JP2004291459A - Image processor, method, program, recording medium, and image output device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor capable of preventing variation in printing by reducing granularity of an image printed on a medium by inkjet printing, a method, a program, and a recording medium, and an image output device. <P>SOLUTION: In this image processor, quantities of ink to be used are determined when printing is performed by using two or more kinds of the ink having different densities for at least one identical hue. The image processor comprises a different density ink using quantity recording means that performs the recording by correlating the quantities of the different kinds of ink with gradation image data of each pixel. In the recorded content, the sum of the quantities of the used ink exceeds a linear quantity of the ink obtained by proportionating the sum with gradation over the whole range of the gradation of the gradation image data. The image processor further comprises a different density ink use quantity determining means that determines the quantities of the ink to be used corresponding to the gradation image data based on the recorded content of the different density ink using quantity recording means by receiving the gradation image data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to preventing color unevenness in an ink jet printer.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, printers having an inkjet head have been widely used. In such a printer, dots of two sizes, large and small, may be printed, or two types of inks of dark and light may be used (for example, see Patent Documents 1, 2, and 3).
[0003]
When using two types of dark and light inks, a large amount of dark ink is used when printing a deep color image, and a large amount of light ink is used when printing a light image. For example, it is assumed that the input data takes a value of 0 to 255. Here, when the input data has a high gradation of 191 (dark image), no light ink is used at all (for example, see FIG. 18 of Patent Document 3).
[Patent Document 1]
JP 2002-185790 A [Patent Document 2]
JP-A-11-348322 [Patent Document 3]
JP 10-44475 A [Problems to be Solved by the Invention]
By the way, in order to reduce the granularity of an image printed on a medium, it is conceivable to print dots of a smaller size. However, the smaller the dot size, the greater the effect of the displacement of the landing position of the dot that has landed on the medium on the image quality. For example, the landing positions of dots may periodically shift due to the vibration of the inkjet head. As a result, a pattern (unevenness, white stripes) may be seen when viewing the print result on the medium. This pattern is also noticeable as the dot size is smaller.
[0004]
Therefore, an object of the present invention is to prevent printing unevenness while reducing the granularity of an image printed on a medium by an inkjet method.
[0005]
[Means for Solving the Problems]
The invention according to claim 1 is an image processing apparatus for determining the amount of ink used when printing is performed using two or more types of inks having different densities for at least one hue, and The gradation image data is recorded in association with the usage amounts of the various inks, and the recorded content is such that the sum of the ink usage amounts is almost equal to the sum of the ink usage amounts in almost the entire range of the gradation of the gradation image data. Receives the gradation image data, which exceeds the linear ink amount proportional to the gradation, and receives the gradation image data, and corresponds to the gradation image data based on the recording contents of the gradation ink consumption recording unit. And a dark and light ink usage determining means for determining the used amount of ink.
[0006]
According to the invention configured as described above, there is provided an image processing apparatus for determining the amount of ink used when printing is performed using two or more types of inks having different densities for at least one hue. .
[0007]
This image processing apparatus includes a density ink usage amount recording unit and a density ink usage amount determination unit. The density ink usage recording means records the gradation image data for each pixel in association with the usage of various inks, and the recorded content is such that the sum of the ink usage is the gradation of the gradation image data. In almost the entire region, the sum of the ink usage exceeds the linear ink amount proportional to the gradation. The density ink usage determining means receives the gradation image data, and determines the ink usage corresponding to the gradation image data based on the recording content of the density ink usage recording means.
[0008]
The invention according to claim 2 is the invention according to claim 1, wherein the linear ink amount is configured to take the maximum ink amount usable for a print medium at the highest gradation of the gradation image data. .
[0009]
According to a third aspect of the present invention, in the first aspect of the invention, the recording content of the dark and light ink use amount recording means is such that the amount of the lightest lightest ink in the ink is the gradation of the gradation image data. And the minimum value of the lightest ink amount in the lightest ink amount decreasing region is configured to exceed zero.
[0010]
A fourth aspect of the present invention is the invention according to the first aspect, wherein the density that can be expressed only by the deepest ink among the inks is less than the density corresponding to the highest tone of the tone image data. It is configured to be.
[0011]
The invention according to claim 5 is the invention according to claim 1, wherein the recording content in the density ink usage recording means is the lightest ink among the inks as the gradation of the gradation image data increases. It is configured to include a lightest ink amount horizontal area in which the amount of light ink has a substantially constant maximum value.
[0012]
The invention according to claim 6 is the invention according to claim 1, wherein the recording content of the light and dark ink use amount recording means is such that the rate at which the amount of the lightest lightest ink in the ink increases is linear ink. It is configured to include the lightest ink amount increase region that is larger than the rate at which the amount increases.
[0013]
According to a seventh aspect of the present invention, there is provided an image processing method for determining the amount of ink used when printing is performed using two or more types of inks having different densities for at least one hue. The gradation image data is recorded in association with the usage amounts of the various inks, and the recorded content is such that the sum of the ink usage amounts is almost equal to the sum of the ink usage amounts in almost the entire range of the gradation of the gradation image data. Receives the gradation image data and the gradation image data that exceeds the linear ink amount proportional to the gradation, and corresponds to the gradation image data based on the recording contents in the gradation ink consumption recording process. And a density ink use amount determining step of determining the used amount of the used ink.
[0014]
According to an eighth aspect of the present invention, there is provided an image processing apparatus for causing a computer to execute image processing for determining the amount of ink used when printing is performed using two or more types of inks having different densities for at least one hue. The program records the gradation image data for each pixel in association with the amount of use of various inks, and the recorded content is such that the sum of the amount of ink used is substantially equal to the entire gradation of the gradation of the gradation image data. In the dark and light ink usage amount recording process that exceeds the linear ink amount in which the sum of the ink usage amount is proportional to the gradation, This is a program for causing a computer to execute a dark and light ink use amount determining process for determining an ink use amount corresponding to the gradation image data.
[0015]
According to a ninth aspect of the present invention, there is provided a computer-readable recording medium storing the program according to the eighth aspect.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a block diagram of an image processing system to which an image processing control method according to an embodiment of the present invention is applied, and FIG. 2 is a schematic block diagram illustrating a specific hardware configuration example of the image processing apparatus. I have.
[0018]
In FIG. 1, an image processing apparatus 20 performs image processing on color image data supplied from an image input apparatus 10 and outputs the processed color image data to an image output apparatus (for example, a color printer 17b). I do. Here, the color image data represents the strength of each element color while separating the color image for each predetermined element color, and is represented by gray when it is a chromatic color and mixed at a predetermined ratio. Color and black.
[0019]
The image processing device 20 includes a color conversion unit 20a, a dark and light ink usage recording unit 20b, a dark and light ink usage determination unit 20c, a dot rate recording unit 20d, a light ink dot ratio determination unit 20e, a dark ink dot ratio determination unit 20f, It includes a usage recording unit 20p, an ink usage determining unit 20q, and a dot rate determining unit 20r. Details of each part will be described later.
[0020]
Hardware Configuration Example FIG. 2 is a schematic block diagram illustrating a specific hardware configuration example of the image processing apparatus 20. In the embodiment, a computer system is employed as an example of hardware for realizing the image processing apparatus. FIG. 2 is a block diagram showing the computer system. The computer system includes a scanner 11a, a digital still camera 11b, and a video camera 11c as image input devices, and is connected to the computer main body 12. Each input device can generate color image data representing an image by dot matrix pixels and output the color image data to the computer main unit 12, where the image data is displayed in 256 gradations in three primary colors of RGB. Thus, about 16.7 million colors can be expressed.
[0021]
The computer main body 12 is connected to a floppy disk drive 13a, a hard disk 13b, and a CD-ROM drive 13c as external auxiliary storage devices. The hard disk 13b stores main programs related to the system. Necessary programs and the like can be appropriately read from a CD-ROM or the like. Also, a modem 14a is connected as a communication device for connecting the computer main body 12 to an external network or the like. The modem 14a is connected to the external network via the same public communication line, and software and data can be downloaded and introduced. Has become. In this example, the modem 14a accesses the outside through a telephone line. However, a configuration in which a network is accessed through a LAN adapter is also possible. In addition, a keyboard 15a and a mouse 15b for operating the computer main body 12 are also connected.
[0022]
Further, a display 17a, a color printer 17b, and a projector 17c are provided as image output devices. The display 17a has a display area of 800 pixels in the horizontal direction and 600 pixels in the vertical direction, and can display the above-mentioned 16.7 million colors for each pixel. This resolution is merely an example, and can be changed as appropriate, such as 640 × 480 pixels or 1024 × 768 pixels.
[0023]
The color printer 17b is an ink jet printer, and uses six color inks of C (cyan), M (magenta), Y (yellow), K (black), c (light cyan), and m (light magenta) on a printing paper as a medium. An image can be printed by adding a dot to. The image density can be printed at a high density such as 360 × 360 dpi or 720 × 720 dpi, but the gradation expression is a two gradation expression such as whether or not to apply color ink. On the other hand, a predetermined program is executed in the computer main body 12 in order to display or output an image output device while inputting an image using such an image input device. Of these, an operating system (OS) 12a that operates as a basic program includes a display driver (DSP DRV) 12b for performing display on a display 17a, and print output to a color printer 17b. A printer driver (PRT DRV) 12c for performing the display and a projector driver 12d (not shown) for displaying on the projector 17c are incorporated. These drivers 12b, 12c and 12d depend on the models of the display 17a, the color printer 17b and the projector 17c, and can be added to the operating system 12a in accordance with the respective models. In addition, additional functions beyond standard processing can be realized depending on the model. That is, it is possible to realize various additional processes within an allowable range while maintaining a common processing system on the standard system of the operating system 12a.
[0024]
As a premise of executing such a program, the computer main body 12 includes a CPU 12e, a RAM 12f, a ROM 12g, an I / O 12h, and the like, and the CPU 12e that executes arithmetic processing uses the RAM 12f as a temporary work area or a setting storage area. While using it as a program area, the basic program written in the ROM 12g is appropriately executed to control external devices and internal devices connected via the I / O 12h.
[0025]
Here, the application 12i is executed on the operating system 12a as a basic program. The processing contents of the application 12i are various. The operation of the keyboard 15a and the mouse 15b as operation devices is monitored, and when the operation is performed, various external devices are appropriately controlled to execute corresponding arithmetic processing. Further, the processing result is displayed on the display 17a or output to the color printer 17b.
[0026]
In such a computer system, image data is acquired by a scanner 11a or the like as an image input device, and after performing predetermined image processing by an application 12i, the image data is displayed on a display 17a as an image output device, a color printer 17b or a projector 17c. It is possible.
[0027]
In the present embodiment, the image processing apparatus is realized as a computer system. However, such a computer system is not necessarily required, and any system that requires color adjustment processing according to the present invention for similar image data may be used. Just fine. For example, a system in which an image processing apparatus for performing the color adjustment processing according to the present invention is incorporated in a digital still camera and a color printer prints using the image data subjected to the color adjustment processing may be used.
[0028]
In addition, the present invention is naturally applicable to various devices that handle image data, such as a color facsimile device, a color copying device, and a projector.
[0029]
Processing Control Program The processing control program according to the present invention is generally distributed in a form readable by the computer 12 in a recording medium such as a floppy disk or a CD-ROM. The program is read by a media reader (CD-ROM drive 13c, floppy disk drive 13a, etc.) and installed on the hard disk 13b. Then, the CPU is configured to read a desired program from the hard disk 13b as appropriate and execute a desired process. The processing control program itself according to the present invention also constitutes a part of the present invention.
[0030]
Configuration of Image Processing Apparatus Here, returning to FIG. 1, details of each unit of the image processing apparatus 20 will be described.
[0031]
Note that the image input device 10 corresponds to the scanner 11a, the digital still camera 11b, and the video camera 11c. The image processing device 20 corresponds to a printer driver (PRT DRV) 12c.
[0032]
The color conversion unit 20a receives RGB gradation data (color image data) for each pixel from the image input device 10 (corresponding to the image input devices 11a to 11c), and receives CMYK (cyan, magenta, yellow, and black) floors. Convert to key data. Among the conversion results of the color conversion unit 20a, C (cyan) and M (magenta) are sent to the dark and light ink usage determining unit 20c as, for example, 100-gradation image data. Y (yellow) and K (black) are sent to the ink usage determining unit 20q.
[0033]
The density ink usage recording unit 20b records the gradation image data for each pixel and the usage of various inks in association with each other. The color printer 17b performs printing using ink corresponding to each color of CMYKcm. The dark and light ink usage recording unit 20b stores the amount (0 to 100) of the dark ink (C ′, M ′) and the light ink (c ′, m) corresponding to each gradation from 0 to 100 gradations of C and M. An LUT (Looking Up Table: reference table) indicating the quantity (0 to 100) of ') is recorded. For example, in the case of 100 gradations of C, it is recorded that the amount of the dark ink C ′ is 60 and the amount of the light ink c ′ is 40. The light ink c ′ displays light cyan (c), and the light ink m ′ displays light magenta (m).
[0034]
FIG. 3 shows an example in which the LUT recorded by the density ink usage recording unit 20b is expressed in a graph format. In FIG. 3, the gray scale is plotted on the horizontal axis and the ink quantity is plotted on the vertical axis. The coordinates are represented as (gradation, ink amount). The ink amount indicated by a straight line connecting (0, 0) and (100, 100) is called a linear ink amount.
[0035]
As shown in FIG. 3, the graph showing the amount of the light ink (c ′, m ′) passes through the origin. Then, the amount of light ink increases linearly (that is, the graph is linear) until the gradation reaches 60, and the ink amount reaches the maximum value 75 when the gradation is 60. The gradation from 0 to 60 is referred to as a light ink amount increasing region. In the light ink amount increasing region, the rate of increase in the amount of light ink (slope of the graph) is greater than the rate of increase of the linear ink amount (slope of the graph). Until the gradation reaches 75, the ink amount remains at the maximum value of 75. The gradation from 60 to 75 is called a light ink amount horizontal area. When the gradation exceeds 75, the amount of the light ink decreases linearly up to the maximum gradation 100. The gradation from 75 to 100 is called a light ink amount reduction region. The minimum value 40 of the light ink amount in the light ink amount reduction region is seen at the gradation 100.
[0036]
The graph showing the amount of the dark ink (C ′, M ′) indicates that the dark ink amount is 0 from 0 to 60. The dark ink amount continues to increase from the gradation of 60 to the maximum gradation of 100. Further, even if the dark ink amount takes the maximum value 60, the highest gradation 100 cannot be expressed only by the dark ink. In order to express the highest gradation 100, light ink must be used in an amount of 40 in addition to dark ink. In the graph indicating the amount of the dark ink (C ′, M ′), the gradient gradually increases from the gradation 60 to the vicinity thereof, and then increases with the gradient kept constant. Then, when the gradation reaches around 100, the inclination gradually decreases.
[0037]
FIG. 4 shows the sum of the dark ink amount and the light ink amount when the dark and light ink amounts shown in FIG. 3 are used. For gradations 0 to 60, the amount of dark ink = 0, so the amount of light ink is the sum of the amounts of ink as it is.
[0038]
Although the amount of dark ink increases from gradations 60 to 75, the gradient of the graph indicating the total amount of ink is approximately equal to the gradient of the graph indicating the amount of dark ink because the dark ink amount is in the horizontal region. .
[0039]
Although the amount of dark ink increases from gradations 75 to 100, the total amount of ink slightly increases because of the light ink amount reduction region, and the total amount of ink at the maximum gradation 100 is 100. For example, it is the maximum value of the ink amount that can be allowed in the medium (print medium).
[0040]
As described above, in almost all gradations, the sum of the ink amounts exceeds the linear ink amount.
[0041]
The reason why the amounts of the dark ink and the light ink are used to exceed the linear ink amount will be described with reference to FIG. FIG. 5 shows a state where 16 dots are covered with ink. When the density of the dark ink is twice the density of the light ink, as shown in FIG. 5A, the density obtained when all 16 dots are covered by the light ink, and as shown in FIG. This is equal to the density when 8 dots are covered with the dark ink. In FIG. 5B, when the landing positions of the dots are periodically shifted due to the vibration of the ink jet head or the like, the white portions are noticeable as unevenness or white streaks, causing printing unevenness. As described above, when a large amount of dark ink is used, a white portion is easily conspicuous. Therefore, if light ink is used, the total amount of ink is increased, the area covered by the ink is increased as much as possible, and white portions are reduced, so that printing unevenness hardly occurs. It should be noted that printing unevenness is unlikely to occur when only light ink is used, but when printing is performed at a high gradation (high density), the amount of ink exceeds a permissible ink amount for a medium (printing medium). Therefore, since it is not sufficient to use only light ink, dark ink is also used.
[0042]
The dark and light ink usage determining unit 20c receives the C and M gradation image data from the color conversion unit 20a, and, based on the recording contents of the dark and light ink consumption recording unit 20b, the dark and dark gradation corresponding to the C and M gradation image data. The amount of ink (C ′, M ′) and light ink (c ′, m ′) used is determined. For example, when receiving 100 gradations of C, the used amount of the dark ink C ′ is set to 60, and the used amount of the light ink c ′ is set to 40.
[0043]
The dot rate recording unit 20d records the ink amount and the dot generation rate corresponding thereto. This recorded content is also an LUT. The dots are divided into three types, large, medium, and small. The size of the dot is arbitrarily determined.
[0044]
FIG. 6 shows an example in which the LUT recorded by the dot rate recording unit 20d is represented in a graph format. As shown in FIG. 6, the dot generation rate of the small dots is proportional to the ink amount until the ink amount becomes 0 to 20, and becomes constant at 25% after the ink amount becomes 20. . The medium dot is 0 until the ink amount changes from 0 to 20. From 20 to 45, the dot generation rate continues to increase at a constant rate with the increase in ink amount, and after the ink amount becomes 45, the dot generation rate becomes constant at 20%. The large dot is 0 until the ink amount changes from 0 to 45. From 45 to 100, the dot generation rate continues to increase at a constant rate with the increase in the ink amount, and the dot generation rate = 55% (ink amount = 100).
[0045]
The light ink dot rate determination unit 20e receives the usage amount of the light ink (c ′, m ′) from the dark and light ink usage amount determination unit 20c, and determines the dot generation rate based on the recording content of the dot rate recording unit 20d. . For example, when the usage amount of the light ink (c ′, m ′) is 45, the incidence of large dots is 0%, the incidence of medium dots is 20%, and the incidence of small dots is 25%. It is determined. The result of determining the dot occurrence rate by the light ink dot rate determination unit 20e is as shown in FIG. Assuming that the amount of light ink used at gradation 16 in FIG. 3 is 20, the dot generation rate 20 is 25% for small dots, 0% for medium dots, and 0% for large dots from the graph of FIG. Similarly, if the amount of light ink used is 45 at the gradation 36 in FIG. 3, the dot occurrence rate 45 is 25% for small dots, 20% for medium dots, and 0% for large dots from the graph in FIG.
[0046]
The dark ink dot rate determining unit 20f receives the usage amount of the dark ink (C ′, M ′) from the dark and light ink usage amount determining unit 20c, and determines the dot generation rate based on the recording content of the dot rate recording unit 20d. . For example, when the used amount of the dark ink (C ′, M ′) is 45, the incidence of large dots is 0%, the incidence of medium dots is 20%, and the incidence of small dots is 25%. It is determined. The result of determining the dot generation rate by the light ink dot rate determination unit 20e is as shown in FIG.
[0047]
The ink usage amount recording unit 20p records an LUT indicating the amount of ink (0 to 100) corresponding to each gradation from 0 to 100 gradations of Y and K.
[0048]
The ink usage determining unit 20q receives the Y and K gradation image data from the color conversion unit 20a, and uses the ink corresponding to the Y and K gradation image data based on the recording content of the ink usage recording unit 20p. Determine the amount.
[0049]
The dot rate determination unit 20r receives the usage amounts of the Y and K inks from the ink usage amount determination unit 20q, and determines the dot generation rate based on the recording content of the dot rate recording unit 20d.
[0050]
The color printer 17b receives the large, medium, and small dot generation rates corresponding to each color of CMYKcm from the light ink dot ratio determination unit 20e, the dark ink dot ratio determination unit 20f, and the dot ratio determination unit 20r. The color printer 17b is an inkjet printer, and has an inkjet head corresponding to each color of CMYKcm. The voltage for driving the inkjet head is appropriately controlled to generate large, medium, and small dots for each color.
[0051]
Next, the operation of the embodiment of the present invention will be described.
[0052]
RGB gradation image data is provided from the image input device 10 to the image processing device 20. The color conversion unit 20a of the image processing device 20 converts the RGB gradation image data into CMYK gradation image data. The Y and K gradation image data are provided to the ink usage determining unit 20q, and the Y and K ink usage is determined. The dot rate determination unit 20r determines the Y and K dot rates from the Y and K ink usage amounts, and gives the Y and K dot rates to the color printer 17b.
[0053]
The gradation image data of C and M is provided to the dark and light ink usage determining unit 20c. The dark and light ink usage determining unit 20c determines the amount of the dark ink (C ′, M ′) and the light ink (c ′, m ′) based on the recording content of the dark and light ink usage recording unit 20b. Based on the amount of the dark ink (C ′, M ′), the dark ink dot rate determination unit 20f determines the dot rate of the dark ink (C ′, M ′) and gives it to the color printer 17b. Based on the amount of the light ink (c ′, m ′), the light ink dot rate determination unit 20e determines the dot rate of the light ink (c ′, m ′) and gives it to the color printer 17b.
[0054]
The color printer 17b drives an inkjet head corresponding to each color of CMYKcm, and generates large, medium, and small dots for each color.
[0055]
According to the embodiment of the present invention, since the sum of the ink amounts exceeds the linear ink amount in almost all gradations, it is possible to prevent uneven printing. This is for the following reason.
[0056]
When a large amount of dark ink is used, as described with reference to FIG. 5, the area of the portion covered by the ink is reduced, and printing unevenness is likely to occur. However, if light ink is used and the sum of the ink amounts is equal to or greater than the linear ink amount, the area of the portion covered by the ink increases, and printing unevenness can be suppressed.
[0057]
In addition, the amount of light ink in the light ink amount reduction region (see FIG. 3) exceeds 0 even at the minimum (40). For this reason, in the light ink amount reduction region, since light ink is always used, the ink amount increases, the area of the portion covered by the ink increases, and printing unevenness can be suppressed.
[0058]
Further, the dark ink amount is set to be lower than the density corresponding to the highest gradation 100 even at the highest gradation, and the ink other than the dark ink is used even at the highest gradation (not the highest gradation). In addition, the amount of ink increases, the area of the portion covered by the ink increases, and printing unevenness can be suppressed.
[0059]
Here, as the gradation increases, the rate of increase in the amount of light ink (the slope of the graph) gradually decreases to 0 (the amount of light ink takes the highest value), and thereafter, the amount of light ink decreases. It is also conceivable that the ratio (slope of the graph) gradually increases (a so-called curved graph).
[0060]
However, when the light ink amount horizontal area (see FIG. 3) is provided as in the present embodiment, the light ink amount becomes smaller than when the light ink amount takes the maximum value only in one gradation. The rate of decrease is slow, the amount of ink increases, the area of the portion covered by the ink increases, and printing unevenness can be suppressed.
[0061]
Further, since there is a light ink amount increasing region (see FIG. 3), the light ink amount increases more rapidly than the linear ink amount, and the area of the portion covered by the ink increases, so that printing unevenness can be suppressed.
[Brief description of the drawings]
FIG. 1 is a block diagram of an image processing system to which an image processing control method according to an embodiment of the present invention is applied.
FIG. 2 is a schematic block diagram illustrating a specific hardware configuration example of an image processing apparatus according to an embodiment of the present invention.
FIG. 3 is an example of an LUT recorded by a dark and light ink consumption recording unit 20b in a graph format.
FIG. 4 is a graph showing the sum of the dark ink amount and the light ink amount when the dark and light ink amounts shown in FIG. 3 are used.
FIG. 5 is a diagram showing a state in which 16 dots are covered with ink; a state in which all 16 dots are covered with light ink (FIG. 5A); and a state in which 8 dots are covered with dark ink (FIG. 5 ( b)) is shown.
FIG. 6 is an example of an LUT recorded by a dot rate recording unit 20d expressed in a graph format.
FIG. 7 is a diagram showing a result of determining a dot occurrence rate by a light ink dot rate determining unit 20e.
FIG. 8 is a diagram showing a result of determining a dot occurrence rate by a light ink dot rate determining unit 20e.
[Explanation of symbols]
Reference Signs List 10 Image input device 17b Color printer 20 Image processing device 20a Color conversion unit 20b Light and dark ink consumption recording unit 20c Light and dark ink consumption determination unit 20d Dot rate recording unit 20e Light ink dot ratio determination unit 20f Dark ink dot ratio determination unit 20p Ink Usage amount recording unit 20q Ink usage amount determination unit 20r Dot rate determination unit

Claims (9)

An image processing apparatus for determining the amount of ink used when performing printing using two or more types of inks having different densities for at least one hue,
The gradation image data for each pixel is recorded in association with the amount of use of various inks, and the recorded content is such that the sum of the amount of use of the ink is substantially equal to the total amount of gradation of the gradation image data. A density ink usage recording means that exceeds the linear ink amount in which the total usage amount is proportional to the gradation,
Receiving the gradation image data, based on the recording content of the gradation ink usage recording unit, determining a consumption amount of the ink corresponding to the gradation image data,
An image processing apparatus comprising: The image processing device according to claim 1,
The linear ink amount takes the maximum ink amount that can be used for a print medium at the highest gradation of the gradation image data.
Image processing device. The image processing device according to claim 1,
The recording content in the dark and light ink usage recording means includes a lightest ink amount decreasing area in which the lightest lightest ink amount of the ink decreases with an increase in the gradation of the gradation image data,
The minimum value of the lightest ink amount in the lightest ink amount reduction region exceeds 0,
Image processing device. The image processing device according to claim 1,
The density that can be represented only by the darkest ink of the highest density is less than the density corresponding to the highest gradation of the gradation image data.
Image processing device. The image processing device according to claim 1,
The recording content of the dark and light ink usage recording means is such that, as the gradation of the gradation image data increases, the lightest ink amount in which the amount of the lightest lightest ink among the inks takes a substantially constant maximum value. Including the area,
Image processing device. The image processing device according to claim 1,
The recording content of the dark and light ink usage recording means, the rate at which the amount of the lightest lightest ink among the inks increases, includes a lightest ink amount increasing area larger than the rate at which the linear ink amount increases.
Image processing device. An image processing method for determining the amount of ink used when performing printing using two or more types of inks having different densities for at least one hue,
The gradation image data for each pixel is recorded in association with the amount of use of various inks, and the recorded content is such that the sum of the amount of use of the ink is substantially equal to the total amount of gradation of the gradation image data. A density ink use amount recording step that exceeds the linear ink amount in which the sum of the use amount is proportional to the gradation;
Receiving the gradation image data, based on the recording content in the gradation ink usage recording step, determining a gradation ink consumption amount determining step of determining a consumption amount of the ink corresponding to the gradation image data;
An image processing method comprising: A program for causing a computer to execute an image processing process for determining the amount of ink used when printing using two or more types of inks having different densities for at least one hue,
The gradation image data for each pixel is recorded in association with the amount of use of various inks, and the recorded content is such that the sum of the amount of use of the ink is substantially equal to the total amount of gradation of the gradation image data. A density ink usage recording process that exceeds the linear ink volume in which the sum of the usage volumes is proportional to the gradation;
Receiving the gradation image data, based on the recording content in the gradation ink usage recording process, determining the amount of ink used corresponding to the gradation image data;
A program for causing a computer to execute. A computer-readable recording medium that stores the program according to claim 8.

Images