JP2007069615A - Printing method, printing device, printing program, computer readable recording medium, printing device control program, printing device control program, printing device controlling method, data formation device for printing, data generation program for printing, and data formation method for printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing method, etc. which can print an image of multiple gradation (M gradation (M≥3)), without being accompanied by a complicated image processing. <P>SOLUTION: The printing method includes a printing step of printing the image which consists of a plurality of the pixels by delivering a plurality of droplets displaying one tone of multiple gradation (M gradation (M≥3)) with which it should differ in magnitude mutually and each pixel whose each is the plurality of the pixels should express is performed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing method for printing an image by discharging droplet ink, such as printing by an ink jet printer, a printing apparatus using the printing method, a printing program for controlling the printing operation of the printing apparatus, and Printing on a computer-readable recording medium on which the printing program is recorded and a so-called ink jet printing process in which fine particles of liquid ink of a plurality of colors are ejected onto a printing medium, or an ink ribbon coated with solid ink A printing device, printing program, printing method, printing data generation device, printing data suitable for performing a so-called sublimation printing process in which heat is applied by a head to sublimate ink and adhere to a printing medium. The present invention relates to a generation program and a print data generation method.

  In the conventional printing method, a pseudo M (M ≧ 3) gradation (for example, M = 64 (gradation)) is expressed by two gradations (binary) indicating whether or not the droplets are ejected. For example, in order to change the size of dots printed on a printing medium, the amount of droplets is changed, or one dot is formed by discharging a plurality of droplets (hereinafter, referred to as “dots”). A printing method for printing with pseudo M gradations is referred to as a “pseudo multi-gradation printing method”.

  In one conventional printing method related to the above-described pseudo multi-tone printing method, as described in Patent Document 1 below, in order to smoothen between two dots ejected onto a printing medium, that is, In order to improve the graininess, a smaller droplet, that is, a smaller dot is complemented between the two dots. In addition, for example, the distance between dot rows printed by ejecting droplets from a plurality of nozzles arranged in a plurality of rows along the sub-scanning direction is caused by variations in the positions of the plurality of nozzles in the main scanning direction. In order to improve the occurrence of banding in advance, that is, the occurrence of banding in advance, the dots in the dot row that define a relatively wide distance are made large so that the uneven distance is apparently uniform. The amount of the droplet is increased.

Furthermore, in another conventional printing method related to the above-described pseudo multi-tone printing method, as described in Patent Document 2 below, when the content of an image to be printed is a photograph, the photograph is a high definition. When the image to be printed is a character, the image is printed with a large dot so that the character is reproduced clearly, that is, clearly and clearly. .
JP 2002-361909 A JP-A-6-191040

However, in the above-described conventional pseudo multi-gradation printing method, in order to represent a pseudo multi-gradation (M gradation (M ≧ 3)), the dot size as in the above-described one or other conventional printing methods is used. Even if the size is changed, a great amount of time is consumed due to the complexity of the image processing. As a result, there is a problem that it is difficult to actually change the size of the dots.
Therefore, the present invention has been devised to effectively solve such problems, and the object of the present invention is, in particular, multi-gradation (M gradation (M ≧ 3) without complicated image processing). Method, printing apparatus, printing program, computer-readable recording medium, printing apparatus control program, printing apparatus control method, printing data generation apparatus, printing data generation program, and printing data A generation method is provided.

[Mode 1] A printing method according to the present mode is to solve the above-described conventional problems.
The plurality of droplets that are different in size from each other, and each droplet represents one gradation of M gradations (M ≧ 3) that each pixel of the plurality of pixels should represent. A printing step of printing an image composed of the plurality of pixels by ejecting the liquid.
According to the printing method of the present embodiment, the printing step prints an image composed of the plurality of pixels by ejecting the plurality of droplets having different sizes and each representing one gradation. Therefore, an image with M gradations (M ≧ 3) can be reproduced without spending a huge amount of processing time for complicated image processing.

[Mode 2] The printing method according to the present mode is the printing method according to mode 1,
A correction step for correcting the one gradation according to a tone curve that is a base for correcting the one gradation and that defines a relationship between the one gradation before the correction and the one gradation after the correction; Further, the printing step prints one gradation after the correction using a droplet having a size corresponding to the one gradation corrected in the correction step.

[Mode 3] A printing method according to the present mode is the printing method according to mode 2,
The upper or lower limit of the corrected gradation range in the tone curve, or the distance between adjacent pixels after the correction may be caused by the printing of the image. Or a defining step that is defined according to the environment in which the printing apparatus is placed.

[Mode 4] A printing apparatus according to this mode is to solve the above-described conventional problems.
The plurality of droplets that are different in size from each other, and each droplet represents one gradation of M gradations (M ≧ 3) that each pixel of the plurality of pixels should represent. And a printing unit that prints an image composed of the plurality of pixels.

[Mode 5] A printing apparatus according to the present mode is the printing apparatus according to mode 4,
A correction unit that corrects the one gradation according to a tone curve that defines a relationship between the one gradation before the correction and the one gradation after the correction. Further, the printing unit prints one gradation after the correction using a droplet having a size corresponding to the one gradation corrected by the correction unit.

[Mode 6] A printing apparatus according to the present mode is the printing apparatus according to mode 5,
The upper limit or lower limit of the corrected gradation range in the tone curve, or the distance between adjacent pixels after the correction may be caused by the printing of the image. Or a prescribing unit that prescribes according to the environment in which the printing apparatus is placed.

[Mode 7] The printing program according to the present mode is to solve the above-described conventional problems.
The printing unit has a plurality of droplets having different sizes, and each droplet represents one gradation of M gradations (M ≧ 3) that each pixel of the plurality of pixels should represent. A printing step of printing an image composed of the plurality of pixels by discharging a plurality of droplets;

[Mode 8] The printing program according to the present mode is the printing program according to mode 7,
The correction unit serves as a base for correcting the one gradation, and the one gradation is corrected according to a tone curve that defines the relationship between the one gradation before the correction and the one gradation after the correction. A correction step, wherein the printing step uses the droplet having a size corresponding to the one gradation corrected in the correction step to the printing unit to obtain one gradation after the correction. Let it print.

[Mode 9] A printing program according to the present mode is the printing program of mode 8,
The upper or lower limit of the corrected gradation range in the tone curve, or the distance between adjacent pixels after the correction may be caused by the printing of the image. Or a defining step that is defined according to the environment in which the printing apparatus is placed.
[Mode 10] A computer-readable recording medium according to the present mode records the printing program according to any one of modes 7 to 9.

[Mode 11] In order to solve the above-described conventional problems, a printing apparatus according to mode 11 includes:
A print head having a printing element capable of forming a plurality of types of dots respectively corresponding to each gradation of M gradations (M ≧ 3) represented by each pixel constituting the image;
Image data acquisition means for acquiring image data having pixel values representing the gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection means for selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, print data generation means for generating print data defining the type of dot for each pixel value;
And printing means for printing an image of the image data using the print head based on the print data.

  With such a configuration, it is possible to acquire image data having a pixel value representing the gradation of each pixel of the image by the image data acquisition unit, and the dot type selection unit can acquire the image data of the acquired image data. For each pixel value, it is possible to select the type of dot corresponding to the gradation indicated by each pixel value from the plurality of types of dots, and the print data generation unit can select the dot type corresponding to the pixel value. Based on the selection result, it is possible to generate printing data that defines the type of dot for each pixel value, and the image of the image data is printed by the printing unit using the printing head based on the printing data. Can be printed.

  Therefore, for each pixel value of the image data, simply by selecting the type of dot corresponding to each pixel value from among a plurality of types of dots corresponding to each gradation of M gradations (M ≧ 3), From this selection result, it is possible to generate print data that defines the type of dot for each pixel value, and it is possible to print an image of the image data using this print data. There is an effect that a multi-gradation (M gradation (M ≧ 3)) image can be printed without spending time.

  Here, the types of dots include those in which the density is constant and the dot size is different, the dot size is constant and the density is different, and the density and the dot size are different. “No dot (no dot formed)” may be included as one of the types of dots. Hereinafter, a mode related to a printing device control program, a mode related to a printing device control program, a mode related to a printing device control method, a mode related to a printing data control device, a mode related to a printing data generation program, a mode related to a printing data generation method, and an embodiment This is the same in the description of the best mode column for doing so.

  In addition, if there is no dot, the area is not “zero” and has a certain size (area), and there are a plurality of “dots” for each size or density. However, the formed dots are not necessarily perfect circles. For example, when dots are formed in a shape other than a perfect circle such as an ellipse, the average diameter is treated as the dot diameter, or, for example, is equal to the area of a dot formed by ejecting a certain amount of ink. In some cases, an equivalent dot of a perfect circle having an area is assumed, and the diameter of the equivalent dot is treated as the dot diameter. In addition, for example, a method for hitting dots having different densities includes a method of hitting dots having the same dot size and different densities, a method of hitting dots having the same density and different sizes, and ejection of ink having the same density. It is possible to consider a method in which the amount of dots is different and the density is varied by overstrike. In addition, when one ink droplet ejected from one nozzle is separated and landed, it is considered as one dot, but two nozzles or two or more formed from one nozzle around the time. If two dots are stuck, it is assumed that two dots are formed. Hereinafter, a mode related to a printing device control program, a mode related to a printing device control program, a mode related to a printing device control method, a mode related to a printing data control device, a mode related to a printing data generation program, a mode related to a printing data generation method, and an embodiment This is the same in the description of the best mode column for doing so.

  The “image data acquisition unit” acquires image data input from an optical print result reading unit such as a scanner unit, a digital camera, a video camera, or the like, or is connected to an external device via a network such as a LAN or WAN. Acquire stored image data passively or actively, or acquire image data from a recording medium such as a CD-ROM or DVD-ROM via a drive device such as a CD drive or DVD drive of the printing apparatus. The image data stored in the storage device of the printing apparatus is acquired. That is, the acquisition includes at least input, acquisition, reception, and reading. Hereinafter, a mode related to a printing device control program, a mode related to a printing device control program, a mode related to a printing device control method, a mode related to a printing data control device, a mode related to a printing data generation program, a mode related to a printing data generation method, and an embodiment This is the same in the description of the best mode column for doing so.

  In addition, the above-mentioned “specify the dot type for each pixel value” means that “the data format” that can be interpreted by the “printing apparatus” constitutes “information on the type of dot formed for each pixel value”. It is. Hereinafter, a mode related to a printing device control program, a mode related to a printing device control program, a mode related to a printing device control method, a mode related to a printing data control device, a mode related to a printing data generation program, a mode related to a printing data generation method, and an embodiment This is the same in the description of the best mode column for doing so.

[Mode 12] Furthermore, the printing apparatus of mode 12 is the printing apparatus of mode 11,
The plurality of types of dots are configured by a plurality of dots each having a different size corresponding to each of the M gradations.
According to such a configuration, the print head can express each gradation of M gradations in each ink color by dividing the dot size (ink droplet amount), and the dot type selection means Just by selecting the dot type of the size (ink droplet amount) corresponding to each pixel value of the image data, print data specifying the dot type for each pixel value is generated from the selection result, and this printing Since it is possible to print an image of image data by data, it is possible to print a multi-gradation (M gradation (M ≧ 3)) image without spending a huge amount of processing time for complicated image processing. The effect that it can be obtained.

[Mode 13] Further, the printing apparatus of mode 13 is the printing apparatus of mode 11,
The plurality of types of dots are composed of a plurality of dots each having the same size and different print density corresponding to each of the M gradations.
According to such a configuration, the print head can express each gradation of M gradations in each ink color by arranging a plurality of types of dots having the same size but different printing densities. The dot type selection means generates print data that defines the dot type for each pixel value from the selection result simply by selecting the dot type of the print density corresponding to each pixel value of the image data, Since it is possible to print an image of the image data with this printing data, an image with multiple gradations (M gradations (M ≧ 3)) can be printed without spending a huge amount of processing time for complicated image processing. The effect that it can do is acquired.

[Form 14] Furthermore, the printing apparatus of form 14 is the printing apparatus of any one of forms 11 to 13,
The dot type selection means selects a dot type corresponding to a gradation different from the gradation indicated by the pixel value for a predetermined pixel value.
With such a configuration, for example, when the print head can form a plurality of types of dots for each gradation of 256 gradations (M = 256), for example, the pixel values of gradations 72 to 127 are obtained. On the other hand, without selecting the dot types corresponding to these gradations, for example, the dot types corresponding to the gradations 1 to 65 are selected, or conversely, for example, the pixels of gradations 72 to 127 are selected. For example, it is possible to select dot types corresponding to gradations 129 to 184 without selecting dot types corresponding to these gradations.

  By doing this, it is possible to change the tone curve indicating the relationship between the gradation value and the dot type, and in the case of an image where the image of the acquired image data appears to be visually blurry with low contrast, It is possible to obtain an effect that the print image quality can be improved by increasing the contrast of the image and correcting it to a visually clear image.

[Mode 15] Further, the printing apparatus according to mode 15 is the printing apparatus according to any one of modes 11 to 14,
Comprising feature information extraction means for extracting feature information from the acquired image data;
The dot type selecting means corresponds to a gradation different from the gradation indicated by the pixel value for each pixel value having the predetermined content in the characteristic information in the acquired image data based on the extracted characteristic information. The type of dot to be selected is selected.

With such a configuration, the feature information extraction unit can extract the feature information from the image data acquired by the image data acquisition unit, and the dot type selection unit is based on the extracted feature information, It is possible to select a dot type corresponding to a gradation different from the gradation indicated by the pixel value for each pixel value having predetermined content in the feature information in the acquired image data.
Accordingly, for example, by obtaining the image type and the frequency information of the image from the image feature information, it is possible to change the type of dot to be selected to an appropriate one, thereby improving the print image quality. The effect is obtained.

[Mode 16] Further, the printing apparatus of mode 16 is the printing apparatus of mode 15,
Based on the extracted feature information, comprising an image type determining means for determining the type of image of the acquired image data;
The dot type selection unit determines a gradation range of a dot type used for selection processing among a plurality of types of dots respectively corresponding to each of the M gradations based on the determined image type. It is characterized by.

  With such a configuration, it is possible to determine the image type of the acquired image data based on the extracted feature information by the image type determination unit, and the dot type selection unit is Based on the type of the image, it is possible to determine the gradation range of the type of dot used in the selection process among the plurality of types of dots corresponding to the respective gradations of the M gradation.

  Therefore, the gradation range can be changed from a plurality of types of dots corresponding to each of the M gradations according to the type of image. For example, when the type of image is a photographic image, The gradation range is changed so that printing is performed in a gradation range with a small dot size, and a print image with relatively good graininess is formed, for example, the image type is a character image (document image), etc. If this is the case, change the gradation range so that printing is performed in a gradation range with a relatively large dot size, and form a print image with a relatively coarse grain. The gradation range is changed so that a dot type with better graininess is selected for the type of image to be displayed, and the image type that provides a sufficient image quality even if the graininess is somewhat coarse The dot type with coarse graininess Since the gradation range can be changed so that is selected, the gradation range used for selecting the dot type can be easily changed and the image quality can be improved according to the type of image. can get.

[Mode 17] Furthermore, the printing apparatus of mode 17 is the printing apparatus of mode 15,
Printing element characteristic information acquisition means for acquiring printing element characteristic information indicating characteristics of a printing element constituting the print head;
The dot type selection means determines a gradation range of a dot type used for selection processing among a plurality of types of dots respectively corresponding to each of the M gradations based on the acquired printing element characteristic information. It is characterized by.

  If it is such a structure, it is possible to acquire the printing element characteristic information which shows the characteristic of the printing element which comprises the said print head by a printing element characteristic information acquisition means, The said dot kind selection means is the said acquisition Based on the print element characteristic information, it is possible to determine the gradation range of the type of dot used for the selection process among a plurality of types of dots corresponding to the respective gradations of the M gradation.

  Therefore, for example, in the case of an ink jet type print head, the amount of ink ejected by a printing element constituting the print head is reduced in comparison with a normal ink ejection amount due to ink clogging in winter. In this case, for example, by determining the gradation range so as to select a dot having a dot size larger than the dot size corresponding to the gradation indicated by the pixel value, the surrounding environment such as a change in temperature and humidity due to the season etc. Even when the characteristics of the printing element have changed due to changes in the image quality, deterioration over time, etc., the effect that printing can be performed with an appropriate dot type can be obtained.

  Here, “printing element characteristic information acquisition means” is composed of optical printing result reading means such as scanner means, etc., and inspects the ink discharge amount of the printing element from the printing result by the print head, etc. In addition, a configuration for inspecting ink ejection defects using a CCD sensor or the like is also included. In addition, the inspection result information (printing element characteristic information) is stored, for example, together with data at the time of factory shipment or overwriting the data. Hereinafter, a mode related to a printing device control program, a mode related to a printing device control program, a mode related to a printing device control method, a mode related to a printing data control device, a mode related to a printing data generation program, a mode related to a printing data generation method, and an embodiment This is the same in the description of the best mode column for doing so.

[Mode 18] Furthermore, the printing apparatus of mode 18 is the printing apparatus of any one of modes 14 to 17,
When the pixel value is a density value,
The dot type selection unit selects a dot type corresponding to a gradation indicated by a pixel value smaller than the pixel value for the pixel value when the pixel value of the predetermined numerical value is equal to or less than the predetermined pixel value. When the pixel value of the predetermined numerical value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value. Yes.

  With such a configuration, for example, when the print head can form a plurality of types of dots for each gradation of 256 gradations (M = 256), for example, the gradation value is set as a predetermined numerical pixel value. For example, a dot type corresponding to gradations 1 to 65 is selected for pixel values in a range of 72 to 127 (smaller than gradation 128) without selecting dot types corresponding to these gradations. For the pixel values in the range of gradations 129 to 184 (greater than gradation 128), for example, dots corresponding to gradations 194 to 249 are selected without selecting the dot type corresponding to these gradations. It is possible to select the type.

  Therefore, the tone curve indicating the relationship between the gradation value and the dot type can be drawn in an S shape, and in the case of an image in which the image of the acquired image data looks visually blurred with low contrast, The contrast of this image can be increased and corrected to a visually clear image, and when the dot type is a dot size type, the graininess can be improved, thus improving the print image quality. The effect that it can be obtained.

[Mode 19] Furthermore, the printing apparatus of mode 19 is the printing apparatus of any one of modes 14 to 17,
When the pixel value is a density value,
The dot type selection means selects a dot type corresponding to a gradation indicated by a pixel value larger than the pixel value for the pixel value when the pixel value of the predetermined numerical value is smaller than the pixel value. When the pixel value of the predetermined numerical value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. It is said.

With such a configuration, for example, when the print head can form a plurality of types of dots for each gradation of 256 gradations (M = 256), for example, the gradation value is set as a predetermined numerical pixel value. For example, a dot type corresponding to gradations 72 to 127 is selected for pixel values in a range of 1 to 65 (smaller than gradation 128) without selecting dot types corresponding to these gradations. For the pixel values in the range of gradations 194 to 249 (greater than gradation 128), for example, dots corresponding to gradations 129 to 184 are selected without selecting the dot type corresponding to these gradations. It is possible to select the type.
Accordingly, the tone curve indicating the relationship between the gradation value and the dot type can draw an inverse S-shape, and the image of the acquired image data can be corrected to a visually clear image. The effect that the printing image quality can be improved is obtained.

[Mode 20] Furthermore, the printing apparatus according to mode 20 is the printing apparatus according to any one of modes 14 to 17,
The feature information includes frequency information,
When the pixel value is a density value,
The dot type selection unit is configured such that, for each pixel value in which the frequency indicated by the extracted frequency information in the acquired image data is equal to or lower than a predetermined frequency, a predetermined numerical pixel value in each pixel value is based on a predetermined pixel value. Is selected, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value, and a predetermined numerical pixel value in each pixel value is greater than the predetermined pixel value. When the pixel value is large, the dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value.

  With such a configuration, for example, when the print head can form a plurality of types of dots for each gradation of 256 gradations (M = 256) for image data having a relatively low frequency component. In addition, for example, as pixel values having a predetermined numerical value, for pixel values in the range of gradations 72 to 127 (smaller than gradation 128), without selecting dot types corresponding to these gradations, for example, Dot types corresponding to gradations 1 to 65 are selected, and dot types corresponding to these gradations are not selected for pixel values in the range of gradations 129 to 184 (greater than gradation 128). For example, it is possible to select the type of dot corresponding to the gradations 194 to 249.

  That is, an image having a low frequency component is likely to be an image having a low contrast, so that such an image can be easily distinguished, and a tone curve indicating the relationship between the gradation value and the dot type is an S-shape. The dot type can be selected to draw the image, so that the contrast of the low-contrast image can be increased and corrected to a visually clear image, and the dot type is the dot size type In this case, the graininess can be improved, so that the effect of improving the printing image quality can be obtained.

[Mode 21] On the other hand, in order to solve the above-described conventional problems, a printing apparatus control program according to mode 21
Printing used to control a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of M gradations (M ≧ 3) represented by each pixel constituting an image A device control program,
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
And a program used for causing a computer to execute a process including a printing step of printing an image of the image data using the print head based on the printing data.

With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing apparatus of mode 11 are obtained.
In addition, most printing devices on the market such as inkjet printers have a computer system including a central processing unit (CPU), a storage device (RAM, ROM), an input / output device, and the like. Since each means can be realized by software, it can be realized more economically and easily than a case where dedicated means is created to realize each means.
Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 22] Furthermore, the printing apparatus control program according to mode 22 is the same as the printing apparatus control program according to mode 21.
The plurality of types of dots are configured by a plurality of dots each having a different size corresponding to each of the M gradations.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing apparatus of form 12 are obtained.

[Form 23] Furthermore, the printing apparatus control program of form 23 is the printing apparatus control program of form 21,
The plurality of types of dots are composed of a plurality of dots each having the same size and different print density corresponding to each of the M gradations.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing apparatus of form 13 are obtained.

[Mode 24] Further, the printing apparatus control program according to mode 24 is the printing apparatus control program according to any one of modes 21 to 23.
In the dot type selection step, for a predetermined pixel value, a dot type corresponding to a gradation different from the gradation indicated by the pixel value is selected.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing apparatus of form 14 are obtained.

[Mode 25] Further, the printing apparatus control program according to mode 25 is the printing apparatus control program according to any one of modes 21 to 24.
A program used to cause a computer to execute a feature information extraction step of extracting feature information from the acquired image data;
In the dot type selection step, based on the extracted feature information, the feature information has a gradation different from the gradation indicated by the pixel value for each pixel value having a predetermined content in the acquired image data. It is characterized by selecting a corresponding dot type.
With such a configuration, when the program is read by the computer and the computer executes processing according to the read program, the same operation and effect as those of the printing apparatus of form 15 can be obtained.

[Mode 26] Furthermore, the printing apparatus control program of mode 26 is the same as the printing apparatus control program of mode 25.
A program used for causing a computer to execute an image type determination step for determining an image type of the acquired image data based on the extracted feature information;
In the dot type selection step, based on the determined image type, a gradation range of the dot type used in the selection process is determined from among a plurality of types of dots corresponding to the M gradations. It is characterized by that.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing apparatus of form 16 are obtained.

[Mode 27] Furthermore, the printing apparatus control program according to mode 27 is the same as the printing apparatus control program according to mode 25.
Including a program used to cause a computer to execute a printing element characteristic information acquisition step of acquiring printing element characteristic information indicating characteristics of a printing element constituting the printing head;
In the dot type selection step, based on the acquired printing element characteristic information, a gradation range of the dot type used for the selection process is determined from among a plurality of types of dots corresponding to each of the M gradations. It is characterized by that.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing apparatus of form 17 are obtained.

[Mode 28] Further, the printing device control program according to mode 28 is the printing device control program according to any one of modes 24 to 27.
When the pixel value is a density value,
In the dot type selection step, when the pixel value of the predetermined numerical value is equal to or smaller than the predetermined pixel value, the dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. When the predetermined numerical pixel value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value. It is said.
With such a configuration, when the program is read by the computer and the computer executes processing according to the read program, the same operation and effect as those of the printing apparatus of form 18 are obtained.

[Mode 29] Furthermore, the printing device control program according to mode 29 is the printing device control program according to any one of modes 24 to 27.
When the pixel value is a density value,
In the dot type selection step, when the pixel value of the predetermined numerical value is smaller than the predetermined pixel value, the dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is set to the pixel value. When the pixel value of the predetermined numerical value is larger than the predetermined pixel value, the type of the dot corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. It is a feature.
With such a configuration, when the program is read by the computer and the computer executes processing according to the read program, the same operation and effect as those of the printing apparatus of form 19 are obtained.

[Mode 30] Furthermore, the printing device control program according to mode 30 is the printing device control program according to any one of modes 24 to 27.
The feature information includes frequency information,
When the pixel value is a density value,
In the dot type selection step, for each pixel value in which the frequency indicated by the extracted frequency information in the acquired image data is equal to or less than a predetermined frequency, a predetermined numerical pixel value in each pixel value is a predetermined pixel value. If the pixel value is smaller than the pixel value, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected, and a predetermined numerical pixel value in each pixel value is the predetermined pixel value. When it is larger, the type of dot corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing apparatus of form 20 are obtained.

[Mode 31] On the other hand, in order to solve the above-described conventional problems, a printing apparatus control method according to mode 31 includes:
Printing used to control a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of M gradations (M ≧ 3) represented by each pixel constituting an image A device control method comprising:
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
And a printing step of printing an image of the image data using the print head based on the printing data.
Thereby, the same effect as that of the printing apparatus of form 11 is obtained.

[Mode 32] The printing apparatus control method according to mode 32 is the same as the printing apparatus control method according to mode 31.
Printing used to control a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of M gradations (M ≧ 3) represented by each pixel constituting an image A device control method comprising:
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
And a printing step of printing an image of the image data using the print head based on the printing data.
Thereby, the same effect as that of the printing apparatus of form 12 is obtained.

[Mode 33] The printing apparatus control method of aspect 33 is the same as the printing apparatus control method of aspect 31.
The plurality of types of dots are composed of a plurality of dots each having the same size and different print density corresponding to each of the M gradations.
Thereby, the same effect as that of the printing apparatus of form 13 is obtained.

[Form 34] A printing apparatus control method according to form 34 is the printing apparatus control method according to any one of forms 31 to 33.
In the dot type selection step, for a predetermined pixel value, a dot type corresponding to a gradation different from the gradation indicated by the pixel value is selected.
Thereby, the same effect as that of the printing apparatus of form 14 is obtained.

[Mode 35] A printing device control method according to mode 35 is the printing device control method according to any one of modes 31 to 34.
A feature information extraction step for extracting feature information from the acquired image data;
In the dot type selection step, based on the extracted feature information, the feature information has a gradation different from the gradation indicated by the pixel value for each pixel value having a predetermined content in the acquired image data. It is characterized by selecting a corresponding dot type.
Thereby, the same effect as that of the printing apparatus of form 15 is obtained.

[Mode 36] The printing apparatus control method of aspect 36 is the same as the printing apparatus control method of aspect 35,
An image type determining step for determining an image type of the acquired image data based on the extracted feature information;
In the dot type selection step, based on the determined image type, a gradation range of the dot type used in the selection process is determined from among a plurality of types of dots corresponding to the M gradations. It is characterized by that.
Thereby, the same effect as that of the printing apparatus of form 16 is obtained.

[Mode 37] A printing apparatus control method according to mode 37 is the same as the printing apparatus control method according to mode 35.
A printing element characteristic information obtaining step for obtaining printing element characteristic information indicating characteristics of a printing element constituting the print head;
In the dot type selection step, based on the acquired printing element characteristic information, a gradation range of the dot type used for the selection process is determined from among a plurality of types of dots corresponding to each of the M gradations. It is characterized by that.
Thereby, the same effect as that of the printing apparatus of form 17 is obtained.

[Mode 38] A printing device control method according to mode 38 is the printing device control method according to any one of modes 34 to 37.
When the pixel value is a density value,
In the dot type selection step, when the pixel value of the predetermined numerical value is equal to or smaller than the predetermined pixel value, the dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. When the predetermined numerical pixel value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value. It is said.
Thereby, the same effect as that of the printing apparatus of form 18 is obtained.

[Mode 39] A printing device control method according to mode 39 is the printing device control method according to any one of modes 34 to 37.
When the pixel value is a density value,
In the dot type selection step, when the pixel value of the predetermined numerical value is smaller than the predetermined pixel value, the dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is set to the pixel value. When the pixel value of the predetermined numerical value is larger than the predetermined pixel value, the type of the dot corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. It is a feature.
Thus, the same effect as that of the printing apparatus of form 19 is obtained.

[Form 40] The printing apparatus control method according to form 40 is the printing apparatus control method according to any one of forms 34 to 37.
The feature information includes frequency information,
When the pixel value is a density value,
In the dot type selection step, for each pixel value in which the frequency indicated by the extracted frequency information in the acquired image data is equal to or less than a predetermined frequency, a predetermined numerical pixel value in each pixel value is a predetermined pixel value. If the pixel value is smaller than the pixel value, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected, and a predetermined numerical pixel value in each pixel value is the predetermined pixel value. When it is larger, the type of dot corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value.
Thereby, the same effect as that of the printing apparatus of form 20 is obtained.

[Form 41] On the other hand, in order to solve the above-described conventional problems, a print data generation apparatus of form 41 includes:
Printing data used in a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of the M gradations (M ≧ 3) represented by each pixel constituting the image. A print data generation device for generating,
Image data acquisition means for acquiring image data having pixel values representing the gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection means for selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Printing data generation means for generating printing data defining a dot type for each pixel value based on the selection result for each pixel value.

That is, the present embodiment does not include printing means for actually executing printing as in the printing apparatus, but generates printing data based on original multi-value (for example, M value) image data. It is what I did.
Accordingly, it is possible to obtain the same operations and effects as those of the printing apparatus according to the eleventh aspect, and for example, the printing apparatus can execute print processing only by sending the printing data generated in the present embodiment to the printing apparatus. Therefore, with such a configuration, an existing inkjet printing apparatus or an existing sublimation printing apparatus can be used as it is without preparing a dedicated printing apparatus.
In addition, since a general-purpose information processing device such as a personal computer can be used, an existing printing system including a print instruction device such as a personal computer and an inkjet printer can be used as it is.

[Form 42] Furthermore, the print data generation device of form 42 is the print data generation device of form 41,
The plurality of types of dots are configured by a plurality of dots each having a different size corresponding to each of the M gradations.
Thereby, the same operation and effect as those of the printing apparatus of form 12 can be obtained.

[Form 43] Furthermore, the print data generation apparatus of form 43 is the print data generation apparatus of form 41,
The plurality of types of dots are composed of a plurality of dots each having the same size and different print density corresponding to each of the M gradations.
Thereby, the same operation and effect as those of the printing apparatus of form 13 can be obtained.

[Form 44] Furthermore, the print data generation apparatus according to form 44 is the print data generation apparatus according to any one of forms 41 to 43.
The dot type selection means selects a dot type corresponding to a gradation different from the gradation indicated by the pixel value for a predetermined pixel value.
Thereby, the same operation and effect as those of the printing apparatus of form 14 can be obtained.

[Mode 45] Furthermore, the printing data generation device according to mode 45 is the printing data generation device according to any one of modes 41 to 43.
Comprising feature information extraction means for extracting feature information from the acquired image data;
The dot type selecting means corresponds to a gradation different from the gradation indicated by the pixel value for each pixel value having the predetermined content in the characteristic information in the acquired image data based on the extracted characteristic information. The type of dot to be selected is selected.
Thereby, the same operation and effect as those of the printing apparatus of form 15 can be obtained.

[Form 46] Furthermore, the print data generation apparatus of form 46 is the print data generation apparatus of form 45,
Based on the extracted feature information, comprising an image type determining means for determining the type of image of the acquired image data;
The dot type selection unit determines a gradation range of a dot type used for selection processing among a plurality of types of dots respectively corresponding to each of the M gradations based on the determined image type. It is characterized by.
Thereby, the same operation and effect as those of the printing apparatus of form 16 are obtained.

[Form 47] Furthermore, the print data generation apparatus of form 47 is the print data generation apparatus of form 45,
Printing element characteristic information acquisition means for acquiring printing element characteristic information indicating characteristics of a printing element constituting the print head;
The dot type selection means determines a gradation range of a dot type used for selection processing among a plurality of types of dots respectively corresponding to each of the M gradations based on the acquired printing element characteristic information. It is characterized by.
As a result, the same operations and effects as those of the printing apparatus of form 17 are obtained.

[Form 48] Further, the print data generation apparatus according to form 48 is the print data generation apparatus according to any one of forms 44 to 47.
When the pixel value is a density value,
The dot type selection unit selects a dot type corresponding to a gradation indicated by a pixel value smaller than the pixel value for the pixel value when the pixel value of the predetermined numerical value is equal to or less than the predetermined pixel value. When the pixel value of the predetermined numerical value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value. Yes.
Thereby, the same operation and effect as those of the printing apparatus of form 18 are obtained.

[Form 49] Furthermore, the printing data generation apparatus according to form 49 is the printing data generation apparatus according to any one of forms 44 to 47.
When the pixel value is a density value,
The dot type selection means selects a dot type corresponding to a gradation indicated by a pixel value larger than the pixel value for the pixel value when the pixel value of the predetermined numerical value is smaller than the pixel value. When the pixel value of the predetermined numerical value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. It is said.
Thereby, the same operation and effect as those of the printing apparatus of form 19 can be obtained.

[Mode 50] Furthermore, the printing data generation device according to mode 50 is the printing data generation device according to any one of modes 44 to 47.
The feature information includes frequency information,
When the pixel value is a density value,
The dot type selection unit is configured such that, for each pixel value in which the frequency indicated by the extracted frequency information in the acquired image data is equal to or lower than a predetermined frequency, a predetermined numerical pixel value in each pixel value is based on a predetermined pixel value. Is selected, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value, and a predetermined numerical pixel value in each pixel value is greater than the predetermined pixel value. When the pixel value is large, the dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value.
Thereby, the same operation and effect as those of the printing apparatus of form 20 are obtained.

[Form 51] On the other hand, in order to solve the above-described conventional problems, the print data generation program of form 51 is
Printing data used in a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of the M gradations (M ≧ 3) represented by each pixel constituting the image. A print data generation program to be generated,
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
And a program used for causing a computer to execute a process including a printing step of printing an image of the image data using the print head based on the printing data.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operation and effect as those of the printing data generation apparatus of form 41 are obtained.

[Form 52] Furthermore, the print data generation program of form 52 is the same as the print data generation program of form 51,
The plurality of types of dots are configured by a plurality of dots each having a different size corresponding to each of the M gradations.
With such a configuration, when the program is read by the computer and the computer executes processing according to the read program, the same operations and effects as those of the printing data generation apparatus according to form 42 are obtained.

[Form 53] Furthermore, the print data generation program of form 53 is the print data generation program of form 51,
The plurality of types of dots are composed of a plurality of dots each having the same size and different print density corresponding to each of the M gradations.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the print data generating apparatus of form 43 are obtained.

[Form 54] Furthermore, the print data generation program of form 54 is the print data generation program of any one of forms 51 to 53.
In the dot type selection step, for a predetermined pixel value, a dot type corresponding to a gradation different from the gradation indicated by the pixel value is selected.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing data generation apparatus of form 44 are obtained.

[Mode 55] Further, the print data generation program of mode 55 is the print data generation program of any one of modes 51 to 54,
A program used to cause a computer to execute a feature information extraction step of extracting feature information from the acquired image data;
In the dot type selection step, based on the extracted feature information, the feature information has a gradation different from the gradation indicated by the pixel value for each pixel value having a predetermined content in the acquired image data. It is characterized by selecting a corresponding dot type.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the print data generating apparatus of form 45 are obtained.

[Form 56] Furthermore, the print data generation program of form 56 is the print data generation program of any one of forms 51 to 54.
A program used for causing a computer to execute an image type determination step for determining an image type of the acquired image data based on the extracted feature information;
In the dot type selection step, based on the determined image type, a gradation range of the dot type used in the selection process is determined from among a plurality of types of dots corresponding to the M gradations. It is characterized by that.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the print data generating apparatus of form 46 are obtained.

[Mode 57] Furthermore, the print data generation program of mode 57 is the print data generation program of mode 56,
Including a program used to cause a computer to execute a printing element characteristic information acquisition step of acquiring printing element characteristic information indicating characteristics of a printing element constituting the printing head;
In the dot type selection step, based on the acquired printing element characteristic information, a gradation range of the dot type used for the selection process is determined from among a plurality of types of dots corresponding to each of the M gradations. It is characterized by that.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the printing data generation apparatus of form 47 are obtained.

[Form 58] Further, the print data generation program according to form 58 is the print data generation program according to any one of forms 54 to 57.
When the pixel value is a density value,
In the dot type selection step, when the pixel value of the predetermined numerical value is equal to or smaller than the predetermined pixel value, the dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. When the predetermined numerical pixel value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value. It is said.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the print data generating apparatus of form 48 are obtained.

[Form 59] Further, the print data generation program of form 59 is the print data generation program of any one of forms 54 to 57,
When the pixel value is a density value,
In the dot type selection step, when the pixel value of the predetermined numerical value is smaller than the predetermined pixel value, the dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is set to the pixel value. When the pixel value of the predetermined numerical value is larger than the predetermined pixel value, the type of the dot corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. It is a feature.
With such a configuration, when the program is read by the computer and the computer executes processing in accordance with the read program, the same operations and effects as those of the print data generating apparatus of form 49 are obtained.

[Form 60] Furthermore, the print data generation program of form 60 is the print data generation program of any one of forms 54 to 57,
The feature information includes frequency information,
When the pixel value is a density value,
In the dot type selection step, for each pixel value in which the frequency indicated by the extracted frequency information in the acquired image data is equal to or less than a predetermined frequency, a predetermined numerical pixel value in each pixel value is a predetermined pixel value. If the pixel value is smaller than the pixel value, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected, and a predetermined numerical pixel value in each pixel value is the predetermined pixel value. When it is larger, the type of dot corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value.
With this configuration, when the program is read by the computer and the computer executes processing according to the read program, the same operation and effect as those of the printing data generation apparatus according to form 50 can be obtained.

[Form 61] On the other hand, in order to solve the above-described conventional problems, the print data generation method of form 61 includes:
Printing data used in a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of the M gradations (M ≧ 3) represented by each pixel constituting the image. A print data generation method for generating,
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
And a printing step of printing an image of the image data using the print head based on the printing data.
Thus, the same effect as that of the printing data generation apparatus of form 41 is obtained.

[Mode 62] Further, the print data generation method of mode 62 is the same as the print data generation method of mode 61,
Printing used to control a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of M gradations (M ≧ 3) represented by each pixel constituting an image A device control method comprising:
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
And a printing step of printing an image of the image data using the print head based on the printing data.
Thus, the same effect as that of the printing data generation apparatus of form 42 is obtained.

[Mode 63] Furthermore, the printing data generation method of mode 63 is the same as the printing data generation method of mode 61,
The plurality of types of dots are composed of a plurality of dots each having the same size and different print density corresponding to each of the M gradations.
Thereby, the same effect as that of the printing data generation apparatus of form 43 is obtained.

[Mode 64] Furthermore, the printing data generation method of mode 64 is the printing data generation method of any one of modes 61 to 63,
In the dot type selection step, for a predetermined pixel value, a dot type corresponding to a gradation different from the gradation indicated by the pixel value is selected.
Thus, the same effect as that of the printing data generation apparatus of form 44 is obtained.

[Mode 65] Furthermore, the printing data generation method of mode 65 is the printing data generation method of any one of modes 61 to 64,
A feature information extraction step for extracting feature information from the acquired image data;
In the dot type selection step, based on the extracted feature information, the feature information has a gradation different from the gradation indicated by the pixel value for each pixel value having a predetermined content in the acquired image data. It is characterized by selecting a corresponding dot type.
Thus, the same effect as that of the printing data generation apparatus of form 45 is obtained.

[Mode 66] Furthermore, the printing data generation method of mode 66 is the printing data generation method of any one of modes 61 to 64,
An image type determining step for determining an image type of the acquired image data based on the extracted feature information;
In the dot type selection step, based on the determined image type, a gradation range of the dot type used in the selection process is determined from among a plurality of types of dots corresponding to the M gradations. It is characterized by that.
Thus, the same effect as that of the printing data generation apparatus of form 46 is obtained.

[Mode 67] Further, the print data generation method of mode 67 is the same as the print data generation method of mode 65,
A printing element characteristic information obtaining step for obtaining printing element characteristic information indicating characteristics of a printing element constituting the print head;
In the dot type selection step, based on the acquired printing element characteristic information, a gradation range of the dot type used for the selection process is determined from among a plurality of types of dots corresponding to each of the M gradations. It is characterized by that.
Thus, the same effect as that of the printing data generation apparatus of form 47 is obtained.

[Mode 68] Furthermore, the printing data generation method of mode 68 is the printing data generation method of any one of modes 64 to 67,
When the pixel value is a density value,
In the dot type selection step, when the pixel value of the predetermined numerical value is equal to or smaller than the predetermined pixel value, the dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. When the predetermined numerical pixel value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value. It is said.
Thus, the same effect as that of the printing data generation apparatus of form 48 is obtained.

[Mode 69] Furthermore, the printing data generation method of mode 69 is the printing data generation method of any one of modes 64 to 67,
When the pixel value is a density value,
In the dot type selection step, when the pixel value of the predetermined numerical value is smaller than the predetermined pixel value, the dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is set to the pixel value. When the pixel value of the predetermined numerical value is larger than the predetermined pixel value, the type of the dot corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value. It is a feature.
Thus, the same effect as that of the printing data generation apparatus of form 49 is obtained.

[Mode 70] Furthermore, the printing data generation method of mode 70 is the printing data generation method of any one of modes 64 to 67,
The feature information includes frequency information,
When the pixel value is a density value,
In the dot type selection step, for each pixel value in which the frequency indicated by the extracted frequency information in the acquired image data is equal to or less than a predetermined frequency, a predetermined numerical pixel value in each pixel value is a predetermined pixel value. If the pixel value is smaller than the pixel value, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected, and a predetermined numerical pixel value in each pixel value is the predetermined pixel value. When it is larger, the type of dot corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value.
Thereby, the same effect as that of the printing data generating apparatus of form 50 can be obtained.

[Mode 71] On the other hand, in order to solve the above-described conventional problems, a computer-readable recording medium recording the printing apparatus control program according to mode 71 is provided.
A computer-readable recording medium on which the printing apparatus control program according to any one of forms 21 to 30 is recorded.
As a result, the same operation and effect as those of the print data generation program of any one of forms 21 to 30 can be obtained, and the above-described operation can be performed via a recording medium such as a CD-ROM, DVD-ROM, or FD (flexible disk). It is possible to easily exchange printing programs.

[Mode 72] On the other hand, in order to solve the above-described conventional problems, a computer-readable recording medium on which the print data generation program of mode 72 is recorded is as follows.
A computer-readable recording medium on which the printing data generation program according to any one of forms 51 to 60 is recorded.
As a result, the same operations and effects as those of the print data generation program of any one of forms 51 to 60 can be obtained, and the above-described operation can be performed via a recording medium such as a CD-ROM, DVD-ROM, or FD (flexible disk). It is possible to easily exchange printing programs.

[First Embodiment]
A first embodiment of a printing apparatus according to the present invention will be described with reference to the drawings.
"Constitution"
FIG. 1 shows a configuration of a printing apparatus according to the first embodiment, FIG. 2 shows an image to be printed by the printing apparatus according to the first embodiment, and FIG. 3 prints an image according to the first embodiment. FIG. 4 shows nozzles provided in the print head unit of the first embodiment.

  The printing apparatus PRT of the first embodiment includes pixels P (1,1), P (1,2), P (1,3) arranged in a matrix under the control of a computer (including a program). ,. . . Image IMG (shown in FIG. 2), a plurality of print head units PHU (1), (2), (3),. . . (Shown in FIG. 3), eight nozzles N (1), N (2),. . . As shown in FIG. 1, an input unit 10, a processing unit 20, a storage unit 30, and an output unit 40 are provided to print on a medium MED using (shown in FIG. 4).

  Here, regarding the relationship between the pixel P in the image IMG illustrated in FIGS. 1 and 2 and the print head unit PHU and the nozzle N included in the printing apparatus PRT illustrated in FIGS. 3 and 4, for example, the pixel P ( 1, 1) corresponds to the nozzle N (1) of the print head unit PHU (1), and the pixel P (1, 2) corresponds to the nozzle N (2) of the print head unit PHU (1). P (1,3) corresponds to the nozzle N (3) of the print head unit PHU (1), and the pixel P (1,8) corresponds to the nozzle N (8) of the print head unit PHU (1). , P (1, 9) corresponds to the nozzle N (1) of the print head unit PHU (2).

  5 and 6 are diagrams and graphs showing the relationship between the pixel gradation and the dot size. As shown in FIGS. 5 and 6, the pixels P (1,1), P (1,2), P (1,3),. . . Represents M gradations (M ≧ 3), more precisely one gradation out of 64 gradations, and the one gradation is the print head unit PHU (1), PHU (2), PHU ( 3),. . . Nozzles N (1), N (2), N (3),. . . Is displayed by ejecting (printing) dots (droplets) D having a size corresponding to the one gradation onto the medium MED. For example, when the gradation of the pixel P (1, 2) is “gradation 3”, the “gradation 3” is the nozzle N of the print head unit PHU (1) corresponding to the pixel P (1, 1). (2) is printed on the medium MED by ejecting the droplet “size 3”.

  Here, the print head unit PHU supplies ink droplets supplied into ink chambers (not shown) provided for the nozzles N (1), N (2), N (3). The nozzles N (1), N (2), N (3)... Are ejected from the nozzles N (1), N (2), N (3)... By a piezoelectric element such as a piezo actuator (not shown) provided in FIG. Further, by controlling the voltage applied to the piezoelectric element in multiple stages, the ejection amount of ink droplets from the ink chamber is controlled, and each nozzle N (1), N (2), N (3). Dots of different sizes can be printed. In some cases, a voltage is applied to the nozzle in two stages in a short time in a time series, and two dots are combined on the medium MED to form one dot. In this case, by utilizing the fact that the ejection speed varies depending on the size of the dot, by ejecting a large dot followed by a small dot, the ink is landed at substantially the same position on the medium MED to form one larger dot. It is possible to make it.

The input unit 10 includes, for example, a scanner 11, a digital camera 12, a video camera 13, and the like, and converts an image IMG (whether it is a still image or a moving image) into, for example, bitmap data and converts it to the subsequent stage. Used for delivery to the processing unit 20.
The processing unit 20 includes a processing unit 21, a defining unit 22, and a correction unit 23.
The processing unit 21 performs processing on the gradation of the image IMG received from the input unit 10, that is, the resolution and the color expression system (CMYK system, RGB system).

  The defining unit 22 operates as related to the tone curve TC for defining the relationship between the gradation of the pixel P and the size of the dot D as shown in FIG. 6, and more specifically, a plurality of tone curves (FIG. 6, FIG. 12 (A), FIG. 12 (B), etc.), depending on the content of the image IMG (whether it is a natural image, a character string, or a combination of a natural image and a character string). One tone curve TC is selected, or the state of the environment (temperature, humidity, etc.) in which the printing apparatus PRT is placed, or the operating condition of the printing apparatus PRT itself (of droplets from the nozzle) The range to be used (the upper limit or the lower limit of the range) is specified according to the quality of discharge.

  The correction unit 23 determines the size of the dot D corresponding to the gradation of the pixel P according to the tone curve TC selected or defined as described above, that is, adjusts the size of the dot D. More specifically, for example, assuming that the gradation of the pixel P (1,2) is “gradation 8”, the correction unit 23 follows the tone curve TC illustrated in FIGS. When the droplet “size 8” is determined and the tone curve TC illustrated in FIG. 12A is followed, “size 5” is determined, and when the tone curve TC illustrated in FIG. 11 "is determined. That is, based on the information on the size of the dot D for each pixel P, data (printing data) defining the size of the dot D for the gradation value of each pixel P is generated, and the printing data is output to the output unit. 40.

The storage unit 30 temporarily stores the image IMG, and a program PRG (FIG. 8) that defines processing performed by the printing apparatus PRT from a computer-readable recording medium 50 such as a flexible disk or a CD-ROM. Are installed).
The output unit 40 includes, for example, a printer 41, a display (liquid crystal, CRT) 42, and the like. The image IMG after gradation processing and gradation correction based on the tone curve TC by the processing unit 20 is used as a medium MED. Used for printing or displaying. Here, the printer 41 includes a plurality of print head units PHU (1), PHU (2), PHU (3),. . . And print head units PHU (1), PHU (2), PHU (3),. . . Each includes eight nozzles N (1) to N (8) for discharging droplets as shown in FIG.

  FIG. 7 shows a configuration of the computer apparatus. As for the relationship between the printing apparatus PRT shown in FIG. 1 and the general computer apparatus COM shown in FIG. 7, the input unit 10 shown in FIG. 1 includes the input interface 110 shown in FIG. 7, and the processing unit 20 shown in FIG. 7 comprises the CPU 120 of FIG. 7, the storage unit 30 of FIG. 1 comprises the ROM and RAM 130 of FIG. 7, and the output unit 40 of FIG. 1 comprises the output interface 140 of FIG. Yes.

<Operation>
FIG. 8 is a flowchart showing the operation of the printing apparatus according to the first embodiment, and FIG. 9 shows the gradation of the pixels in the image according to the first embodiment. Hereinafter, the operation of the printing apparatus PRT of the first embodiment will be described with reference to the flowchart of FIG. In order to facilitate the explanation and understanding of the operation, as shown in FIG. 9, the pixels P (1,1), P (1,2), P (1,3),. . . , Among the 64 gradations from gradation 1 to gradation 64, gradations 3, 52, 41,. . . Assuming that

Step S10: The user of the printing apparatus PRT inputs the image IMG using the input unit 10.
Step S11: When the image IMG is input, in the processing unit 20, the processing unit 21 converts RGB, which is an additive color system, into CMYK, which is a color mixture system, as is conventionally known for the color system of the image IMG. To do.

Step S12: The processing unit 21 also determines the resolution of the image IMG by the print head units PHU (1), PHU (2), PHU (3),. . . Of the nozzles N (1) to N (8).
Step S13: The correction unit 23 performs the pixel P (1 in the image IMG illustrated in FIG. 9 according to the relationship (tone curve) between the gradation of the pixel P and the size of the dot D illustrated in FIGS. 1) Specify a dot D of “size 3” corresponding to “gradation 3” of 1). Similarly, the correcting unit 23 performs “size 52” dot D corresponding to “gradation 52” of pixel P (1,2) and “gradation 41” corresponding to pixel P (1,3). Dot 41 of size 41 ",. . . Are specified one after another.

  Step S14: The printer 41 places “gradation 3” of the pixel P (1,1), “gradation 52” of the pixel P (1,2), and “floor” of the pixel P (1,3) on the medium MED. Key 41 ",. . . , “Size 3” dot D, “size 52” dot D, “size 41” dot D,. . . , Nozzle N (1) of the print head unit PHU (1), nozzle N (2) of the print head unit PHU (1), nozzle N (3),. . . To print.

"effect"
As described above, in the printing apparatus PRT according to the first embodiment, the correcting unit 23 determines the pixel P (in the image IMG according to the relationship between the gradation of the pixel P and the dot size defined by the defining unit 22. 1, 1), pixel P (1,2), pixel P (1,3),. . . “Size 3” dot D, “size 52” dot D, “size 41” dot D,. . . The printer 41 determines that the designated “size 3” dot D, “size 52” dot D, “size 41” dot D,. . . , Nozzle N (1) of the print head unit PHU (1), nozzle N (2) of the print head unit PHU (1), nozzle N (3),. . . Is printed on the medium MED, the medium MED can display the gradation represented by each pixel P in the image IMG in units of pixels, that is, dots.

  In the first embodiment, the tone curve TC selection process in the defining unit 22 and the correction unit 23 and the process of determining the size of the dot D for each pixel P are the forms 11, 14, 18, 19, 41, 44, The correction unit 23 corresponds to the print data generation unit of the form 11 or 41, and the printer 41 corresponds to the print unit of the form 11.

<Modification 1 of the first embodiment>
Instead of using the relationship between the gradation of the pixel P and the size of the dot D shown in FIGS. 5 and 6, the following alternatives are possible. 10 and 11, there is a possibility that the printing apparatus PRT may print on the medium MED, for example, depending on the atmosphere (temperature, humidity, etc.) in which the printing apparatus PRT is placed. The lower limit and the upper limit are defined from the viewpoint of the quality of ejected droplets, that is, the sizes 1, 2, 3, 62, 63, corresponding to the gradations 1, 2, 3, 62, 63, 64. It is also possible to use the relationship between the gradation of the pixel P and the size of the dot D that the use of 64 is prohibited. As a result, the same effect as described above can be obtained, and the gradation of the dots D printed on the medium MED is different from the input image IMG due to defective ejection of the droplets. It becomes possible to avoid the situation.

In the above-mentioned regulations of the lower limit and the upper limit, it is not necessary to make the number of gradations prohibited to be used the same between the lower limit and the upper limit, and it is not necessary to fix the number of usable gradations. Only the use of the two gradations 1 and 2 is prohibited, and the use of the five gradations 60, 61, 62, 63 and 64 as the upper limit is prohibited, and the number of usable gradations is set to 58 (= 64). The same effect as described above can also be obtained by changing to 32 or 48 without fixing to (3 + 3)).
In the first modification of the first embodiment, the tone curve TC selection process in the defining unit 22 and the correction unit 23 and the process for determining the size of the dot D for each pixel P are forms 11, 14, 17, 18, 19, 41, 44, 47, 48 and 49, the correction unit 23 corresponds to the print data generation unit of the form 11 or 41, and the printer 41 Corresponds to printing means.

<Modification 2 of the first embodiment>
In place of the graph showing the relationship between the gradation of the pixel P and the size of the dot D shown in FIG. 6, an S-shaped correction tone curve as shown in FIG. The contrast of the content of the image IMG printed on the medium MED is increased by increasing the contrast of the content of the image IMG to be printed or, on the contrary, by using an inverted S-shaped correction tone curve as shown in FIG. It can be lowered.

  In the second modification of the first embodiment, the tone curve TC selection process in the defining unit 22 and the correction unit 23 and the process of determining the size of the dot D for each pixel P are the forms 11, 14, 16, 18, 19, 41, 44, 46, 48, and 49, the correction unit 23 corresponds to the print data generation unit of the form 11 or 41, and the printer 41 Corresponds to printing means.

<Modification 3 of the first embodiment>
Instead of the graph showing the relationship between the gradation of the pixel P and the size of the dot D shown in FIG. 6, the following alternatives are possible. That is, when the content of the input image IMG is a natural image (an image having a content corresponding to a photograph), as shown in FIG. 13A, it is more than specified from the relationship shown in FIG. In order to use a small dot D as a whole, for example, for “gradation 8”, the dot D of “size 8” should be used according to the graph of FIG. Although “size 5” dot D is used in accordance with the graph shown in FIG. 13 and “gradation 32”, “size 32” dot D should be used in accordance with the graph of FIG. The dot D of “size” 20 is used according to the graph shown in FIG.

  In contrast, as shown in FIG. 13B, when the content of the image IMG is a character, to use a dot D that is generally larger than specified from the relationship shown in FIG. As for “gradation 8”, “size 14” is used according to the graph shown in FIG. 13B, although “size 8” dot D should be used according to the graph of FIG. For “gradation 32”, “size 42” is used according to the graph shown in FIG. 13B, although the dot D of “size 32” should be used according to the graph of FIG.

  Thus, in addition to being able to obtain the same effect as described above by varying the size corresponding to the gradation depending on whether the image IMG is a natural image or a character, the medium MED Natural images can be printed with high definition, and characters can be printed clearly. Further, when the image IMG includes both a natural image and a character, an intermediate graph between the graph shown in FIG. 13A and the graph shown in FIG. 13B is used. It becomes possible to print a natural image with high definition and print characters clearly.

  In the third modification of the first embodiment, the tone curve TC selection process in the defining unit 22 and the correction unit 23 and the process of determining the size of the dot D for each pixel P are the forms 11, 14, 15, 18, 19, 41, 44, 45, 48, and 49, the correction unit 23 corresponds to the print data generation unit of the form 11 or 41, and the printer 41 Corresponds to printing means.

[Second Embodiment]
Next, a second embodiment of the printing apparatus according to the present invention will be described with reference to the drawings. FIG. 14 is a diagram showing a second embodiment of the printing apparatus according to the present invention.
The configuration of the printing apparatus and the computer apparatus according to the present embodiment is the same as that shown in FIGS. 1 and 7 of the first embodiment. In the present embodiment, the defining unit 22 shown in FIG. 1 extracts feature information from the image IMG, discriminates the contents of the image IMG (natural image, character image, mixture thereof, etc.) based on the feature information, and the discrimination result Is different from the first embodiment in that a tone curve TC used for correction in the correction unit 23 is selected from a plurality of types of tone curves TC. Hereinafter, only different parts from the first embodiment will be described, and description of parts overlapping with the first embodiment will be omitted.

"Constitution"
The defining unit 22 extracts feature information from the image IMG, and based on the extracted feature information, the content of the image IMG (whether it is a natural image, a character image, or a combination of a natural image and a character image) Etc.). Based on the determination result, an appropriate tone curve TC is selected from a plurality of types of tone curves (FIG. 13A, FIG. 13B, etc.).

The image content can be determined by, for example, extracting information indicating the image content previously given to the image IMG file as feature information, or extracting edge information (one of frequency information) using an edge extraction filter. Then, the image content is determined based on the edge information, or the frequency domain information of the image IMG is extracted using Fourier transform, Hadamard transform, or the like, and the image content is determined from the extracted frequency domain information.
The correction unit 23 determines the size of the dot D corresponding to the gradation of the pixel P according to the tone curve TC selected according to the image content as described above, and sets the size of the dot D for each pixel P of the image IMG. Generate specified printing data.

<Operation>
Hereinafter, the operation of the printing apparatus PRT of the second embodiment will be described with reference to the flowchart of FIG. Here, FIG. 14 is a flowchart illustrating the operation of the printing apparatus according to the second embodiment. In order to facilitate the explanation and understanding of the operation, the pixels P (1,1), P (1,2), P (1,3),. . . , Among the 64 gradations from gradation 1 to gradation 64, gradations 8, 64, 32,. . . Assuming that

Step S20: The user of the printing apparatus PRT inputs the image IMG using the input unit 10.
Step S21: When the image IMG is input, in the processing unit 20, the processing unit 21 converts RGB, which is an additive color system, into CMYK, which is a mixed color system, as is conventionally known for the color system of the image IMG. To do.

Step S22: The processing unit 21 also determines the resolution of the image IMG by the print head units PHU (1), PHU (2), PHU (3),. . . Of the nozzles N (1) to N (8).
Step S23: The defining unit 22 also extracts image feature information from the image IMG converted to CMYK. For example, the image content information previously added to the image IMG is extracted, the edge information of the image IMG is extracted using an edge filter, the image signal of the image IMG is subjected to Fourier transform, and the image signal is frequency-converted. It converts into a region and extracts information of the frequency region.

  Step S24: The defining unit 22 also determines the image content based on the extracted feature information. For example, if the extracted information is image content information, it is determined that the image content indicated by the image content information is the image content of the image IMG (natural image, character image, a mixture thereof, or the like). If the extracted feature information is edge information, an edge change or the like is analyzed from the edge information, and the image content is determined based on the analysis result (the feature in which the edge change differs depending on a natural image, a character image, or the like). If the extracted feature information is frequency domain information, the content of the image is determined based on the information represented by each transform coefficient (the transform coefficient indicates a different feature depending on a natural image, a character image, or the like). Use that).

  Step S25: The defining unit 22 also selects a corresponding tone curve TC from a plurality of types of tone curves TC prepared for each image content in accordance with the determined image content. For example, assuming that two types of tone curves TC corresponding to the image contents as shown in FIGS. 13A and 13B are prepared, the image IMG is determined to be a natural image (such as a photographic image). Select a tone curve TC in FIG. 13A using dots in a relatively small size range, and if the image IMG is determined to be a character image (such as a document image), dots in a relatively large size range The tone curve TC shown in FIG. When it is determined that the image IMG is a mixture of a natural image and a character image, a tone curve TC (using a dot in a size range intermediate between the range in FIG. 13A and the range in FIG. 13B) is used. Select (not shown).

Step S <b> 26: The correcting unit 23 determines whether the correction in the image IMG is in accordance with the relationship (tone curve) between the gradation of the pixel P and the size of the dot D illustrated in FIG. 13A or 13 </ b> B. A dot D having a size corresponding to “gradation 8” of the pixel P (1, 1) is designated. Similarly, the correcting unit 23 performs dot D having a size corresponding to “gradation 64” of the pixel P (1, 2) and dot D having a size corresponding to “gradation 32” of the pixel P (1, 3). ,. . . Are specified one after another.
Step S27: The printer 41 sets the gradation value of each pixel P based on the size information of the dot D for each pixel P designated according to the tone curve TC of either FIG. 13 (A) or FIG. 13 (B). On the other hand, print data defining the dot size D is generated, and the image IMG is printed on the medium MED based on the generated print data.

  For example, when the image IMG is a natural image, a dot D having a size corresponding to “gradation 5” is defined with respect to “gradation 8” of the pixel P (1, 1) according to FIG. , A dot D having a size corresponding to “gradation 32” is defined for “gradation 64” of pixel P (1, 2), and “gradation 32” of pixel P (1, 3) is “ A dot D having a size corresponding to “gradation 20” is defined. . . As described above, for each pixel P, print data in which the size of the dot D according to the tone curve TC of FIG. Accordingly, dot D of “size 5”, dot D of “size 32”, dot D of “size 20”,. . . , Nozzle N (1) of the print head unit PHU (1), nozzle N (2) of the print head unit PHU (1), nozzle N (3),. . . To print.

  For example, when the image IMG is a document image, according to FIG. 13B, the dot D having a size corresponding to “gradation 14” with respect to “gradation 8” of the pixel P (1, 1). The dot D having the size corresponding to the “gradation 64” is defined as it is for the “gradation 64” of the pixel P (1, 2), and the “gradation 32” of the pixel P (1, 3) is defined. On the other hand, a dot D having a size corresponding to “gradation 42” is defined. . . As described above, for each pixel P, print data in which the size of the dot D according to the tone curve TC of FIG. 13B is defined is generated. Therefore, dot D of “size 14”, dot D of “size 64”, dot D of “size 42”,. . . , Nozzle N (1) of the print head unit PHU (1), nozzle N (2) of the print head unit PHU (1), nozzle N (3),. . . To print.

"effect"
As described above, in the printing apparatus PRT of the second embodiment, the defining unit 22 extracts feature information from the image IMG, determines the image content of the image IMG based on the extracted feature information, and determines the determined image. Since the tone curve TC is selected according to the content, it is possible to select a tone curve TC suitable for the image content. When the image IMG is a natural image according to the tone curve TC selected in this way, the correction unit 23 selects each pixel P of the image IMG based on the tone curve TC as shown in FIG. Therefore, the printer 41 can print a natural image on the medium MED with high definition.

Further, when the image IMG is a character image, the correction unit 23 determines the size of the dot D for each pixel P of the image IMG based on the tone curve TC as shown in FIG. Thus, it is possible to clearly print a character image on the medium MED.
Further, when the image IMG is a mixed image of a natural image and a character image, the correction unit 23 is intermediate between the tone curve TC illustrated in FIG. 13A and the tone curve TC illustrated in FIG. Since the size of the dot D for each pixel P of the image IMG is determined based on the typical tone curve TC, the printer 41 prints the natural image in the image IMG on the medium MED with high definition and makes the characters clear It becomes possible to print.

  In the second embodiment, the input unit 10 corresponds to the image data acquisition unit in the form 11 or 41, and the feature information extraction processing in the defining unit 22 corresponds to the feature information extraction unit in the form 15 or 45. The image content determination process in the defining unit 22 corresponds to the image type determining unit of form 16 or 46, and the tone curve TC selection process in the defining unit 22 and the correcting unit 23 and the size of the dot D for each pixel P are determined. The processing corresponds to any one of the dot type selection means of forms 11, 14, 15, 16, 41, 44, 45 and 46, and the printing data generation processing in the correction unit 23 is printing of form 11 or 41. The printer 41 corresponds to the printing means according to the eleventh aspect.

[Third Embodiment]
Next, a third embodiment of the printing apparatus according to the present invention will be described with reference to the drawings. FIG. 15 is a diagram showing a third embodiment of a printing apparatus according to the present invention.
The configuration of the printing apparatus and the computer apparatus according to the present embodiment is the same as that shown in FIGS. 1 and 7 of the first embodiment. In the present embodiment, the defining unit 22 shown in FIG. 1 extracts frequency information from the image IMG, and selects a tone curve TC to be used for correction by the correcting unit 23 from a plurality of types of tone curves TC based on the frequency information. Different from the first embodiment. Hereinafter, only different parts from the first embodiment will be described, and description of parts overlapping with the first embodiment will be omitted.

"Constitution"
The defining unit 22 extracts frequency information from the image IMG and, based on the extracted frequency information, an appropriate tone curve among a plurality of types of tone curves (FIG. 12A, FIG. 12B, etc.). Select TC.
For example, the tone curve TC is selected by extracting whether or not the image signal of the image IMG is a high frequency using LPF (low-pass filter) or the like as frequency information, and selecting an appropriate tone curve TC from the extraction result. .
The correction unit 23 determines the size of the dot D corresponding to the gradation of the pixel P according to the tone curve TC selected according to the frequency information as described above, and sets the size of the dot D for each pixel P of the image IMG. Generate specified printing data.

<Operation>
Hereinafter, the operation of the printing apparatus PRT of the third embodiment will be described with reference to the flowchart of FIG. Here, FIG. 15 is a flowchart illustrating the operation of the printing apparatus according to the third embodiment. In order to facilitate the explanation and understanding of the operation, the pixels P (1,1), P (1,2), P (1,3),. . . , Among the 64 gradations from gradation 1 to gradation 64, gradations 8, 64, 32,. . . Assuming that

Step S30: The user of the printing apparatus PRT uses the input unit 10 to input the image IMG.
Step S31: When the image IMG is input, in the processing unit 20, the processing unit 21 converts RGB, which is an additive color system, into CMYK, which is a color mixture system, as is conventionally known for the color system of the image IMG. To do.

Step S32: The processing unit 21 also sets the resolution of the image IMG according to a conventionally known method to the print head units PHU (1), PHU (2), PHU (3),. . . Of the nozzles N (1) to N (8).
Step S33: The defining unit 22 also extracts frequency information from the image IMG converted into CMYK. For example, information indicating whether the image signal is a high frequency is extracted by using LPF or the like for the image signal of the image IMG.

  Step S34: The defining unit 22 selects a corresponding tone curve TC from a plurality of types of tone curves TC prepared in advance according to each frequency range based on the extracted frequency information. For example, assuming that two types of tone curves TC corresponding to frequency contents as shown in FIGS. 12A and 12B are prepared, when the image IMG is a low-frequency image, a relatively low gradation is obtained. In the range, the dot D having a size larger than the size of the dot D corresponding to the actual gradation is designated, and in the relatively high gradation range, the dot D having a size smaller than the size of the dot D corresponding to the actual gradation is selected. When the tone curve TC shown in FIG. 12A is selected and the image IMG is a high-frequency image, the dot D having a size smaller than the size of the dot D corresponding to the actual gradation in a relatively low gradation range. In a relatively high gradation range, the tone curve TC shown in FIG. 12B is selected which specifies a dot D having a size larger than the size of the dot D corresponding to the actual gradation.

Step S35: The correcting unit 23 determines whether or not the image IMG in the image IMG according to the relationship (tone curve) between the gradation of the pixel P and the size of the dot D illustrated in either FIG. 12 (A) or FIG. A dot D having a size corresponding to “gradation 8” of the pixel P (1, 1) is designated. Similarly, the correcting unit 23 performs dot D having a size corresponding to “gradation 64” of the pixel P (1, 2) and dot D having a size corresponding to “gradation 32” of the pixel P (1, 3). ,. . . Are specified one after another.
Step S36: The printer 41 sets the gradation value of each pixel P based on the information of the size of the dot D for each pixel P designated according to the tone curve TC of either FIG. 12 (A) or FIG. 12 (B). On the other hand, print data defining the dot size D is generated, and the image IMG is printed on the medium MED based on the generated print data.

  For example, when the image IMG is a low-frequency image, according to FIG. 12A, a dot D having a size corresponding to “gradation 5” is defined for “gradation 8” of the pixel P (1, 1). The dot D having the size corresponding to the “gradation 64” is defined as it is for the “gradation 64” of the pixel P (1,2), and the “gradation 32” of the pixel P (1,3) is defined as it is. A dot D having a size corresponding to “gradation 38” is defined. . . As described above, print data in which the size of the dot D according to the tone curve TC of FIG. Accordingly, dot D of “size 5”, dot D of “size 64”, dot D of “size 38”,. . . , Nozzle N (1) of the print head unit PHU (1), nozzle N (2) of the print head unit PHU (1), nozzle N (3),. . . To print.

  For example, when the image IMG is a high-frequency image, according to FIG. 12B, the dot D having a size corresponding to “gradation 11” with respect to “gradation 8” of the pixel P (1, 1). The dot D having the size corresponding to the “gradation 64” is defined as it is for the “gradation 64” of the pixel P (1, 2), and the “gradation 32” of the pixel P (1, 3) is defined as it is. On the other hand, a dot D having a size corresponding to “gradation 27” is defined. . . As described above, print data in which the size of the dot D according to the tone curve TC of FIG. 12B is defined for each pixel P is generated. Accordingly, dot D of “size 11”, dot D of “size 64”, dot D of “size 27”,. . . , Nozzle N (1) of the print head unit PHU (1), nozzle N (2) of the print head unit PHU (1), nozzle N (3),. . . To print.

"effect"
As described above, in the printing apparatus PRT of the third embodiment, the defining unit 22 extracts frequency information from the image IMG, and determines whether the image IMG is a high-frequency image or a low-frequency image based on the extracted frequency information. Since the appropriate tone curve TC is selected according to whether the frequency is high or low, the correction unit 23 determines that the image IMG is a low-frequency image (a blurred image) according to the tone curve TC thus selected. In this case, the size of the dot D for each pixel P of the image IMG is determined based on the tone curve TC as shown in FIG. It becomes possible to print.

Further, when the image IMG is a high-frequency image, the correction unit 23 determines the size of the dot D for each pixel P of the image IMG based on the tone curve TC as shown in FIG. Thus, a high-frequency image can be printed on the medium MED in a clear and clear state.
In the third embodiment, the input unit 10 corresponds to the image data acquisition unit in the form 11 or 41, and the frequency information extraction processing in the defining unit 22 corresponds to the feature information extraction unit in the form 15 or 45. The tone curve TC selection process in the defining unit 22 and the correction unit 23 and the process of determining the size of the dot D for each pixel P are forms 11, 14, 15, 16, 18, 19, 20, 41, 44, 45, 46, 48, 49, and 50 corresponds to the dot type selection means, the print data generation processing in the correction unit 23 corresponds to the print data generation means of the form 11 or 41, and the printer 41 This corresponds to the printing means of form 11.

[Fourth Embodiment]
Next, a fourth embodiment of the printing apparatus according to the present invention will be described with reference to the drawings. FIG. 16 is a diagram illustrating a fourth embodiment of a printing apparatus according to the present invention.

  The configuration of the printing apparatus and the computer apparatus of the present embodiment is the same as that of FIGS. 1 and 7 of the second embodiment. In the present embodiment, for example, after the power is turned on, the scanner 11 shown in FIG. 1 reads a test pattern image (solid image) printed by the printer 41, and the nozzle characteristic information generation unit (not shown) of the processing unit 20. Based on the image information read by the scanner 11, the ink ejection state (the presence or absence of density unevenness, etc.) of each nozzle is analyzed, and the analysis result is temporarily stored in the storage unit 30 or the like (for example, until the power is turned off). When the image content is discriminated in the holding unit 22 and the tone curve TC corresponding to the discriminated image content is selected, information on the analysis result of the ink ejection state of each held nozzle (hereinafter, referred to as the tone curve TC) The nozzle characteristic information), and the tone range of the tone curve TC selected based on the acquired nozzle characteristic information is changed. Serial differs from the second embodiment. Hereinafter, only different parts from the second embodiment will be described, and description of parts overlapping with the second embodiment will be omitted.

"Constitution"
The defining unit 22 changes the tone range of the tone curve TC selected according to the image content based on the nozzle characteristic information stored in the storage unit 30.
When the tone range of the tone curve TC is changed, for example, when it is determined that each nozzle is clogged under the influence of changes in the surrounding environment such as temperature and humidity, a relatively small size is set. The gradation range is changed so that a relatively large dot can be easily specified so that the dot range (a range in which ink is not ejected) is not specified.
The correction unit 23 determines the size of the dot D corresponding to the gradation of the pixel P according to the tone curve TC selected based on the ink characteristic information as described above, and sets the size of the dot D for each pixel P of the image IMG. Generate the specified print data.

<Operation>
Hereinafter, the operation of the printing apparatus PRT of the fourth embodiment will be described with reference to the flowchart of FIG. Here, FIG. 16 is a flowchart showing the operation of the printing apparatus of the fourth embodiment. In order to facilitate the explanation and understanding of the operation, the pixels P (1,1), P (1,2), P (1,3),. . . , Among the 64 gradations from gradation 1 to gradation 64, gradations 8, 64, 32,. . . Assuming that

Step S40: The user of the printing apparatus PRT uses the input unit 10 to input the image IMG.
Step S41: When the image IMG is input, in the processing unit 20, the processing unit 21 converts RGB as an additive color system into CMYK as a color mixture system as conventionally known for the color system of the image IMG. To do.

Step S42: The processing unit 21 also determines the resolution of the image IMG by the print head units PHU (1), PHU (2), PHU (3),. . . Of the nozzles N (1) to N (8).
Step S43: The defining unit 22 also extracts image feature information from the image IMG converted to CMYK. For example, the image content information previously added to the image IMG is extracted, the edge information of the image IMG is extracted using an edge filter, the image signal of the image IMG is subjected to Fourier transform, and the image signal is frequency-converted. It converts into a region and extracts information of the frequency region.

  Step S44: The defining unit 22 also determines the image content based on the extracted feature information. For example, if the extracted information is image content information, it is determined that the image content indicated by the image content information is the image content of the image IMG (natural image, character image, a mixture thereof, or the like). If the extracted feature information is edge information, an edge change or the like is analyzed from the edge information, and the image content is determined based on the analysis result (the feature in which the edge change differs depending on a natural image, a character image, or the like). If the extracted feature information is frequency domain information, the content of the image is determined based on the information represented by each transform coefficient (the transform coefficient indicates a different feature depending on a natural image, a character image, or the like). Use that).

Step S45: The defining unit 22 also selects a corresponding tone curve TC from a plurality of types of tone curves TC prepared for each image content in accordance with the determined image content. For example, assuming that two types of tone curves TC corresponding to the image contents as shown in FIGS. 13A and 13B are prepared, the image IMG is determined to be a natural image (such as a photographic image). Select a tone curve TC in FIG. 13A using dots in a relatively small size range, and if the image IMG is determined to be a character image (such as a document image), dots in a relatively large size range The tone curve TC shown in FIG. When it is determined that the image IMG is a mixture of a natural image and a character image, a tone curve TC (using a dot in a size range intermediate between the range in FIG. 13A and the range in FIG. 13B) is used. Select (not shown).
Step S46: The defining unit 22 acquires nozzle characteristic information from the storage unit 30.
Here, the nozzle characteristic information includes, for example, information indicating whether or not density unevenness occurs in the dots formed by each nozzle, information on the average value of the shortage with respect to the actual ink discharge amount of each nozzle, and the like. .

  Step S47: When the average value of the discharge amount of each nozzle is normal based on the acquired nozzle characteristic information, the defining unit 22 leaves the tone range of the tone curve TC selected in step S45 unchanged. On the other hand, when the discharge amount is insufficient, the tone range of the tone curve TC selected in step S45 is changed. Specifically, as described above, since the discharge amount is insufficient (the nozzle is clogged), the selected tone curve TC is, for example, shown in FIG. 13A so that relatively small dots are not formed. ), The dots D having the sizes corresponding to the gradations 0 to 7 of the pixels (dots D corresponding to the dot sizes 0 to 4) are not formed as shown in FIG. The gradation range is changed. On the other hand, for example, when the selected tone curve TC is the one shown in FIG. 13B, as shown in FIG. 17B, the dots D (dots) having the sizes corresponding to the gradations 0 to 7 of the pixels. The gradation range is changed so that dots D) corresponding to sizes 0 to 13 are not formed.

  Step S48: The correction unit 23 is illustrated in any one of FIGS. 13A, 13B, 17A, and 17B after the gradation range changing process. In accordance with the relationship (tone curve) between the gradation of the pixel P and the size of the dot D, the dot D having a size corresponding to “gradation 8” of the pixel P (1, 1) in the image IMG is designated. Similarly, the correction unit 23 performs dot D having a size corresponding to “gradation 64” of the pixel P (1, 2) and dot D having a size corresponding to “gradation 32” of the pixel P (1, 3). ,. . . Are specified one after another.

  Step S49: The printer 41 determines the size of the dot D for each pixel P designated according to the tone curve TC of any one of FIGS. 13A, 13B, 17A, and 17B. Based on the information, print data in which the size of the dot D is defined for the gradation value of each pixel P is generated, and the image IMG is printed on the medium MED based on the generated print data.

  For example, when the image IMG is a natural image and the gradation range is changed, “gradation 12” corresponds to “gradation 8” of the pixel P (1, 1) according to FIG. A dot D having a size is defined, and a dot D having a size corresponding to “gradation 34” is defined with respect to “gradation 64” of the pixel P (1,2). A dot D having a size corresponding to “gradation 24” is defined for “key 32”. . . As described above, print data in which the size of the dot D according to the tone curve TC of FIG. Accordingly, dot D of “size 12”, dot D of “size 34”, dot D of “size 24”,. . . , Nozzle N (1) of the print head unit PHU (1), nozzle N (2) of the print head unit PHU (1), nozzle N (3),. . . To print.

  For example, when the image IMG is a document image and the gradation range is changed, the “gradation 26” is changed from “gradation 8” of the pixel P (1, 1) according to FIG. A dot D having a corresponding size is defined, and a dot D having a size corresponding to “gradation 64” is defined as it is for “gradation 64” of the pixel P (1,2), and the pixel P (1,3) The dot D having a size corresponding to the “gradation 49” is defined for the “gradation 32” of. . . As described above, for each pixel P, print data in which the size of the dot D according to the tone curve TC of FIG. 13B is defined is generated. Accordingly, dot D of “size 26”, dot D of “size 64”, dot D of “size 49”,. . . , Nozzle N (1) of the print head unit PHU (1), nozzle N (2) of the print head unit PHU (1), nozzle N (3),. . . To print.

"effect"
As described above, in the printing apparatus PRT of the fourth embodiment, the defining unit 22 changes the tone range of the selected tone curve TC based on the nozzle characteristic information, and the correcting unit 23 When the image IMG is a natural image and the ink discharge amount of each nozzle is insufficient according to the tone curve TC that has undergone the change processing in this way, the image is based on the tone curve TC as shown in FIG. When the size of the dot D for each pixel P of the IMG is determined and the image IMG is a character image and the ink discharge amount of each nozzle is insufficient, based on the tone curve TC as shown in FIG. Since the size of the dot D for each pixel P of the image IMG is determined, the gradation of the dot D printed on the medium MED due to the droplet ejection failure is larger than that of the input image IMG. It becomes possible to avoid a situation arises in that.

  In the fourth embodiment, the input unit 10 corresponds to the image data acquisition unit of the form 11 or 41, and the nozzle characteristic information acquisition process in the scanner 11 corresponds to the print element characteristic information acquisition unit of the form 17 or 47. The feature information extracting process in the defining unit 22 corresponds to the feature information extracting unit in the form 15 or 45, and the image content determining process in the defining unit 22 corresponds to the image type determining unit in the form 16 or 46. The tone curve TC selection process in the defining unit 22 and the correction unit 23, the process of changing the tone range of the selected tone curve TC based on the nozzle characteristic information, and the process of determining the size of the dot D for each pixel P are as follows: 14, 14, 15, 16, 41, 44, 45, and 46, corresponding to any one of the dot type selection means, the print data in the correction unit 23 is printed. Generating process data corresponds to the print data generation means in the form 11 or 41, the printer 41 corresponds to the printing section in form 11.

  In the first to fourth embodiments, the printer 41 shown in FIG. 1 has a configuration using a so-called ink jet system that prints an image IMG on the medium MED by ejecting ink droplets from the nozzles. As shown in FIG. 18A, in various ink colors, the dots corresponding to the gradations of the ink colors are formed by changing the size of the dots to be formed. The printer 41 may be configured to perform printing using a thermal sublimation method. In this case, as shown in FIG. 18B, the dot size is constant, and dots corresponding to each gradation of each ink color are formed by changing the dot density. In this case, the “dot size” on the vertical axis of the graphs in FIGS. 6, 11, 12, 13, and 17 is “dot density (gradation)”. Further, in the configuration using the ink jet printer 41, for example, light colors of similar colors, such as light magenta for magenta, light cyan for cyan, and a plurality of types of gray inks having different densities, are used. As shown in C), in addition to changing the dot size, the density may be changed to form dots corresponding to each gradation. With such a configuration, a wider gradation can be expressed by a combination of dot size and density.

  In the first to fourth embodiments, the printing apparatus PRT includes the input unit 10, the processing unit 20, and the storage unit 30, and an appropriate tone for the image IMG acquired via the input unit 10. The curve is selected, the size of the dot D is determined for the gradation value of each pixel P in the image IMG, and the printer has a function of generating print data based on the determination result. However, the present invention is not limited to this, and if the printer 41 is separated from the printing apparatus PRT of the first to fourth embodiments, the other functions are general-purpose information processing apparatuses such as personal computers (corresponding to the printing data generation apparatus). It is also possible to realize only with.

FIG. 3 is a diagram illustrating a configuration of a printing apparatus. The figure which shows the image which a printing apparatus should print. The figure which shows the print head unit for printing an image. The figure which shows the nozzle provided in the print head unit. The figure which shows the relationship between the gradation of a pixel, and the size of a dot. The graph which shows the relationship between the gradation of a pixel, and the size of a dot. The figure which shows the structure of a computer apparatus. 6 is a flowchart illustrating the operation of the printing apparatus according to the first embodiment. The figure which shows the gradation of the pixel in the image of 1st Embodiment. The figure which shows the relationship between the gradation of the pixel of the modification 1 of 1st Embodiment, and the size of a dot. The graph which shows the relationship between the gradation of the pixel of the modification 1 of 1st Embodiment, and the size of a dot. The figure which shows the S character correction tone curve and reverse S character correction tone curve of the modification 2 of 1st Embodiment. The figure which shows the relationship between the natural image of the modification 3 of 1st Embodiment, and the size of a dot, and the relationship between a character image and the size of a dot. 6 is a flowchart illustrating an operation of a printing apparatus according to a second embodiment. 10 is a flowchart illustrating an operation of a printing apparatus according to a third embodiment. 10 is a flowchart illustrating an operation of a printing apparatus according to a fourth embodiment. (A) is a figure which shows the relationship between the natural image after a gradation range change, and the size of a dot, (B) is a figure which shows the relationship between a character image and the size of a dot. (A)-(C) are figures which show the variation of a dot kind.

Explanation of symbols

    PRT printing apparatus IMG image MED medium 10 input unit 20 processing unit 30 storage unit 40 output unit 50 recording medium 21 processing unit 22 defining unit 23 correcting unit

Claims (25)

  By ejecting the plurality of droplets that are different in size from each other and each droplet represents one gradation among the multiple gradations that each pixel of the plurality of pixels should represent A printing method comprising a printing step of printing an image composed of the plurality of pixels. A correction step of correcting the one gradation according to a tone curve that is a base for correcting the one gradation and defines a relationship between the one gradation before the correction and the one gradation after the correction; In addition,
2. The printing according to claim 1, wherein the printing step prints one gradation after the correction using a droplet having a size corresponding to the one gradation corrected in the correction step. Printing method.   The upper limit or lower limit of the one gradation range after the correction in the tone curve, or the distance between adjacent pixels after the correction may be caused by the printing of the image. The printing method according to claim 2, further comprising a defining step that is defined according to an environment in which the printing apparatus is placed.   By ejecting the plurality of droplets that are different in size from each other and each droplet represents one gradation among the multiple gradations that each pixel of the plurality of pixels should represent A printing apparatus comprising: a printing unit that prints an image including the plurality of pixels. A correction unit that corrects the one gradation according to a tone curve that defines a relationship between the one gradation before the correction and the one gradation after the correction. In addition,
The said printing part prints one said gradation after the said correction | amendment using the droplet which has a magnitude | size corresponding to the said one gradation corrected by the said correction | amendment part. Printing device.   The upper limit or lower limit of the one gradation range after the correction in the tone curve, or the distance between adjacent pixels after the correction may be caused by the printing of the image. The printing apparatus according to claim 5, further comprising a defining section that is defined according to an environment in which the printing apparatus is placed.   A plurality of droplets, each of which has a size different from each other, and each droplet represents one gradation among the multiple gradations to be represented by each pixel of the plurality of pixels. A printing program comprising a printing step of printing an image composed of a plurality of pixels by discharging. The correction unit serves as a base for correcting the one gradation, and the one gradation is corrected according to a tone curve that defines a relationship between the one gradation before the correction and the one gradation after the correction. A correction step for
The printing step causes the printing unit to print one gradation after the correction using a droplet having a size corresponding to the one gradation corrected in the correction step. The printing program according to claim 7.   The upper limit or lower limit of the one gradation range after the correction in the tone curve, or the distance between adjacent pixels after the correction may be caused by the printing of the image. 9. The printing program according to claim 8, further comprising a defining step that is defined according to an environment in which the printing apparatus is placed.   A computer-readable recording medium in which the printing program according to any one of claims 7 to 9 is recorded. A print head having a printing element capable of forming a plurality of types of dots respectively corresponding to each gradation of M gradations (M ≧ 3) represented by each pixel constituting the image;
Image data acquisition means for acquiring image data having pixel values representing the gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection means for selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, print data generation means for generating print data defining the type of dot for each pixel value;
A printing apparatus comprising: a printing unit that prints an image of the image data using the print head based on the printing data.   The printing apparatus according to claim 11, wherein the plurality of types of dots are composed of a plurality of dots of different sizes respectively corresponding to the M gradations.   12. The printing apparatus according to claim 11, wherein the plurality of types of dots are composed of a plurality of dots each having the same size and different print density corresponding to each of the M gradations.   The dot type selection unit selects a dot type corresponding to a gradation different from the gradation indicated by the pixel value for a predetermined pixel value. The printing apparatus according to any one of the above. Comprising feature information extraction means for extracting feature information from the acquired image data;
The dot type selecting means corresponds to a gradation different from the gradation indicated by the pixel value for each pixel value having the predetermined content in the characteristic information in the acquired image data based on the extracted characteristic information. The printing apparatus according to claim 11, wherein the type of dot to be selected is selected. Based on the extracted feature information, comprising an image type determining means for determining the type of image of the acquired image data;
The dot type selection unit determines a gradation range of a dot type used for selection processing among a plurality of types of dots respectively corresponding to each of the M gradations based on the determined image type. The printing apparatus according to claim 15. Printing element characteristic information acquisition means for acquiring printing element characteristic information indicating characteristics of a printing element constituting the print head;
The dot type selection means determines a gradation range of a dot type used for selection processing among a plurality of types of dots respectively corresponding to each of the M gradations based on the acquired printing element characteristic information. The printing apparatus according to claim 15 or 16, characterized in that: When the pixel value is a density value,
When the pixel value of the predetermined numerical value is smaller than the predetermined pixel value, the dot type selection unit selects a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value with respect to the pixel value. When the predetermined numerical pixel value is larger than the predetermined pixel value, a dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value. The printing apparatus according to any one of claims 14 to 17. When the pixel value is a density value,
The dot type selection unit selects a dot type corresponding to a gradation indicated by a pixel value larger than the pixel value for the pixel value when the pixel value of the predetermined numerical value is smaller than the pixel value. When the predetermined numerical pixel value is larger than the predetermined pixel value, a dot type corresponding to a gradation indicated by a pixel value smaller than the pixel value is selected for the pixel value. The printing apparatus according to any one of claims 14 to 17. The feature information includes frequency information,
When the pixel value is a density value,
The dot type selection unit is configured such that, for each pixel value in which the frequency indicated by the extracted frequency information in the acquired image data is equal to or less than a predetermined frequency, a predetermined numerical pixel value in each pixel value is greater than a predetermined pixel value. Is selected, a dot type corresponding to the gradation indicated by the pixel value smaller than the pixel value is selected for the pixel value, and a predetermined numerical pixel value in each pixel value is greater than the predetermined pixel value. The dot type corresponding to the gradation indicated by the pixel value larger than the pixel value is selected for the pixel value when the pixel value is larger. The printing apparatus as described. Printing used to control a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of M gradations (M ≧ 3) represented by each pixel constituting an image A device control program,
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
A printing apparatus control program comprising: a program used for causing a computer to execute a process including a printing step of printing an image of the image data using the print head based on the printing data. Printing used to control a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of M gradations (M ≧ 3) represented by each pixel constituting an image A device control method comprising:
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
And a printing step of printing an image of the image data using the print head based on the printing data. Printing data used in a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of the M gradations (M ≧ 3) represented by each pixel constituting the image. A print data generation device for generating,
Image data acquisition means for acquiring image data having pixel values representing the gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection means for selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
A printing data generation device, comprising: printing data generation means for generating printing data defining a dot type for each pixel value based on the selection result for each pixel value. Printing data used in a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of the M gradations (M ≧ 3) represented by each pixel constituting the image. A print data generation program to be generated,
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
A printing data generation program comprising: a program used for causing a computer to execute a process including a printing step of printing an image of the image data using the printing head based on the printing data. Printing data used in a printing apparatus having a print head having a printing element capable of forming a plurality of types of dots corresponding to each of the M gradations (M ≧ 3) represented by each pixel constituting the image. A print data generation method for generating,
An image data acquisition step of acquiring image data having a pixel value representing a gradation of each pixel of the image;
For each pixel value of the acquired image data, a dot type selection step of selecting a dot type corresponding to the gradation indicated by each pixel value from the plurality of types of dots,
Based on the selection result for each pixel value, a print data generation step for generating print data defining a dot type for each pixel value;
And a printing step for printing an image of the image data using the print head based on the printing data.

Images