the other hand, when disabling, setting the processing information inside the printer so that the density data of the color specified by the full color command is not reflected in the drawing, and setting to perform 100% drawing processing for both red and black I do.
By performing the processing flow described above, it is possible to generate drawing data for red / black two-color printing that enables restoration to the original image requested by the user.

1 shows a schematic hardware configuration of a printer according to an embodiment of the present invention. A flow of data processing (embodiment 1) related to processing for generating drawing data for red / black two-color printing is shown. The table which linked | related 3 persons of the pointer which shows the memory | storage location of density | concentration, pattern ID, and a gray scale pattern is shown. The flow which performs the process calculated | required with the density | concentration calculation method suitable for each color of red and black in the procedure different from FIG. 2 is shown roughly. A processing flow (second embodiment) for calculating a density value for red drawing by converting the calculated density of black is shown. 10 shows a processing flow (third embodiment) in which the setting of the coefficient of the density calculation formula can be changed by a user operation. A flow of data processing (embodiment 4) related to processing for generating drawing data for red / black two-color printing is shown. The table which linked | related the determined red category and the density | concentration formula for red to select is shown. 10 shows a processing flow (Embodiment 5) that enables a density calculation formula to be selected corresponding to a drawing object. An error notification execution condition (A) and a notification operation example (B) performed according to the execution condition are shown. A flow (Sixth Embodiment) of processing for rendering 100% red / black with the density calculation processing invalidated by the dark user setting is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer 2 ... Controller 3 ... Host machine 4 ... Operation panel 5 ... Host I / F, 6 ... Program ROM, 8 ... Panel I / F, 9 ... CPU, 10 ..RAM, 11.NVRAM, 12.Engine I / F, 13.Printer engine.

Claims (7)

An image processing apparatus having data processing means for generating drawing data of a two-color pixel configuration based on R, G, B full-color color component data input together with a print command,
The data processing means determines in advance which of the categories the input pixel to be processed represented by the density data of each color component of the full color belongs to the color and density of the pixels constituting the drawing data . a pixel determination means for determining according to the criteria of the plurality of stages,
According calculation method to be applied to each category that is distinguished by the pixel-size constant means, the input R, on the basis of G, and B full-color component data, the concentration calculation for calculating the density data of each pixel of the drawing data An image processing apparatus comprising means. The image processing apparatus according to claim 1,
The density calculating means is a means for calculating the density by multiplying the density of each color component of a full color by a predetermined coefficient and summing the obtained values, and the coefficient is a numerical value determined for each category of the drawing data. An image processing apparatus using The image processing apparatus according to claim 2,
Have a operation means for enabling the setting input of the processing condition by the user,
An image processing apparatus, wherein the coefficient used in the density calculating means is changed by an input from the operating means. The image processing apparatus according to any one of claims 1 to 3,
The full color component is R, G, B, and the two constituent colors of the drawing data are black, red,
The image processing apparatus according to claim 1, wherein the calculation unit for red in the density calculation unit is a unit that converts the density value obtained by the calculation unit for black . The image processing apparatus according to any one of 請 Motomeko 1 to 4,
For each color of the drawing data, a table that associates a storage destination of a gray scale pattern corresponding to the density and an ID for designating the pattern,
An image processing apparatus comprising: means for acquiring an ID for designating a gray scale pattern corresponding to the density calculated by the density calculating means from the table . An image processing apparatus having data processing means for generating drawing data of a two-color pixel configuration based on full-color color component data input together with a print command,
The data processing means includes a drawing object determination means for determining whether an input pixel to be processed belongs to a line, an image, or a character drawing object;
Among the pixels determined by the drawing object determination means, the constituent pixels of the line line width or character size belonging to the line and character drawing objects and smaller than the predetermined limit value are selected to be 100% density. Means for selecting a density calculation method prepared for application to the drawing object to which the other pixels belong;
According to a method selected by the means for selecting a density calculation method, density calculation means for calculating density data of each pixel of the drawing data based on input R, G, B full color component data is provided. An image processing apparatus. The image processing apparatus according to any one of claims 1 to 6,
Have a operation means for enabling the setting input of the processing condition by the user,
The data processing unit generates the drawing data having two constituent colors of 100% density on condition that the setting of the processing mode using the density calculating unit is invalidated by an input from the operation unit. An image processing apparatus.

Images