JP2005125508A - Device, method and program for forming data corresponding to dot type, print controller, print control method and print control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form data corresponding to the dot type, e.g. a dot distribution table, easily. <P>SOLUTION: Gray level range of gradation data (input gradation data) constituting CMYKcm data is divided into a plurality of gradation sections 1-3 and dot distribution tables (dot type correspondence data) T1-T3 defining correspondence between the input gradation data and the output gradation data indicating the amount of a plurality of kinds of dot to be formed at each gray level for each kind of dot are made. Since the number of corresponding gray levels is decreased when the dot distribution table is made, distribution of dots can be designed easily and the dot distribution table can be made easily. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dot type correspondence data creation device, a dot type correspondence data creation method, a dot type correspondence data creation program, a print control device, a print control method, and a print control program.

  Recent inkjet printers are capable of ejecting ink of three types of large, medium, and small dot diameters with different ink amounts from each nozzle, and the area of the dot of each pixel is set to three or more gradations depending on the presence or absence of these dots. The gradation is expressed by so-called area gradation. If 3 or more gradations are expressed by this area gradation, even if the formation density of each type of dot is expressed by 256 gradations, it is possible to express substantially more than 256 gradations. The image quality of the printed image can be improved.

When performing print control for such a printer, input tone data representing the amount of ink used in the printer is converted into output tone data representing the dot formation amount for large, medium and small, Printing control is performed using the output gradation data. A dot allocation table that defines the correspondence between the input gradation data and the output gradation data is created for reference when converting the input gradation data to the output gradation data. This dot distribution table is an information table in which output gradation values are stored for each type of dot for all gradations of input gradation data, and is described in, for example, Patent Document 1 as a table that gives ink amounts by dot diameter. ing. Therefore, in order to create a dot sort table, if the input tone data is 256 tones, sort the types of dots to be formed for all 256 steps, and determine 256 steps of output tone values for each dot type. There is a need to.
JP 11-348322 A (paragraph 0093-0102, FIG. 22)

In recent years, it has been demanded to shorten the development period of printer products, and there has been a desire to facilitate a design for distributing the types of dots formed in each gradation.
In addition, although the printed image has a high image quality by expressing the gradation by the area gradation described above, there is a demand for further improving the image quality of the printed image, and further increasing the number of types of dots and finely printing the image. There is hope to express. However, if it is attempted to distribute four or more types of dots using a single dot allocation table, it is difficult to design how the dots are allocated, which is not practical.

  The present invention has been made in view of the above problems, and a dot type correspondence data creation device, a dot type correspondence data creation method, and a dot type correspondence that can easily create dot type correspondence data such as a dot allocation table. An object is to provide a data creation program, a print control apparatus, a print control method, and a print control program.

Means for Solving the Problems and Effects of the Invention

In order to achieve the above object, the present invention provides input gradation data representing the amount of ink used in a printing apparatus capable of forming a predetermined number of types of dots having different ink amounts on a print medium, and Correspondence between output gradation data representing the formation amount of multiple types of dots by the same type is specified, and dot types for reference when converting the same input gradation data to the same output gradation data A dot type corresponding data creation device for creating data, wherein the gradation range that the value of the input gradation data can take is divided into a plurality of gradation sections, and the input gradation data for each divided gradation section, It is characterized by creating dot type correspondence data for each gradation section that defines a correspondence relationship with output gradation data representing the formation amount of a plurality of types of dots in each gradation for the same type.
That is, the dot type correspondence data is created in units of gradation sections that are narrower than the gradation range that the value of the input gradation data can take. Then, since the number of gradations to be corresponded when creating the dot type correspondence data is reduced, it is easy to design how the dots are distributed. Therefore, it is possible to easily create dot type correspondence data such as a dot distribution table.

Here, the dot type correspondence data may be data in the information table format, or data not in the information table format.
The ink amount may be the weight of the ink or the volume of the ink.

The output gradation data may be data representing the formation amounts of a plurality of types of dots smaller than the predetermined number by the same type. Then, when distributing dots of different types with different ink amounts, it is possible to distribute dots with a realistic number of types, so it is not difficult to design how to distribute the dots. Therefore, it becomes possible to create dot type correspondence data more easily.
Here, the number of types is not limited as long as the plurality of types of dots corresponding to each gradation section are two or more types of dots. The number of types is not limited as long as the predetermined number of types of dots that can be formed by the printing apparatus is larger than the number of types of dots associated with each gradation interval. For example, the same predetermined number may be 3 and two types of dots may correspond to the gradation interval, or the predetermined number may be 4 or more and the three types of dots may correspond to the gradation interval.

  The plurality of gradation sections include at least a first gradation section and a second gradation section on the high gradation side that uses more ink than the first gradation section, and the second gradation section The plurality of types of dots corresponding to the gradation interval may include at least a type of dot having a larger amount of ink than all types of dots corresponding to the first gradation interval. The higher the gradation range, the more dots of ink are included, making it easier to design how to distribute the dots and making it easier to create dot type data. It becomes possible to create.

  The plurality of types of dots corresponding to the gradation interval may be a plurality of types of dots that are consecutive in order of ink amount among the predetermined number of types of dots. Then, since the dots can be formed by effectively using the types of dots that can be formed by the printing apparatus, it is possible to create dot type correspondence data that expresses a higher-quality print image.

  Among the plurality of gradation intervals, a plurality of types of dots corresponding to each of the gradation intervals adjacent to each other in the order of the gradation value may include the same type of dots. Then, since it is possible to prevent jumps in area gradation between adjacent gradation sections, it is possible to create dot type correspondence data that represents a higher quality print image.

  When the printing apparatus is capable of forming a plurality of color ink dots on the print medium, the gradation interval may be separated from the gradation range corresponding to each of the ink colors. Since an appropriate type of dot can be formed according to the color of the ink, it is possible to create dot type correspondence data that expresses a higher quality image.

Further, when the printing apparatus can form at least first and second ink dots on the printing medium and the first ink is darker than the second ink, the gradation section Is divided from the gradation range corresponding to each of the first and second inks, and the gradation interval corresponding to the first ink is a gradation interval corresponding to the second ink. It may be on the high gradation side where more ink is used. When the ink is dark, the gradation interval is set to a higher gradation side, and dots with a smaller amount of ink are easily formed. When the ink is dark, the graininess of the dots tends to be noticeable, but the dot graininess becomes less noticeable by forming dots with a smaller amount of ink. As described above, since an appropriate type of dot can be formed according to the density of the ink, it is possible to create dot type correspondence data that expresses a higher quality print image.
Here, when the gradation interval corresponding to the first ink is higher than the gradation interval corresponding to the second ink, both the upper and lower limits of the upper and lower limits of the gradation interval of both inks. The gradation range corresponding to the first ink is higher gradation side, the upper limit is the same, and the lower limit only The gradation interval corresponding to the first ink is higher gradation side, the lower limit is the same, only the upper limit corresponds to the first ink This includes the case where the gradation section to be performed is on the higher gradation side.

The darkness of the ink can be determined by the brightness when dots of the same ink amount are formed on the print medium in equal amounts. The brighter the ink, the thinner the ink, and the darker the brighter the ink. The brightness is preferably brightness, but may be brightness or the like. The brightness is a dot that expresses a higher-quality image if the brightness is included as a color component amount in a uniform color space (CIE 1976) or a device-independent color space defined by the International Commission on Illumination (CIE). Type correspondence data can be created.
For example, when the printing apparatus uses six colors of CMYKcm (cyan, magenta, yellow, black, light cyan, and light magenta), all of the CMYKcm inks have different densities, but the K inks are darker than the CM inks. The ink is darker than the Ycm ink. Therefore, K ink may be used as the first ink, at least one type of CMYcm ink may be used as the second ink, at least one type of KCM ink may be used as the first ink, and at least one type of Ycm ink may be used as the second ink. it can.

  The plurality of types of dots corresponding to the gradation interval may be two or three types of dots among the predetermined number of types of dots. If there are four or more dots to be distributed by one dot type correspondence data, it becomes difficult to distribute the dots, but it is easy to distribute three or less types of dots. Therefore, it is possible to further facilitate the design of how the dots are distributed and to create the dot type correspondence data more easily.

  By the way, as in the invention according to claim 10, the dot type correspondence data defining the correspondence relationship of the gradation intervals corresponding to the input gradation data is referred to from among the dot type correspondence data defined for each gradation interval. Thus, when the print control device that converts the input grayscale data into the output grayscale data and performs print control of the printing device using the converted output grayscale data, the dots used in the print control device are configured. Since the dot type corresponding data defined for each gradation section may be generated when generating the type corresponding data, the dot type corresponding data can be easily generated. That is, the present invention can be applied to the invention according to claim 10, and the configurations described in claims 2 to 7 can be applied to the print control apparatus.

  It should be noted that the dot type correspondence data creation device and the print control device described above include various aspects as the idea of the invention, such as being implemented together with other methods in a state of being incorporated in a certain device. It can be changed as appropriate. In addition, since it is possible to proceed with processing according to a predetermined procedure corresponding to the above configuration, the present invention can also be applied as a control method, and the inventions according to claims 8 and 11 also basically apply. Has similar actions and effects. Furthermore, the present invention can also be applied to a printing system including a printing unit that prints an image by forming dots, and basically has the same operations and effects.

When trying to implement the present invention, a predetermined control program may be executed by the above-described apparatus. Therefore, the programs described in claims 9 and 12 basically have the same operations and effects. In addition, it is conceivable that a medium on which the program is recorded is distributed and the program is appropriately read from the recording medium into a computer. Therefore, the present invention can be applied as a computer-readable recording medium on which the program is recorded. Has similar actions and effects.
Of course, it is possible to make the configuration described in claims 2 to 7 correspond to the method, the program, and the recording medium.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of printing system:
(2) Creation method and creation process of dot type correspondence data:
(3) Processing performed by the print control apparatus:
(4) Various modifications:

(1) Configuration of printing system:
FIG. 1 shows a printing system comprising a personal computer (PC) 10 serving as a dot type correspondence data creating apparatus and a printing control apparatus according to the present invention, a color printing inkjet printer 20 serving as a printing apparatus (printing means), and the like. Is shown. Of course, the computer used in the present invention is not limited to a PC. In the PC 10, the CPU 11 serving as the center of the arithmetic processing controls the entire PC via the system bus 10a. The bus 10a includes a ROM 12 which is a non-rewritable semiconductor memory, a RAM 13 which is a rewritable semiconductor memory, a CD-ROM drive 15, a flexible disk (FD) drive 16, various interfaces (I / F) 17a to 17e, etc. And a hard disk (HD) 14 that is a magnetic disk is also connected via a hard disk drive.

  The HD 14 stores an operating system (OS), an application program (APL), and the like, and is appropriately transferred to the RAM 13 and executed by the CPU 11 at the time of execution. The HD 14 stores a printer driver 14a, a dot assignment table (hereinafter referred to as a dot table) 14b which is dot type correspondence data of the present invention, and a color conversion table (color conversion LUT) (not shown). A digital camera 30 or the like can be connected to the I / F 17a (eg, USB I / F), and a display 18a that displays an image corresponding to the image data based on the color image data is connected to the CRTI / F 17b. A keyboard 18b and a mouse 18c are connected as operation input devices to the I / F 17c, and a printer 20 is connected to the printer I / F 17e via, for example, a parallel I / F cable (a serial I / F cable is also possible). .

The printer 20 prints a print image corresponding to image data by forming dots on a print sheet (print medium) using CMYKcm ink mounted on the cartridge 25a. Of course, a printer that uses light black, dark yellow, non-colored ink, or the like may be employed, or a printer that does not use any of CMYKcm inks may be employed. Various printing apparatuses such as a bubble printer that generates bubbles in the ink passage and discharges the ink and a laser printer that prints a print image on a print medium using toner ink can be employed.
In the printer 20, a CPU 21, a ROM 22, a RAM 23, a communication I / O 24, a control IC 25, an ASIC 26, an I / F 27, and the like are connected via a bus 20 a, and the CPU 21 controls each unit according to a program written in the ROM 22.

  The communication I / O 24 is connected to the printer I / F 17e of the PC 10, and the printer 20 receives raster data for each color transmitted from the PC 10 via the communication I / O 24. The ASIC 26 outputs applied voltage data corresponding to the raster data to the head driving unit 26a while transmitting / receiving a predetermined signal to / from the CPU 21. The head drive unit 26a generates an applied voltage pattern to the piezo element built in the print head from the applied voltage data, and causes the print head to eject six colors of ink in dot units. The carriage mechanism 27a and the paper feed mechanism 27b connected to the I / F 27 perform main scanning of the print head, and sequentially feed the printing paper while performing page break operation as appropriate, and perform sub-scanning.

The print head is provided with a plurality of inkjet nozzles for each color of CMYKcm, and a piezoelectric element is arranged corresponding to each of the nozzles.
As shown in FIG. 2, the piezo element PE is installed at a position in contact with the ink passage 25b that guides ink to the nozzle Nz, and when a voltage having a predetermined time width is applied between the electrodes provided at both ends of the piezo element PE. Then, the voltage is extended for the time of voltage application, and one side wall of the ink passage 25b is deformed. As a result, the volume of the ink passage 25b contracts according to the expansion of the piezo element PE, and the ink corresponding to the contraction becomes ink droplets Ip and is ejected from the tip of the nozzle Nz at a high speed and soaks into the printing medium. Dots are formed and printing is performed.

  In the figure, driving waveforms for forming a predetermined number of types of dots having different ink amounts are shown, and dots having different ink amounts are formed by the driving waveforms V1 and V2 in a predetermined period. Since the degree of expansion and contraction of the piezo element increases as the voltage difference between the drive waveforms increases, the dot becomes larger. As shown in the lower part of the figure, this printer 20 has six types (predetermined number of types) of 1.6, 3, 5, 7, 12, and 22 set as dot ink amounts (in ng units). Six types of dots can be formed on the print medium. The raster data transmitted from the PC to the printer is added with identification information for identifying the type of dot, and the printer forms a type of dot corresponding to the identification information.

In the PC 10, a printer driver and the like for controlling the printer I / F 17e are incorporated in the OS, and various controls are executed as a part of the OS. APL exchanges data with hardware via the OS. The printer driver is operated when the APL printing function is executed, and can perform bidirectional communication with the printer 20 via the printer I / F 17e, and via an OS incorporating a GDI (Graphics Device Interface) or the like. The image data is received from the APL, converted into raster data, and sent to the printer 20.
The dot type correspondence data creation program and the print control program of the present invention may be configured by any of OS, APL, OS and APL. In addition to the HD 14, the medium on which these programs and dot type correspondence data are recorded may be a CD-ROM 15a, FD, semiconductor memory, or the like. Further, the communication I / F 17d may be connected to the Internet network, and the program of the present invention may be downloaded from a predetermined server and executed.

  FIG. 3 schematically shows the structure of the dot table 14 b stored in the HD 14. This table 14b is composed of a plurality of dot tables T1 to T3 classified according to gradation sections. The input gradation data indicating the amount of ink used in the printer and the dot formation amount (dot size) for each type of dot. 6 is an information table that defines a correspondence relationship with output gradation data representing (formation amount). The dot table stores the output gradation value D2 in which the dot formation amount in each gradation of the input gradation value D1 constituting the input gradation data is represented for each dot type. Created by the method. The printer driver refers to the dot table, converts the input gradation data after color conversion into output gradation data, and causes the printer to form a plurality of types of dots with different ink amounts using the converted output gradation data. Take control.

FIG. 4 is a flowchart showing the printing control process. When the print execution menu displayed on the display is selected by the APL printing function provided in the APL, the print control program according to the present embodiment is activated to start the print control process.
First, image data composed of gradation data corresponding to a plurality of element colors for each of a large number (predetermined number) of pixels is input and converted into RGB data of 256 gradations in a wide RGB color space (step) S105, hereinafter, “step” is omitted). At this time, data may be partially read, or only a pointer indicating a buffer area used for data transfer may be transferred. The input image data includes data from a digital camera. The image data is data in which an image is expressed by gradation data for each of a number of pixels in a dot matrix, and image data composed of RGB gradation data defined in the sRGB color space, or a YUV table. There are image data composed of YUV gradation data in the color system, and the like. Of course, data conforming to the Exif 2.2 standard (Exif is a registered trademark of the Japan Electronics and Information Technology Industries Association), data corresponding to Print Image Matching (PIM: PIM is a registered trademark of Seiko Epson Corporation), and the like may be used. Since each component of the image data has various gradations, 256 gradations (integer values from 0 to 255) of RGB in the wide-range RGB color space according to the definition of sRGB, YUV color system, etc. To RGB data.

Next, referring to the color conversion LUT while sequentially moving the target pixel using the gradation data of each pixel constituting the RGB data as the conversion target, the gradation data corresponding to the respective usage amounts of the CMYKcm inks. The color is converted into CMYKcm data consisting of (S110). The color conversion LUT stores gradation data for each of CMYKcm and stores it in the HD 14, and includes data corresponding to, for example, each of RGB (17 to the cube of 17) grid points. Then, the RGB data is color-converted into CMYKcm data by referring to the CMYKcm gradation value from the address corresponding to the value of each gradation data constituting the RGB data. If CMYKcm data that matches the input RGB data is not stored in the LUT, CMYKcm data corresponding to a plurality of RGB data close to the input RGB data is acquired and input by an interpolation operation such as volume interpolation. Conversion into CMYKcm data corresponding to RGB data. The CMYKcm data is data in which an image is expressed by gradation data for a large number (predetermined number) of pixels in a dot matrix like RGB data, and the usage amount of each CMYKcm ink discharged from the print head by the printer 20 is expressed. It is assumed that the data is CMYKcm data of 256 gradations (an integer value of 0 to 255).
Note that RGB data and CMYKcm data can have various gradation numbers such as 1024 gradations.

  Then, by moving the target pixel sequentially with the gradation data of each pixel constituting the CMYKcm data as the conversion target, referring to the dot type correspondence data, the gradation for each CMYKcm color constituting the CMYKcm data after color conversion A dot distribution process is performed to convert the data (input gradation data) into dot amount data (output gradation data) representing a plurality of types of dot formation amounts with different ink amounts by the same type (S115). As will be described in detail later, this dot distribution process is a process of distributing the gradation data constituting the CMYKcm data to the usage amounts of a plurality of types of dots.

  After the dot distribution process, a predetermined halftone process such as an error diffusion method and a dither method is performed on the dot amount data for each color and each dot type to binarize the data, and for each color with the same number of pixels as the number of pixels in the CMYKcm data Binarized data for each dot type is generated (S120). The halftone data is data representing the presence or absence of dot formation. For example, the gradation value “1” can correspond to data with dot formation and the gradation value “0” can correspond to data without dot formation.

Further, a predetermined rasterization process is performed on the generated binarized data and rearranged in the order used by the printer to generate raster data for each color (S125). Identification information for identifying the type of dot is added to the raster data. Then, raster data is output to the printer 20 (S130), and the flow ends. Then, the printer 20 obtains raster data representing the image, drives the print head based on these data, forms a plurality of types of dots with different ink amounts on the printing paper, and prints corresponding to the image data. Print an image (output image).
In this way, by referring to the dot type correspondence data, the CMYKcm data is converted into dot amount data for each color and dot type, and the printer is formed with a plurality of types of dots using the converted dot amount data. Control can be performed. If the printer can execute halftone processing, multi-tone CMYKcm data is output to the printer as it is, the dot amount data is generated by referring to the dot type correspondence data, and the dot amount is generated. You may make it print using data.

(2) Creation method and creation process of dot type correspondence data:
FIG. 5 is a flowchart showing processing performed by the dot type correspondence data creating apparatus. In this embodiment, the maximum dot (type 6 in FIG. 2) with the largest ink amount is replaced with a dot of another ink amount to determine the dot formation amount for each type of dot, and for each color of CMYKcm. To process. First, from among the six colors of CMYKcm, the ink color of the data creation target is set by updating the pointer, etc., and for each target ink color, the formation amount (tone value) of each type of dot with different ink amounts and predetermined printing are performed. Correlation data representing the correlation with lightness on the medium is created and displayed as a graph (S205).

FIG. 6 is a graph showing correlation data between the dot formation amount and brightness created for C ink, where the horizontal axis represents the dot formation amount and the vertical axis represents the lightness L (0 ≦ L ≦ 100). The lightness is the lightness in the CIE Lab color space (which may be a CIE Luv color space), which is a uniform color space that does not depend on the device.
The dot formation amount specifies a state in which dots are recorded from a state where each dot is not recorded with a gradation value of 0 to 255 to an upper limit of a duty limit (ink amount limit) per unit area. Each curve of the graph is given a type number corresponding to FIG. The dot formation amount is proportional to the ink recording rate. When the dot formation amount is divided by the maximum gradation value 255, the ink recording rate is obtained. In practice, image data representing patches at each dot formation amount is created for six types of dots, halftone processing and rasterization processing are performed to generate raster data, and output to the printer for predetermined printing. A graph can be created by obtaining the color measurement results of each patch printed on the medium and associating the dot formation amount with the brightness. Here, the operator connects a colorimeter capable of measuring lightness to the PC 10, and presses the colorimeter's detection unit sequentially against each patch to perform color measurement, thereby obtaining the color measurement result on the PC 10. Can be made.

  As shown in the figure, the brightness range of the dots is the narrowest at the smallest dot (type 1) with the smallest ink amount, and becomes wider as the ink amount increases. In each type of dot, the graph is convex downward, and the lightness change rate at the maximum dot is the largest at the low ink formation amount, and the lightness change rate becomes smaller as the ink amount decreases. Colors other than C also show the same tendency although there is a difference in the lightness range.

  Next, a process of determining the number of gradation sections is performed as a pre-stage for dividing the gradation range 0 to 255 that can take the values of gradation data constituting the CMYKcm data into a plurality of gradation sections (S210). For example, when the printing apparatus can form N1 types of dots (N1 is an integer of 3 or more) and N2 types of dots (N2 is an integer of 2 or more and less than N1) correspond to each gradation section, N1 / The maximum integer below (N2-1) can be determined as the number of gradation intervals.

Further, a process for determining a combination of dot types corresponding to each gradation section is performed (S215). In the present embodiment, dot type combinations are determined according to the following rules.
(Rule 1) A plurality of types of dots smaller than the number 6 of dot types that can be formed by the printer are associated with each gradation section. Specifically, three types of dots are associated with each gradation interval.
(Rule 2) A plurality of types of dots that are consecutive in order of ink amount are associated with each gradation interval.
(Rule 3) The plurality of types of dots corresponding to the gradation range on the high gradation side include the types of dots having a larger ink amount than all the types of dots corresponding to the gradation interval on the low gradation side.
(Rule 4) Some of the plurality of types of dots corresponding to each of the gradation sections adjacent to each other in the order of the gradation value among the plurality of gradation sections include the same type of dots.

FIG. 7 schematically shows how six types of dots are associated with each gradation section. In the example of the figure, a state in which the gradation range of 0 to 255 is divided into three gradation intervals in the order of gradation values is shown. This is a gradation interval on the higher gradation side than gradation interval 2. Therefore, the gradation interval 1 can be regarded as the first gradation interval of the present invention, and the gradation intervals 2 and 3 can be regarded as the second gradation interval of the present invention. One gradation interval and gradation interval 3 can be regarded as the second gradation interval. In addition, the state in which the types of dots are arranged in order of the ink amount is also shown, and the ink amount increases as the type number increases.
From the rules 2 and 3, the dots corresponding to the low gradation side are sequentially associated with the dots with the smaller ink amount. According to rule 1, dots of types 1, 2, and 3 that are consecutive in the order of the ink amount are made to correspond to gradation interval 1.
The gradation intervals 1 and 2 are gradation intervals adjacent to each other in the order of gradation values. A part of types 1, 2, and 3 are made to correspond to gradation interval 2 from rule 4, and at least type 4 is made to correspond to gradation interval 2 from rules 2 and 3. First, processing is performed by making two types 2 and 3 and type 4 correspond to the gradation section 2 from the side with the larger ink amount among types 1 and 2 and 3.

The gradation intervals 2 and 3 are adjacent gradation intervals in the order of the gradation values. A part of types 2, 3, and 4 are made to correspond to gradation section 2 from rule 4, and at least type 5 is made to correspond to gradation section 3 from rules 2 and 3. Here, since the gradation section 3 is the gradation section on the highest gradation side, among the types 5 and 6 that do not correspond to the gradation sections 1 and 2, and the types 2, 3 and 4, the ink amount side is large. 1 type 4 corresponds to the gradation interval 3.
If all the types of dots cannot correspond to the gradation interval by the above processing, for example, it corresponds to the gradation range of the intermediate gradation excluding the gradation interval on the lowest gradation side and the gradation interval on the highest gradation side. The process of shifting the types to be performed one by one to the side with the larger ink amount and causing the dot types to correspond to the gradation section on the higher gradation side is repeated.
Through the above processing, all types of dots that can be formed by the printing apparatus can be made to correspond to each gradation section.

  After the completion of S215, the gradation range that can be taken by the gradation data values constituting the CMYKcm data is divided into a plurality of gradation sections (S220). The number of gradation intervals is the number determined in S210. Further, the gradation range is divided by using the correlation data created in S205.

FIG. 6 also schematically shows an example in which the gradation range is divided using the correlation data. For example, correlation data of a type corresponding to a tone interval adjacent on the high tone side is selected from a plurality of types of dots corresponding to each tone interval, and a predetermined dot formation amount Gd is selected from the correlation data. The reference lightness Ld at (0 <Gd <255) is acquired, and the gradation range can be divided by setting the dot formation amount at which the correlation data of the maximum dot is the reference lightness Ld as the boundary of the gradation section. When there are two types of dots corresponding to adjacent gradation intervals on the high gradation side, for example, the lightness Ldi of each dot type at the dot formation amount Gd is averaged to obtain the reference lightness Ld. Of course, the minimum brightness Lmin may be acquired from the selected correlation data and multiplied by a predetermined coefficient greater than 1 to obtain the reference brightness Ld or the like.
In FIG. 7, among the dot types 1, 2, and 3 corresponding to the gradation range 1, the dot types corresponding to the gradation interval 2 adjacent on the high gradation side are the types 2 and 3, so the types 2 and 3 The correlation value is selected, the brightness Ldi for each type is acquired, the average value is set as the reference brightness L1d, and the dot formation amount Gs that becomes the reference brightness L1d is set as the boundary value of the gradation range 1 for the correlation data of the maximum dots. To do. In addition, among the dot types 2, 3, and 4 associated with the gradation interval 2, only the type 4 is associated with the gradation interval 3 that is adjacent on the high gradation side. The reference lightness L2d is obtained by selection, and the dot formation amount Gm that becomes the reference lightness L2d is set as the boundary value of the gradation section 2 for the correlation data of the maximum dots. In the present embodiment, the dot formation amounts Gs and Gm are the upper limit values of the gradation sections 1 and 2, respectively, but may be the lower limit values of the gradation sections 2 and 3 instead of the upper limits of the gradation sections 1 and 2.
Determining the boundary value of the gradation section as described above is useful in that the gradation area can be reliably expressed with the maximum ink amount corresponding to the gradation section. Of course, various brightness values can be adopted as the reference brightness for determining the boundary value of the gradation section using the correlation data, and the minimum brightness Lmin by each type of dot or the maximum brightness by the maximum dot can be used. And a brightness value obtained using the minimum brightness, or a brightness value that divides the brightness range of the maximum dots at equal intervals.

After S220, a target gradation section for creating a dot table is set from a plurality of gradation sections (S225). For example, the target gradation section can be set by updating the value of the pointer corresponding to the gradation section number associated with each gradation section.
Next, the formation amount of each type of dot corresponding to the target gradation section is divided by the parameter X (X> 1) to obtain the parameter Xc that best matches the correlation data of the maximum dot (S230). In the graph of FIG. 6, the dot formation amount is divided by X to match the maximum dot graph.

  FIG. 8 is an explanatory diagram for explaining how the dot formation amount is divided by the parameter X to match the maximum dot graph. Also in this figure, the horizontal axis represents the dot formation amount, the vertical axis represents the lightness L, and the graph before dividing the dot formation amount by the parameter X is indicated by a broken line. When the dot formation amount is divided by X, the broken line on the graph is reduced in the left direction. Therefore, by adjusting X, the brightness change of other dots can be matched with a part of the brightness change of the maximum dot.

The case of dot type 1 corresponding to gradation section 1 will be described. When the brightness change of the dot of type 1 is matched with the brightness change of the maximum dot divided by parameter X1, the dots before and after division at the same brightness value The ratio of the formation amount is a1 · X1: a1 (0 <a1 ≦ Gs). Whether or not they are the best match can be determined by adding the absolute value of the difference in brightness value at each dot formation amount and selecting the value that minimizes the result of the addition. Can determine the parameter Xc.
The above processing is performed for each type of dot corresponding to the gradation interval. That is, since the parameter Xc is acquired for each type of dot corresponding to the gradation interval, in the case of the gradation interval 1, the dot data 1, 2 and 3 most closely match the maximum dot correlation data. The parameters X1c, X2c, and Xc3 are determined. In the case of the gradation section 3, the parameters X4c and X5c that best match the maximum dot correlation data are determined for the dot types 4 and 5, respectively. Since the obtained parameter Xc represents the formation amount of other dots that substitute for the maximum dot, if one maximum dot is replaced with another dot Xc, a replacement that compensates for the difference in the ink amount of the dot is performed. Can do.
Further, the case of the dot type 4 corresponding to the gradation interval 2 will be described. When the brightness change of the dot of type 4 is matched with the brightness change of the maximum dot divided by the parameter X4, before and after division by the same brightness value. The dot formation ratio is a4 · X4: a4 (Gs <a4 ≦ Gm).

  After the end of S230, first, correlation data representing the correlation between the input gradation value and the dot formation amount is created for only the maximum dot (S235). Here, the input gradation value is a gradation value constituting CMYKcm data (input gradation data) after color conversion in which the amount of ink used in the printer is represented, and is a value for each ink color. is there.

FIG. 9 to FIG. 11 are graphs showing the correspondence between the input gradation value and the formation amount of a plurality of types of dots for each gradation section in the case of C ink. In each figure, the horizontal axis represents the input gradation value, and the vertical axis represents the dot formation amount (gradation value). For convenience of illustration, the horizontal axis and the vertical axis have different scales. The information table that defines these correspondences is the dot tables T1 to T3 shown in FIG. 3, and the gradation value on the horizontal axis is the input gradation value D1 of the dot table, and each dot on the vertical axis. Is the output gradation value D2. In the case of MYKcm, a similar graph is obtained, and a similar dot table can be created.
As shown by the broken lines in FIG. 9 to FIG. 11, with the maximum dot alone, when the input gradation value increases linearly (linearly) from 0 to 255, the dot formation amount increases linearly (proportional) from 0 to 255. Correlation data is created as if there is. Therefore, in the gradation section 1, the correlation is a straight line connecting (0, 0) and (Gs, Gs), and in the gradation section 2, the correlation is a straight line connecting (Gs + 1, Gs + 1) and (Gm, Gm). In section 3, the correlation is a straight line connecting (Gm + 1, Gm + 1) and (255, 255).

Thereafter, a process of distributing the maximum dot formation amount to the other dot formation amount is performed for the target gradation interval (S240).
For example, since the dot types 1, 2, and 3 are associated with each other in the gradation section 1, the maximum dots are assigned to the respective types 1, 2, and 3 dots. Here, the input gradation values G1, G2, and G3 that maximize the dot formation amount of each type 1, 2, and 3, for example, from a dot correlation data corresponding to each type, a predetermined dot formation amount Gd (0 The reference lightness Ld at <Gd <255) is acquired, and the dot formation amount at which the correlation data of the maximum dot becomes the reference lightness Ld can be obtained. In this embodiment, the dot formation amount Gd is set so that 0 <G1 <G2 <Gs <G3, and the reference lightness Ld is determined.

In the case of gradation section 1, for type 1 which is the smallest dot, the substitution ratio is determined to be a1 · X1: a1, so the dot formation amount is a1 · X1 with respect to the maximum dot formation amount a1. Since the correlation of only the largest dot indicated by the broken line is a straight line having an inclination 1, the dot of type 1 is a straight line having an inclination X1. Therefore, in the type 1 dot, the input gradation value 0 to G1 is a straight line having an inclination X1, and the input gradation value G1 to G2 is a straight line having an inclination −X1 · G1 / (G2−G1). Here, the input tone value G2 is a tone value at which the formation amount of the type 2 dot having the next largest ink amount after the type 1 dot is maximized. As a result, the maximum dot formation amount becomes 0 from the input gradation value 0 to G1, and the dot formation amount indicated by the double line in the drawing is obtained at the input gradation values G1 to G2.
Next, in the input gradation values G1 to G2, the formation amount of the largest dot (shown by a double line) after the sort of the type 1 dot is replaced with the formation amount of the type 2 dot. Assuming that the substitution ratio of the type 2 dot is a2 · X2: a2, the amount of formation of the type 2 dot is represented by a straight line having an inclination X2 times the inclination G2 / (G2-G1) of the double line in the figure. And Therefore, in the type 2 dot, the input gradation values G1 to G2 are linear with an inclination X2 / G2 / (G2-G1), and the input gradation values G2 to Gs have an inclination -X2 / G2 / (G3-G2). A straight line.
Further, for the input gradation values G2 to Gs, the formation amount of the maximum dot after the sort of the types 1 and 2 is similarly replaced with the formation amount of the type 3 dots. Assuming that the substitution ratio of the type 3 dots is a3 · X3: a3, the input tone values G2 to Gs are straight lines having an inclination X3 · G3 / (G3−G2).

  Note that types 1 and 3 of dots may be mixed and formed. In this case, since the maximum dot formation amount 1 is equivalent to the type 1 and 3 dot formation amounts X1 and X3, the type 3 dot formation amount 1 is replaced by the type 1 dot formation amount X1 / X3. do it. Then, by combining the Type 1 dot, which has a smaller two-step ink amount with the Type 3 dot, in view of the Type 3 dot, it is possible to express a fine area gradation, so that the printed image is further enhanced. Image quality can be improved.

In the gradation section 2, the dot types 2, 3, and 4 are associated with each other, and the input gradation values G2, G3, and G4 that maximize the formation amount of the dots of the respective types 2, 3, and 4 are G2 <Gs <G3. The dot formation amount Gd is set so that <G4 = Gm, and the reference lightness Ld is determined.
Similarly, in the case of gradation interval 2, a straight line representing the correlation is determined. For the type 2 dots, the input gradation values Gs + 1 to G3 are straight lines having an inclination of −X2 · G2 / (G3−G2). For the type 3 dots, the input gradation values Gs + 1 to G3 are linear with an inclination X3 · G3 / (G3−G2), and the input gradation values G3 to Gm (= G4) are inclined −X3 · G3 / (G4− Let G3) be the straight line. In the type 4 dot, the input gradation values G3 to Gm are straight lines having an inclination X4 · G4 / (G4-G3).

In the gradation section 3, the dot types 4, 5, and 6 are associated with each other, and the input gradation values G4, G5, and G6 that maximize the dot formation amount of each type 4, 5, and 6 are G4 = Gm <G5. The dot formation amount Gd is set so that <G6 = 255, and the reference lightness Ld is determined.
Similarly, in the case of gradation zone 3, a straight line representing the correlation is determined. For the type 4 dots, the input gradation values Gm + 1 to G5 are straight lines having an inclination of −X4 · G4 / (G5−G4). For the type 5 dots, the input gradation values Gm + 1 to G5 are straight lines having an inclination of X5 · G5 / (G5 to G4), and the input gradation values G5 to 255 are linear lines having an inclination of −X5 · G5 / (255−G5). To do. Then, the remaining dots are formed with the type 6 dots which are the maximum dots. That is, in the type 6 dot, the input gradation value G5 to 255 is a straight line having an inclination of 255 / (255−G5).
Note that the shapes of the graphs shown in FIGS. 9 to 11 are merely examples, and various modes are conceivable for the peak height, the dot formation range, and the like in each dot type graph. In addition, since the graph of each dot type is only an example, a part or all of the graph can be a curve.

After completion of S240, a dot distribution table for each gradation section is created (S245). 9 to 11 and 3, when the target gradation section is gradation section 1, the corresponding dot table T 1 is associated with each gradation value of input gradation values 0 to Gs. The formation amounts D1 (0) to D1 (Gs), D2 (0) to D2 (Gs), and D3 (0) to D3 (Gs) of types 1, 2 and 3 are stored. When the target gradation interval is gradation interval 2, the dot formation amount D2 (Gs + 1) of the types 2, 3, and 4 corresponding to the input gradation values Gs + 1 to Gm in the corresponding dot table T2 ) To D2 (Gm), D3 (Gs + 1) to D3 (Gm), and D4 (Gs + 1) to D4 (Gm) are stored. When the target gradation section is gradation section 3, the dot formation amount D4 (Gm + 1) of types 4, 5, and 6 is associated with the corresponding dot table T3 corresponding to each gradation value of the input gradation values Gm to 255. ) To D4 (255), D5 (Gm + 1) to D5 (255), and D6 (Gm + 1) to D6 (255).
This determines the correspondence between the input tone data and the output tone data for each dot type for all 256 levels of input tone values from 0 to 255, and the output tone value for each dot type is stored in the dot table. Is done. The created dot table defines the correspondence between input gradation data for each gradation section and output gradation data that represents the formation amount of multiple types of dots in each gradation for each gradation section. Data.

  Thereafter, it is determined whether or not a dot table has been created for all gradation sections (S250). If there are remaining gradation sections for which no dot table has been created, the processes of S225 to S250 are repeated. If a dot table is created for all gradation intervals, it is determined whether a dot table for each gradation interval has been created for all CMYKcm colors (S255). If a color for which a dot table has not been created remains, the processes of S205 to S255 are repeated. If a dot table has been created for all colors, the flow ends.

  Here, the gradation section is divided from a gradation range of 0 to 255 corresponding to each color of CMYKcm ink. This is because the ink density varies depending on the type (color). By dividing the gradation interval according to the ink type, it is possible to form dots of an appropriate type according to the color of the ink, and create dot type data that expresses a higher quality print image It becomes possible to do.

FIG. 12 is an explanatory diagram for explaining that the brightness change characteristic varies depending on the type (color) of ink. This graph is a graph showing the correlation data between the dot formation amount and the brightness created for the maximum dot of CYKc ink, the horizontal axis is the dot formation amount (tone value), and the vertical axis is the lightness L (0 ≦ L ≦ 100). It is. The lightness L is a lightness value defined in the Lab color space. Each curve is a graph of Y, c, C, and K inks from the top. The correlation between the m and c inks is almost the same, and the correlation between the C and M inks is almost the same. As shown in the figure, the lightness with the same dot formation amount becomes smaller as Y, c, C, and K become darker ink. The darker the ink, the wider the lightness range that can be expressed, but the lower the amount of dot formation, the greater the decrease in lightness associated with the increase in the amount of formation, and the smaller the amount of dot formation, the greater the impact on the human eye.
Due to the above ink characteristics, the darker the ink, the more conspicuous the dots become, and it becomes easier to feel a graininess when viewing the printed image. Therefore, the darker the ink, the higher the frequency of use of dots with a small amount of ink in the region where the value of the input gradation data is small. Specifically, as shown in FIG. 13, the gradation interval corresponding to the relatively dark ink is on the high gradation side where more ink is used than the gradation interval corresponding to the relatively thin ink, and the amount of ink is different. The input gradation values G1 to G5, which are the maximum formation amount of each type of dot, are set on the higher gradation side.

In FIG. 13, the K ink gradation interval is higher than the CMYcm ink gradation interval, and the KCM ink gradation interval is higher than the Ycm ink gradation interval. The key interval is on the higher gradation side than the Y ink gradation interval. For all colors, the gradation segment 1 corresponds to the dots of types 1 to 3, the gradation segment 2 corresponds to the dots of types 2 to 4, and the gradation segment 3 corresponds to the dots of types 4 to 6 It corresponds.
That is, when comparing K and CMYcm inks, K ink is the first ink and CMYcm ink is the second ink. When comparing KCM and Ycm inks, KCM ink is the first ink and Ycm. When the ink becomes the second ink and the KCMcm and Y inks are compared, the KCMcm ink becomes the first ink and the Y ink becomes the second ink. Here, the boundary values of the gradation intervals 1 and 2 in each KCcY ink are GKs, GCs, Gcs, GYs (> 0), and the boundary values of the gradation intervals 2 and 3 are GKm (<255), GCm, Gcm, GYm. Then,
GKs>GCs>Gcs> GYs
GKm>GCm>Gcs> GYs
By doing so, the gradation interval becomes higher gradation side as Y, c, C, K.

  FIG. 14 shows the correlation data of the relatively light C ink in the upper stage and the correlation data of the relatively dark K ink in the lower stage for the gradation section 1 on the lowest gradation side. Also in the figure, the horizontal axis represents the dot formation amount, and the vertical axis represents the lightness L. As shown in the figure, the gradation interval 1 is wider on the high gradation side, 0 to GKs for K ink, compared to 0 to GCs for C ink. As a result, assuming that the input gradation values that cause the maximum formation amount in the C ink with respect to the formation amounts of the types 1 and 2 are GC1 and GC2, and the input gradation values that make the maximum formation amount in the K ink the GK1 and GK2. , GC1 <GK1, GC2 <GK2, and the peak of the formation amount of types 1 and 2 can be higher for K ink than for C ink. When the dot formation amount is integrated with the input gradation value for the types 1 and 2 of dots having a relatively small ink amount, the K ink becomes larger than the C ink, and therefore the K ink is relatively ink at the low dot formation amount. The frequency of use of a small amount of dots increases.

  In this way, the gradation interval is divided from the gradation range corresponding to each color ink, and the gradation interval corresponding to the relatively dark first ink is divided into the gradation corresponding to the relatively thin second ink. Since it is on the high gradation side where more ink is used than in the section, when the ink is dark, dots with a smaller amount of ink are more likely to be formed. That is, when the ink is dark, dots with a smaller amount of ink are formed, so that the graininess of the dots becomes inconspicuous, and appropriate types of dots can be formed according to the ink density.

  Through the above processing, the dot tables T1 to T3 for each gradation section are created in gradation sections that are narrower than the gradation range that can be taken by the values of the input gradation data constituting the CMYKcm data after color conversion. Since the number of gradations corresponding to the dot table is reduced, the design for distributing the dots becomes easy. Also, since the printing device creates a dot table that shows the number of dots of a plurality of types that are smaller than the number of types of dots that can be formed on the print medium, it is possible to sort different types of dots with different ink amounts. In this respect, it is possible to distribute the dots by a realistic number of types, and in this respect, it is easy to design how to distribute the dots. In particular, it is easy to distribute three or fewer types of dots. Therefore, it is possible to easily create dot type correspondence data such as a dot distribution table.

Further, among the types of dots that can be formed by the printing device, a plurality of types that are consecutive in the order of the ink amount are associated with each gradation section, so that the dot types that can be formed by the printing device are effectively used. It is possible to create dot type correspondence data that expresses a higher quality print image.
Furthermore, since the types of dots that have a larger amount of ink than the multiple types of dots corresponding to the gradation range on the low gradation side are associated with the gradation region on the higher gradation side, the gradation interval is on the high gradation side. The larger the amount of ink, the more types of dots are included. Accordingly, it is possible to further facilitate the design of dot distribution and to create dot type correspondence data more easily.
Furthermore, since the same type of dot is included in the plurality of types of dots corresponding to each of the adjacent gradation intervals in the order of the gradation value, jumping of area gradation between adjacent gradation intervals is prevented, It is possible to create dot type correspondence data that represents a higher quality print image.
Furthermore, it is possible to create dot type-corresponding data that represents a print image with higher image quality even when the gradation interval is set to a higher gradation side when the ink is dark.

(3) Processing performed by the print control apparatus:
FIG. 15 is a flowchart showing details of the dot distribution process in S115 of FIG. 4 performed by the print control apparatus. When the color conversion process of FIG. 4 is performed to generate CMYKcm data, this flow is started, and a predetermined area for storing the dot amount data subjected to the dot distribution process is secured in the RAM 13 or the like. Data (for example, 0) indicating that dots are not formed is written to all (S305). The area is provided for each color and each dot type.
Next, a target color to be subjected to dot distribution processing is set (S310). For example, the pointer corresponding to the color number corresponding to each color may be updated. Further, target pixels to be subjected to dot distribution processing are set (S315). Even in this process, the pointer corresponding to the pixel number corresponding to each pixel may be updated.

When the target color and the target pixel are set, the gradation data (input gradation data) after color conversion stored in the target pixel is read (S320).
Next, based on the read gradation data, a process for selecting a dot table for reading dot amount data is performed (S325). Referring to FIG. 3, assuming that the read gradation data is a gradation value G (0 ≦ G ≦ 255), for example, a gradation section can be selected as follows.
That is, the minimum value 0 and the maximum value Gs of the input gradation value D1 are read from the dot table T1 corresponding to the gradation section 1, and it is determined whether or not 0 ≦ G ≦ Gs. Select section 1. Further, the minimum value Gs + 1 and the maximum value Gm of the input gradation value D1 are read from the dot table T2 corresponding to the gradation section 2, and it is determined whether or not Gs + 1 ≦ G ≦ Gm. Select section 2. If the gradation sections 1 and 2 are not selected, the gradation section 3 is selected.
Note that a gradation section can be selected by storing the gradation section number in a pointer corresponding to the gradation section number.

When the dot table is selected, the output tone value for each dot type corresponding to the input tone value is read by using the tone value G read in S320 as the input tone value by referring to the dot table (S330). . Then, the output gradation value is stored in the predetermined area in the RAM for each dot type (S335). That is, when the dot table T1 is selected, three types of output gradation values D1 (G), D2 (G), and D3 (G) are read out and stored in the regions corresponding to the dot types 1, 2, and 3, respectively, in the predetermined region. When the dot table T2 is selected, the output gradation values D2 (G), D3 (G), and D4 (G) are read and stored in the areas corresponding to the dot types 2, 3, and 4, respectively, and output when the dot table T3 is selected. The gradation values D4 (G), D5 (G), and D6 (G) are read and stored in the areas corresponding to the dot types 4, 5, and 6, respectively.
In this way, the input gradation data is output for the target pixel by referring to the dot table that defines the correspondence between the gradation sections corresponding to the input gradation data from the dot table defined for each gradation section. It is possible to generate dot amount data by converting into gradation data. As a result, a process for distributing dots is performed by using a dot table for each gradation section.

  Thereafter, it is determined whether or not dot distribution processing has been performed for all pixels (S340). When pixels that have not been processed remain, the processes of S315 to S340 are repeated while sequentially setting the pixels to be processed. When the dot distribution process has been completed for all pixels, it is determined whether the dot distribution process has been performed for all colors (S345). When colors that have not been processed remain, the processes of S310 to S345 are repeatedly performed while sequentially setting the colors to be processed. When the dot distribution process has been completed for all colors, the flow ends.

  Thereafter, the process proceeds to S120 in FIG. 4 to generate binarized data for each color and dot type from the dot amount data for each color and dot type, and to generate raster data from the binarized data in S125. . At this time, identification information for identifying the type of dot is added to the raster data. In step S130, the raster data is transmitted to the printer 20. Then, the printer 20 receives the raster data to which the identification information is added, and forms a plurality of types of dots with different ink amounts on the print medium by forming the types of dots corresponding to the identification information, and print images. To print.

With the above processing, the input tone data is converted into output tone data with reference to the dot table that defines the correspondence between the tone intervals corresponding to the input tone data, and the converted output tone data is used. Thus, it is possible to control the printing apparatus to form a plurality of types of dots.
In this way, a dot type correspondence data device that makes it possible to easily create dot type correspondence data such as a dot distribution table, and the dot type correspondence data for each gradation section created by the method and program are used. Thus, printing control of the printing apparatus can be performed. Therefore, by adopting the printing control apparatus, method and program of the present invention, it is possible to easily create dot type correspondence data.

(4) Various modifications:
By the way, various configurations are possible for the computer and the peripheral device that can be used in carrying out the present invention. For example, the printing apparatus may be integrated with a computer. A printing apparatus that prints only a single color image may be used. A part or all of the above-described flow may be executed by a printing apparatus or a dedicated image processing apparatus.
Moreover, you may make the number of types of dots other than three types correspond to each gradation section.

FIG. 16 is a graph showing the correspondence between the input gradation value and the formation amount of a plurality of types of dots for each gradation section in the case of C ink in the modification.
In this modification, the gradation range is divided into a gradation section 1 of input gradation values 0 to Gs, a gradation section 2 of input gradation values Gs + 1 to Gm, and a gradation section 3 of input gradation values Gm + 1 to 255. , Two types of dot types 1 and 2 are associated with gradation interval 1, three types of dot types 2, 3, and 4 are associated with gradation interval 2, and three types of dots 4, 5, and 6 are associated with gradation interval 3. . A double line is drawn between adjacent gradation intervals. That is, it is possible to associate only two types of dots with the gradation interval. In this case, the dot table has output gradation values representing the formation amounts of only two types of dots corresponding to each input gradation value. Stored. Since it is easy to sort the two types of dots, the dot type correspondence data can be easily created.

Of course, even when four or more types of dots are associated with the gradation section, the dot type correspondence data can be created relatively easily by dividing the gradation range into gradation sections with a smaller number of gradations. If the number of types is smaller than the number of types of dots that can be formed by the printing apparatus, it is possible to obtain an effect that the creation of dot type correspondence data is relatively easy.
Note that the number of types of dots corresponding to the gradation interval may be changed depending on the ink color, and the number of types of dots corresponding to the ink color may be associated with the gradation interval.

In addition, even if a plurality of types that are consecutive in the ink amount order are not associated with each gradation section, dividing the gradation range into a plurality of gradation sections provides an effect that the creation of dot type correspondence data is relatively easy. . Comparison of creation of dot type correspondence data by dividing the gradation range into multiple gradation intervals even if multiple types of dots corresponding to each of the adjacent gradation intervals in order of gradation value do not have the same type of dot The effect which becomes easy to obtain is acquired.
As described above, according to the present invention, it is possible to easily create dot type correspondence data such as a dot distribution table according to various aspects.

1 is a block diagram showing a configuration of a printing system. The figure which expands and shows a nozzle and its internal structure. The figure which shows the structure of a dot table typically. 6 is a flowchart showing print control processing. The flowchart which shows a dot kind corresponding | compatible data creation process. The figure of the graph format which shows the correlation data of dot formation amount and brightness. The figure which shows typically a mode that 6 types of dots are matched with each gradation area. The figure explaining a mode that the formation amount of each kind of dot is matched with the graph of the largest dot. The figure which shows the relationship between the input gradation value and the formation amount of a several kind of dot according to gradation area. The figure which shows the relationship between the input gradation value and the formation amount of a several kind of dot according to gradation area. The figure which shows the relationship between the input gradation value and the formation amount of a several kind of dot according to gradation area. The figure explaining that the brightness change characteristic changes with kinds (color) of ink. The figure which shows typically a mode that 6 types of dots are matched with each gradation area according to a color. The figure which shows that a gradation area is made into the high gradation side, so that ink is dark. The flowchart which shows a dot distribution process. The figure which shows the relationship between the input gradation value and the formation amount of several types of dot for every gradation area in a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Personal computer (PC), 11 ... CPU, 12 ... ROM, 13 ... RAM, 14 ... Hard disk (HD), 14a ... Printer driver, 14b ... Dot allocation table (dot kind correspondence data), 20 ... Inkjet printer, D1 ... input gradation value, D2 ... output gradation value, T1 to T3 ... dot distribution table for each gradation section (dot type correspondence data for each gradation section)

Claims (12)

Input gradation data representing the amount of ink used in a printing device that can form a predetermined number of types of dots with different ink amounts on a print medium, and the amount of dots formed for each gradation for the same type This is a dot type correspondence data creation device that defines a correspondence relationship with output gradation data to be represented and creates dot type correspondence data for reference when converting the same input gradation data into the same output gradation data. There,
The gradation range that the value of the input gradation data can take is divided into a plurality of gradation sections, and the input gradation data and the formation amount of plural types of dots in each gradation are classified into the same kind for each divided gradation section. A dot type correspondence data creating apparatus that creates dot type correspondence data for each gradation section that defines a correspondence relationship with output gradation data to be expressed.   2. The dot type corresponding data creating apparatus according to claim 1, wherein the output gradation data is data representing a plurality of types of dot formation amounts smaller than the predetermined number by the same type. The plurality of gradation sections include at least a first gradation section and a second gradation section on the high gradation side that uses more ink than the first gradation section,
The plurality of types of dots corresponding to the second gradation interval include at least a type of dot having a larger amount of ink than all types of dots corresponding to the first gradation interval. Item 3. The dot type corresponding data creation device according to Item 2.   4. The dot type correspondence data according to claim 3, wherein the plurality of types of dots corresponding to the gradation interval are a plurality of types of dots that are consecutive in order of ink amount among the predetermined number of types of dots. Creation device.   4. The plurality of types of dots corresponding to each of the gradation intervals adjacent to each other in the order of gradation values among the plurality of gradation intervals include a part of the same type of dots. The dot kind corresponding | compatible data preparation apparatus of Claim 4. The printing apparatus can form at least first and second ink dots on the printing medium, and the first ink is darker than the second ink.
The gradation interval is divided from the gradation range corresponding to each of the first and second inks, and the gradation interval corresponding to the first ink corresponds to the second ink. 6. The dot type corresponding data creating apparatus according to claim 3, wherein the dot type corresponding data creating apparatus is on a high gradation side that uses more ink than a gradation section to be used.   7. The plurality of types of dots corresponding to the gradation interval are two or three types of dots among the predetermined number of types of dots. Dot type compatible data creation device. Input gradation data representing the amount of ink used in a printing device that can form a predetermined number of types of dots with different ink amounts on a print medium, and the amount of dots formed for each gradation for the same type This is a dot type correspondence data creation method that defines the correspondence relationship with the output gradation data to be expressed and creates dot type correspondence data for reference when converting the same input gradation data to the same output gradation data. There,
The gradation range that the value of the input gradation data can take is divided into a plurality of gradation sections, and the input gradation data and the formation amount of plural types of dots in each gradation are classified into the same kind for each divided gradation section. A dot type correspondence data creation method, comprising: creating dot type correspondence data for each gradation section that defines a correspondence relationship with output gradation data to be represented. Input gradation data representing the amount of ink used in a printing device that can form a predetermined number of types of dots with different ink amounts on a print medium, and the amount of dots formed for each gradation for the same type Dot that defines the correspondence between the output gradation data to be displayed and allows the computer to implement the function of creating dot type correspondence data for reference when converting the same input gradation data to the same output gradation data A type-compatible data creation program,
The gradation range that the value of the input gradation data can take is divided into a plurality of gradation sections, and the input gradation data and the formation amount of plural types of dots in each gradation are classified into the same kind for each divided gradation section. A dot type correspondence data creation program that realizes a function of creating dot type correspondence data for each gradation section that defines a correspondence relationship with output gradation data to be expressed. Input gradation data representing the amount of ink used in a printing device that can form a predetermined number of types of dots with different ink amounts on a print medium, and the amount of dots formed for each gradation for the same type By referring to the dot type correspondence data that defines the correspondence relationship with the output gradation data to be represented, the same input gradation data is converted to the same output gradation data, and the same printing is performed using the converted output gradation data. A printing control apparatus that controls the apparatus to form a plurality of types of dots,
The dot type correspondence data is the same type as the input tone data and the amount of dots formed in each type of tone for each tone section divided into a plurality of tone ranges that the input tone data can take. It is data that defines the correspondence relationship with the output gradation data expressed separately, for each gradation section,
By referring to the dot type correspondence data defining the correspondence relationship of the gradation intervals corresponding to the input gradation data from among the dot type correspondence data defined for each gradation interval, the input gradation data is converted to the output level. A print control apparatus that converts to tone data and performs print control of the printing apparatus using the converted output gradation data. Input gradation data representing the amount of ink used in a printing device that can form a predetermined number of types of dots with different ink amounts on a print medium, and the amount of dots formed for each gradation for the same type By referring to the dot type correspondence data that defines the correspondence relationship with the output gradation data to be represented, the same input gradation data is converted to the same output gradation data, and the same printing is performed using the converted output gradation data. A printing control method for controlling the apparatus to form a plurality of types of dots,
The dot type correspondence data is the same type as the input tone data and the amount of dots formed in each type of tone for each tone section divided into a plurality of tone ranges that the input tone data can take. It is data that defines the correspondence relationship with the output gradation data expressed separately, for each gradation section,
By referring to the dot type correspondence data defining the correspondence relationship of the gradation intervals corresponding to the input gradation data from among the dot type correspondence data defined for each gradation interval, the input gradation data is converted to the output level. A printing control method comprising: converting to tone data, and performing printing control of the printing apparatus using the converted output gradation data. Input gradation data representing the amount of ink used in a printing device that can form a predetermined number of types of dots with different ink amounts on a print medium, and the amount of dots formed for each gradation for the same type By referring to the dot type correspondence data that defines the correspondence relationship with the output gradation data to be represented, the same input gradation data is converted to the same output gradation data, and the same printing is performed using the converted output gradation data. A print control program for causing a computer to realize a function of performing control for forming a plurality of types of dots in an apparatus,
The dot type correspondence data is the same type as the input tone data and the amount of dots formed in each type of tone for each tone section divided into a plurality of tone ranges that the input tone data can take. It is data that defines the correspondence relationship with the output gradation data expressed separately, for each gradation section,
By referring to the dot type correspondence data defining the correspondence relationship of the gradation intervals corresponding to the input gradation data from among the dot type correspondence data defined for each gradation interval, the input gradation data is converted to the output level. A print control program for converting to tone data and realizing a function of performing print control of the printing apparatus using the output gradation data after conversion.

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