JP2014119845A - Print control device and print control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce effort and costs required for knowing the image quality in a print result in accordance with selection of a print condition.SOLUTION: A print control device comprises: a selection acceptance section for accepting selection of a print condition from among a plurality of print conditions; an unevenness information acquisition section for acquiring unevenness information preliminarily generated and indicating a feature of density unevenness in a print result by a printer under the selected print condition; a display control section for causing a prescribed display to display the image quality reproduced according to the acquired unevenness information; and a print control section for causing the printer to execute printing with respect to a print object image specified as a print object under the condition selected from among the plurality of print conditions. The plurality of print conditions include at least different print speeds.

Description

  The present invention relates to a print control apparatus and a print control method.

  In the printing result by the printer, density unevenness (image quality deterioration) due to characteristics specific to each printer body (for example, characteristics related to print head behavior, ink discharge nozzle arrangement accuracy, paper feed accuracy, etc.). A kind of noise). Correction techniques for suppressing the occurrence of such density unevenness are known (see Patent Documents 1 to 3).

JP 2012-14149 A JP 2000-103053 A JP 2010-220182 A

  However, even if correction for suppressing the occurrence of density unevenness is performed by a printer maker before shipping the product, or by a user when using the printer, it is difficult to reduce the density unevenness to zero. In such a situation, when a user prints a desired image with a printer, the user wants to know how much density unevenness occurs in the printing result. Conventionally, such density unevenness can be known by actually operating a printer, performing test printing of a sample image, and analyzing the print result of the sample image.

  The printer may have a plurality of printing modes (various printing modes such as high-speed printing and high-definition printing). Different printing modes have different printing speed and image quality (the degree of density unevenness appearing in the printing result). In addition, the degree to which the printing speed and the image quality are determined differs for each user. Therefore, the user can test print a sample image in each print mode using the printer, analyze each print result of the sample image corresponding to each print mode, and then print that best matches the printing speed and image quality required by the user. There was a need to select a mode. However, repeating such test printing has forced the user to spend a lot of time and money (ink fee, media fee, labor cost, etc.). In addition, the image quality required by the user for the print result varies depending on the environment planned when the print result is observed. However, it is very complicated or practically impossible for the user to evaluate the print result of the sample image under the planned environment. Therefore, it has been very difficult to obtain a print result with an image quality that satisfies the user in the planned environment.

  The present invention has been made to solve at least one of the above-described problems, and provides a technique capable of dramatically reducing a user's burden for knowing the image quality of a print result.

  According to one aspect of the present invention, the print control apparatus includes a selection receiving unit that receives a selection of a printing condition from a plurality of printing conditions, and density unevenness in a printing result by the printing apparatus under the selected printing condition. An unevenness information acquisition unit that acquires previously generated unevenness information indicating the characteristics of the image, a display control unit that displays an image quality reproduced according to the acquired unevenness information on a predetermined display, and a print target designated as a print target A printing control unit that causes the printing apparatus to execute printing according to a printing condition selected from the plurality of printing conditions for the image, and the plurality of printing conditions include at least different printing speeds. is there.

  According to this configuration, the user can know the image quality reproduced when printing is performed on the printing apparatus using the printing conditions only by arbitrarily selecting the printing conditions via the display. In other words, the user does not need to execute any trial printing as in the past. Since the user can easily know the image quality (degree of density unevenness) corresponding to the selected printing condition in this way, the user can easily select the optimum printing condition for printing the print target image (confirm the selection). Can).

In one aspect of the present invention, the plurality of printing conditions may include different print media.
According to this configuration, when the user selects a printing condition including a printing speed and a printing medium, the user can easily know the image quality (the degree of density unevenness) corresponding to the selected printing condition.

One aspect of the present invention is that the selection receiving unit is configured such that, in a situation where the printing speed and the printing medium are selected, the printing apparatus cannot cope with the printing conditions based on the selected printing speed and the printing medium. The printing apparatus may recommend outside the selection of other print media that can be printed at the selected printing speed.
According to this configuration, when the printing speed selected by the user and the printing conditions by the printing medium are not compatible with the printing apparatus, another printing medium that can be printed at the printing speed is recommended to the user. . Therefore, the user can easily find a print medium that realizes an acceptable image quality while keeping the desired printing speed.

One aspect of the present invention is that the selection receiving unit is capable of responding to a printing condition based on the selected printing speed and the printing medium in a situation where the printing speed and the printing medium are selected. When the instruction is received, the printing apparatus may present other print media that can be printed at the selected printing speed to the outside.
According to this configuration, the printing speed selected by the user and the printing conditions based on the printing media can be handled by the printing apparatus, and when a specific instruction is received from the user, printing is possible at that printing speed. Print media is presented to the user. Therefore, the user can easily find a print medium that realizes an acceptable image quality while maintaining a desired printing speed from among a larger number of options.

In one aspect of the present invention, the display control unit may display a composite image of an image reproduced in accordance with the unevenness information and the print target image on the display.
According to this configuration, on the display, the result of printing the print target image (print result including density unevenness) by the printing device according to the selected printing condition is displayed in a simulation in advance (before printing the print target image). The Therefore, the user can know the image quality corresponding to the printing conditions accurately and easily by viewing this display, and can select the optimum printing conditions (confirm the selection).

In one aspect of the present invention, the selection receiving unit can receive a selection of an observation distance, and the display control unit displays the image quality with the sharpness changed according to the selected observation distance. It may be allowed.
According to this configuration, the user can arbitrarily select the observation distance (a kind of the environment described above) planned when observing the print result, and the image quality with the sharpness changed according to the observation distance. You can know through the display. In other words, the user can perform image quality (density) corresponding to the selected printing condition and the observation distance without performing a very complicated action such as observing and evaluating the print result of the test print at a position separated by the observation distance. The degree of unevenness).

  As one aspect of the present invention, changing the sharpness according to the selected observation distance is to reduce the high-frequency component in the image representing the image quality as the observation distance is longer. It is good. When a person observes an observation object from a long distance, the sensitivity to high frequency components decreases. Therefore, the image quality equivalent to the image quality recognized when the user actually observes from the selected observation distance is displayed by changing the sharpness according to the observation distance as described above. Can be reproduced above.

  The technical idea according to the present invention is not realized only by the form of the print control apparatus, but may be embodied by another object (apparatus). Also, an invention of a method (printing control method) including a process corresponding to the characteristics of the printing control apparatus of any one of the above-described aspects, an invention of a printing control program for causing a predetermined hardware (computer) to execute the method, The invention of a computer-readable recording medium in which the program is recorded can also be grasped. The print control apparatus may be realized by a single apparatus or may be realized by a combination of a plurality of apparatuses. The print control apparatus may be realized by a single printing apparatus having a printing function and a display function.

It is a figure which shows a hardware configuration and a software configuration. It is a flowchart which shows a nonuniformity information generation process. It is a figure which illustrates a typical noise waveform. It is a figure which illustrates a typical noise waveform. It is a figure which shows a part of parameter optimization process notionally. It is a figure which illustrates a parameter table. 6 is a flowchart illustrating print control processing. It is a figure which illustrates an image quality confirmation screen. It is a figure which illustrates a contrast sensitivity curve and a contrast relative sensitivity curve.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1. FIG. 1 schematically shows a hardware configuration and a software configuration according to the present embodiment. In FIG. 1, a computer 10 as a personal computer (PC) and a printer 50 are shown. The computer 10 and / or the printer 50 correspond to a print control apparatus. The computer 10 and the printer 50 or the printer 50 also correspond to a printing apparatus. It can also be said that the computer 10 and the printer 50 constitute one printing system 1. In the computer 10, the CPU 11 controls the printer 50 by expanding the program data 21 stored in the hard disk drive (HDD) 20 or the like to the RAM 12 and performing calculations according to the program data 21 under the OS. The printer driver 13 is executed. The printer driver 13 is a print control for causing the CPU 11 to execute functions such as a print condition setting unit (selection receiving unit) 13a, an image data acquisition unit 13b, an unevenness information acquisition unit 13c, a display control unit 13d, and a print control unit 13e. It is a program. Each of these functions will be described later.

  A display 30 is connected to the computer 10, and a user interface (UI) screen necessary for each process is displayed on the display 30. In addition, the computer 10 appropriately includes an operation unit 40 realized by, for example, a keyboard, a mouse, a touch pad, a touch panel, and the like, and instructions necessary for each process are input by the user via the operation unit 40. A printer 50 is connected to the computer 10. As will be described later, in the computer 10, a print command is generated based on image data representing an image to be printed by the function of the printer driver 13, and the print command is transmitted to the printer 50.

  In the printer 50, the CPU 51 expands the program data 54 stored in the memory such as the ROM 53 into the RAM 52 and performs a calculation according to the program data 54 under the OS, thereby controlling the firmware FW for controlling the device itself. Is executed. The firmware FW can execute printing based on the print data by interpreting the print command transmitted from the computer 10 and extracting the print data and sending it to the ASIC 56. The firmware FW obtains image data representing an image to be printed from a memory card attached to an external connection connector (not shown), an external device (for example, the computer 10), etc., and prints based on the obtained image data. Data can also be generated. As described above, even when the print data is generated by the function of the firmware FW, the print data is sent to the ASIC 56.

  The ASIC 56 acquires print data, and generates a drive signal for driving the transport mechanism 57, the carriage motor 58, and the print head 62 based on the print data. The printer 50 includes a carriage 60, and the carriage 60 is loaded with ink cartridges 61 for each of a plurality of types of ink. For example, an ink cartridge 61 corresponding to various inks such as cyan (C), magenta (M), yellow (Y), and black (K) is mounted. Of course, the specific types and number of inks used by the printer 50 are not limited to those described above, and various inks such as light cyan, light magenta, orange, green, gray, light gray, white, metallic, etc. are used. Is possible. Further, the ink cartridge 61 may be installed at a predetermined position in the printer 50 without being mounted on the carriage 60. The carriage 60 includes a print head 62 that ejects (discharges) ink supplied from each ink cartridge 61 from a number of nozzles.

  The transport mechanism 57 includes a paper feed motor and a paper feed roller (not shown), and is driven and controlled by the ASIC 56 to transport the print medium along the transport direction (also referred to as a sub-scanning direction). By controlling the driving of the carriage motor 58 by the ASIC 56, the carriage 60 (and the print head 62) moves (main scanning) in a direction (main scanning direction) substantially orthogonal to the sub-scanning direction, and the ASIC 56 Along with the scanning, ink is ejected from each nozzle to the print head 62 at a predetermined timing. Thereby, ink droplets (dots) adhere to the print medium, and the image (print target image) indicated by the print command is reproduced on the print medium. The printer 50 further includes an operation panel 59. The operation panel 59 includes a display unit (for example, a liquid crystal panel), a touch panel formed in the display unit, various buttons and keys, and accepts input from the user and displays a necessary UI screen on the display unit. . The printer 50 stores a parameter table PT in a memory such as the ROM 53. The parameter table PT (or a part of the information in the parameter table PT) is an example of “unevenness information” generated in advance indicating characteristics of density unevenness in a printing result by the printing apparatus (printer 50). In addition to the serial printer type in which the print head moves in the main scanning direction as described above, the printer 50 may be a model having a line type print head in which a large number of nozzles are fixed side by side in the main scanning direction. It may be a page printer or the like.

2. Uneven Information Generation Process Next, the uneven information generation process will be described with reference to FIG. The unevenness information generation process refers to a process for generating the unevenness information. Here, the unevenness information generation processing is processing executed by the printer manufacturer before shipment of the printer 50, and the processing subject is the parameter table (PT) generation device 70. The PT generation device 70 includes a computer. The unevenness information generation process roughly includes a sample image printing colorimetry process (step S100), a parameter optimization process (step S200), and a parameter table storage process (step S300).

  In the sample image printing colorimetric process (step S100), the PT generation device 70 causes the printer 50 to print a predetermined sample image in accordance with the operation of the operator (step S100A). At this time, the PT generation device 70 causes the printer 50 to execute printing by specifying at least the print mode and the type of the print medium as print conditions. The printer 50 has a plurality of print modes. The difference in printing mode mainly means a difference in printing speed. Also, the difference in printing speed makes the image quality of the printing result different. That is, a printing mode with a relatively high printing speed has a relatively low image quality, and a printing mode with a relatively slow printing speed has a relatively high image quality. In this embodiment, as an example, the printer 50 has a plurality of print modes such as a print mode 1 (high speed and low image quality), a print mode 2 (medium speed and medium image quality), and a print mode 3 (low speed and high image quality). Various specific contents of the sample image are conceivable, but here, as an example of an image that can easily evaluate density unevenness in the print result, a solid image of a specific color (for example, black or gray) is used.

As a result of step S100A, the printer 50 prints the sample image on the print medium designated by the designated print mode.
Next, the PT generation device 70 performs color measurement on the printing result (printed sample image) obtained in step S100A using a predetermined color measurement device (for example, a scanner) in accordance with the operation of the operator. As a result, the PT generation device 70 acquires colorimetric data of the printed sample image (step S100B). The color measurement data is, for example, an RGB image having gradations of red (R), green (G), and blue (B) for each pixel.

In the parameter optimization process (step S200), the PT generation device 70 extracts a brightness image from the RGB image obtained from the color measurement (step S200A). Specifically, PT generator 70 calculates the L ^* a ^* b ^* image represented by L ^* a ^* b ^* color system by the color converting each pixel of the RGB image. The color conversion can be executed by referring to a profile that defines the conversion relationship between RGB and the L ^* a ^* b ^* color system specified by the International Commission on Illumination (CIE). Furthermore, the PT generation device 70 obtains a lightness image SLI in which each pixel is represented by lightness L ^* by extracting only the lightness L ^* channel of each pixel in the L ^* a ^* b ^* image.

Such a lightness image SLI is an image including inherent density unevenness generated when the printer 50 executes printing on the designated print medium in the designated print mode.
In addition, the PT generation device 70 sets one type of waveform for parameter setting from among a plurality of types of typical noise waveforms that can be an element of density unevenness in the printing result (step S200B).

3A, 3B, and 4A, 4B respectively show the typical noise waveforms that can be set as parameter setting targets in step S200B. Each graph defines the lightness L ^* on the vertical axis and the position x on the horizontal axis. FIG. 3A shows a sine wave as an example of the typical noise waveform. That is, the graph of FIG. 3A is a colorimetric measurement of a sample unevenness image PI whose density changes in a sine wave shape in one direction X along the one direction X (the sub scanning direction of the printer) as illustrated on the right side of the graph. The lightness L ^* obtained at each position x is shown. Similarly, the graph in FIG. 3B shows a triangular wave (substantially isosceles triangular waveform) as an example of the typical noise waveform, and the graph in FIG. 3C shows a sawtooth wave (substantially right angle) as an example of the typical noise waveform. 4A shows a rectangular wave as an example of the typical noise waveform, and the graph of FIG. 4B shows a spike wave (a streaky waveform) as an example of the typical noise waveform. Is shown.

Next, the PT generation device 70 sets various parameters for representing the variation of the color value Y using the noise waveform set in step S200B (step S200C). In the present embodiment, the fluctuation of the color value Y due to density unevenness is expressed by the following equation (1).
Y = df (ax + b) + c (1)

Y indicates the lightness L ^* , the function f (x) is a function representing the noise waveform (eg, sine wave) set in step S200B, and x is the pixel position. Of the parameters a, b, c, and d, a is the period, b is the phase, c is a constant term for adjusting the position in the vertical axis direction, and d is the amplitude.
In the present embodiment, parameters a, b, c, and d are optimized by repeatedly executing steps S200C to S200F. Therefore, the parameters a, b, c, and d set in step S200C immediately after step S200B may be any appropriate numerical value, and are not particularly limited. In this embodiment, in step S200C immediately after step S200B, initial values of parameters a, b, c, and d prepared in advance are set.

  Next, the PT generation device 70 shows the fluctuation of the color value Y defined by the noise waveform (function f (x)) set in step S200B and the parameters a, b, c, d set in step S200C. An image RI is generated (step S200D).

FIG. 5 is a diagram conceptually showing the processes of steps S200D to S200F. The row image RI is an image in which a plurality of pixels are arranged in one direction X, and each pixel has a color value Y (lightness L ^* ) corresponding to the pixel position x.
Next, the PT generation device 70 copies such row images RI and arranges a plurality of them in a direction orthogonal to the row direction (one direction X), whereby an uneven image NI having a spread in the vertical and horizontal directions (two directions orthogonal). Is generated (step S200E).

Next, the PT generation device 70 compares the brightness image SLI generated in step S200A with the unevenness image NI generated in step S200E, and evaluates the degree of approximation of both images (step S200F). If the degree of approximation is sufficiently high, a “Yes” determination is made, and the process proceeds to step S200G. On the other hand, if the degree of approximation is insufficient, a “No” determination is made, and the process returns to step S200C. For example, the PT generation device 70 obtains a difference in brightness L ^* between pixels whose positions match between both images, and calculates a root mean square (RMS) of such differences for all pixels. . Then, when RMS is equal to or less than a predetermined threshold value, it is determined that the degree of approximation is sufficiently high. If the calculated RMS is greater than the threshold value, the PT generation device 70 returns to step S200C and changes at least a part of the parameters a, b, c, and d from the previous set values and resets them. (Reset parameters a, b, c, d so that RMS is reduced). Note that at the time of executing step S200F, the PT generation device 70 matches the vertical and horizontal pixel numbers of the brightness image SLI and the unevenness image NI.

  In step S200G, the PT generation device 70 sets the parameters a, b, c, and d set at the time of determining “Yes” in step S200F to the parameters a, b, c for the noise waveform set in step S200B. , D. Accordingly, the parameters a, b, c, and d regarding the noise waveform set in step S200B are the density unevenness (lightness image SLI) that appears in the print result of the sample image output from the printer 50 under a certain print mode. (The parameter optimization succeeds). If the above approximation degree is insufficient even if the cycle of steps S200C to S200F is repeated a predetermined number of times, the PT generator 70 determines that the element of density unevenness corresponding to the noise waveform set in step S200B is the brightness image SLI. And parameters a, b, c, and d for the noise waveform are not determined (parameter optimization failure).

  The PT generation device 70 returns to step S200B after success or failure in parameter optimization for a certain noise waveform. Then, a type of waveform (for example, a triangular wave) to be parameter set is newly set out of the plurality of types of typical noise waveforms, and the processing in step S200C and subsequent steps is similarly executed. Note that the method for evaluating the degree of approximation between the brightness image SLI and the unevenness image NI in step S200F is not limited to the method described above, and various known evaluation methods can be employed.

  The PT generation device 70 repeats the above-described sample image printing colorimetry process (step S100) and parameter optimization process (step S200) at least for the combination of print modes and print media that can be supported by the printer 50. As a result, the parameters a, b, c, and d for the plurality of types (or some of the types) of noise waveforms are obtained for each of a plurality of printing conditions (printing mode and printing medium).

  In the parameter table storage process (step S300), the PT generation device 70 tabulates the parameters a, b, c, and d that have been successfully optimized in accordance with the printing conditions and the noise waveform, and parameters as illustrated in FIG. A table PT is generated. The parameter table PT is stored in the memory in the printer 50 before shipment. Thereby, the unevenness information generation process ends. When the PT generation device 70 succeeds in optimizing the parameters a, b, c, d for a plurality of types of noise waveforms under one printing condition, the parameters a, b for all the noise waveforms that have been optimized successfully. b, c, d may be tabulated, or only parameters a, b, c, d for typical noise waveforms (basically, noise waveforms with the highest degree of approximation) are tabulated. Also good. FIG. 6 illustrates a parameter table PT generated using the latter method for simplicity.

  However, in the present embodiment, it suffices if the printing system 1 (FIG. 1) can acquire the parameter table PT unique to the printer 50. Therefore, in addition to the parameter table PT being stored in the printer 50 before shipment as described above, for example, the parameter table PT is included in the program data 21 installed in the computer 10 via the Internet or various media. It may be distributed (see FIG. 1). Alternatively, the parameter table PT may be loaded into the computer 10 via the Internet or various media separately from the program data 21.

3. Print Control Process FIG. 7 is a flowchart showing the print control process according to this embodiment. Here, description will be made assuming that the CPU 11 executes the flowchart by the printer driver 13 (printing control program). When the user operates the operation unit 40, arbitrary application software is activated and an arbitrary print target image is designated. Then, the user operates the operation unit 40 to display a UI screen for setting printing conditions on the display 30. In such a state, the printer driver 13 first executes a printing condition setting process (step S400).

  In the printing condition setting process (step S400), the printing condition setting unit 13a accepts selection of a printing condition when the printer 50 prints an image to be printed according to a user input via the UI screen (step S400A). Specifically, various print conditions such as the print mode and the type of print medium, as well as the printing direction, the layout with respect to the paper surface, the necessity of double-sided printing, and the like are accepted according to user input.

  Next, the unevenness information acquisition unit 13c acquires “unevenness information” generated in advance indicating characteristics of density unevenness in the printing result by the printer 50 under the printing condition selected in step S400A (step S400B). Specifically, the unevenness information acquisition unit 13c selects the noise waveform and the parameter a, which match the print conditions (print mode and print medium) selected in step S400A from the parameter table PT stored in the printer 50. The printer 50 is requested to read out b, c, d, and the noise waveform and parameters a, b, c, d read out in response to the request are acquired. For example, if the print mode and print medium selected in step S400A are conditions of print mode 1 and medium 1 (see FIG. 6), the noise waveform and parameters a, b, c, and d that match the conditions are set. Obtained from the parameter table PT. Alternatively, the unevenness information acquisition unit 13c may read the information in the table as appropriate after inputting the entire parameter table PT from the printer 50. Further, as described above, the parameter table PT may be acquired from sources other than the printer 50.

Next, the display control unit 13d generates a nonuniformity image according to the nonuniformity information acquired in step S400B (step S400C). The unevenness image generation procedure here is the same as steps S200D and S200E (FIG. 2) described above. That is, the row indicating the variation in the color value Y (lightness L ^* ) defined by the type of noise waveform acquired in step S400B (for example, a triangular wave) and the parameters a, b, c, and d acquired in step S400B. An uneven image is generated by generating an image, copying the row image, and arranging a plurality of rows in a direction orthogonal to the direction of the row image. The uneven image generated in step S400C is expressed as uneven image ON. A plurality of noise waveform and parameter a, b, c, and d information sets that match the conditions of the currently selected print mode and print media are described in the parameter table PT (for example, a set of parameters related to a triangular wave and If a set of parameters relating to a sine wave is described.), A plurality of uneven images ON corresponding to the plurality of sets of information are generated.

Next, the display control unit 13d generates a composite image CI of all the uneven images INI (images reproduced according to the uneven information) generated in step S400C and the print target image (step S400D). In this case, first, the image data acquisition unit 13b acquires image data (input image data) representing the print target image. The input image data is acquired from a predetermined storage area such as a memory card attached to the HDD 20 or an external connection connector (not shown). The input image data is, for example, an RGB image. Then, the display control unit 13d extracts a brightness image (an image in which each pixel is represented by the brightness L ^* ) from the input image data. The lightness image extraction procedure is the same as in step S200A (FIG. 2) described above. The brightness image extracted from the input image data is represented as a brightness image TLI. Then, the display control unit 13d superimposes the brightness image TLI and all the unevenness images INI generated in step S400C and synthesizes them in units of pixels (linearly sums the brightness L ^* ). In the synthesis, it is assumed that the number of pixels in the vertical and horizontal directions of the brightness image TLI and the unevenness image INI are matched.

When there are a plurality of uneven images INI generated in step S400C, composition may be performed after weighting the uneven images ON. The method of weighting is not limited. For example, the weighting factor specified under the rule that the ratio is increased as the degree of approximation is higher (RMS is smaller) when the parameters a, b, c, d that are the generation sources of the uneven image INI are optimized. May be combined with the nonuniformity image INI, and then each nonuniformity image NI may be combined. In this case, it is assumed that the approximation degree (RMS) value when the parameters a, b, c, and d are optimized is also stored in the parameter table PT.
Next, the display control unit 13d displays the composite image CI generated in Step S400D on the display 30 (Step S400E).

  FIG. 8 illustrates an image quality confirmation screen 31 displayed on the display 30 as a kind of UI screen in step S400E. The image quality confirmation screen 31 includes a composite image CI. The composite image CI visually represents the image quality reproduced according to the acquired “unevenness information” unique to the printer 50. Further, the composite image CI indicates density unevenness (unevenness image INI) that will appear in the print result when the printer 50 performs printing under the printing conditions selected by the user at that time, and print target image It is shown superimposed on (lightness image TLI). The image quality confirmation screen 31 includes a pull-down menu 31a for selecting a print mode, a pull-down menu 31b for selecting a print medium, a print button 31d, a cancel button 31e, and the like.

  The user can select a print mode and a print medium arbitrarily from the pull-down menus 31a and 31b by operating the operation unit 40. The display control unit 13d receives a change in the selection of the print mode or the print medium in a state where the composite image CI corresponding to the currently selected print mode and the print medium is displayed on the display 30 (step S400E) ( Step S400A) generates a non-uniform image based on the non-uniformity information corresponding to the print mode and print medium for the selection after the change (Step S400B, S400C), and generates a composite image CI with the brightness image TLI (Step S400D). The latest synthesized image CI generated is displayed on the display 30 (step S400E). That is, in the print condition setting process (step S400), the composite image CI that matches the selection status is automatically displayed on the image quality confirmation screen 31 in conjunction with the user's print mode and print media selection status.

  The specific design in the image quality confirmation screen 31 is not limited to that illustrated in FIG. For example, a plurality of composite images CI corresponding to different printing conditions may be displayed in one screen, and a plurality of composite images CI corresponding to different printing conditions may be displayed by scrolling the screen. May be. Such a configuration for executing the printing condition setting process (step S400) can also be called, for example, an image quality display control device, a density unevenness display control device (display control method, display control program), or the like. Note that Steps S400A ′ and S400D ′ illustrated in FIG. 7 and the pull-down menu 31c illustrated in FIG. 8 will be described in a later-described modification.

  The user can operate (press down) the print button 31d by operating the operation unit 40. The operation on the print button 31d means a print start instruction for the print target image. When receiving the print start instruction (step S410), the print control unit 13e generates print data based on the input image data representing the print target image (step S420). More specifically, resolution conversion processing for causing the number of pixels of the input image data to correspond to the printing resolution of the printer 50, and the gradation of each color of the input image data (RGB values) in the ink color system used by the printer 50 Color conversion processing for converting to, halftone processing for converting the gradation of each pixel after color conversion processing into dot ejection / non-ejection information (halftone data) in each pixel, and transferring the halftone data to the printer 50 A known process such as a rasterizing process for generating print data rearranged in power order is executed. In addition, the print control unit 13e generates a print command including the print data, and transmits the print command to the printer 50 (step S430). The print command includes information for specifying the print condition that was selected when the print start instruction was received. As a result, the printer 50 executes printing based on the transmitted print command (printing the image to be printed under the designated printing conditions).

  As described above, according to the present embodiment, when the printing control apparatus receives selection of a printing condition from a plurality of printing conditions including at least different printing speeds (printing modes), the printing control apparatus performs the processing under the selected printing condition. The pre-generated unevenness information indicating the characteristics of unevenness in density in the printing result by the printer 50 is acquired, and the image quality reproduced according to the unevenness information is displayed on the display 30. That is, the image quality of the printing result by the printer 50 under the printing conditions is automatically displayed on the display 30 only by the user arbitrarily selecting the printing conditions. For this reason, the user can know exactly what image quality can be obtained by selecting which printing condition before starting to print the image to be printed with very little effort. It is possible to obtain a printing result that satisfies the image quality. Further, it is possible to solve the problem of wasting a lot of time and money by repeating the trial printing in order to know the optimum printing conditions for obtaining a desired printing result as in the prior art.

  In particular, in the present embodiment, the composite image CI of the unevenness image NI reproduced based on the type of noise waveform read from the parameter table PT and the parameters a, b, c, d and the brightness image TLI extracted from the print target image is displayed. 30. Therefore, the user can visually recognize the print target image that will be actually printed by the printer 50 under the printing condition selected at that time, before starting printing, and the printing condition selection work It is extremely useful for

4). Modifications The present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible. The contents combined with the above-described embodiments and modifications are also within the scope of disclosure of the present invention.

Modification 1:
The assumed distance (observation distance) between the printed matter and the user (user's eyes) observing the printed matter varies depending on the use and size of the printed matter. For example, the viewing distance is about several tens of centimeters (for example, 30 cm) in the case of a document or the like printed on a paper of about A4 size, while the viewing distance is several in the case of a huge poster posted outdoors. Distances such as meters or tens of meters are assumed. Moreover, even if the density unevenness is the same, if the observation distance is different, the user's evaluation for the density unevenness is different. In other words, even if there is density unevenness that can be recognized when the user observes from a short distance, the density unevenness may not be recognized when the user observes from a distance. Therefore, when displaying the image quality reproduced according to the unevenness information on the display 30, it is preferable to perform display according to the observation distance assumed by the user. Therefore, in the first modification, the print control apparatus changes the sharpness of the image quality according to the observation distance arbitrarily selected by the user when displaying the image quality reproduced according to the unevenness information on the display 30. To display.

  Specifically, the print condition setting unit (selection receiving unit) 13a receives not only the print condition for the print target image (step S400A) but also the observation distance assumed when observing the print result of the print target image. Is selected according to user input via the UI screen (step S400A ′, see FIG. 7). For example, the UI screen includes a pull-down menu 31c (see FIG. 8) for selecting an observation distance. The user can arbitrarily select the observation distance by operating the operation unit 40 from the observation distances listed in the pull-down menu 31c. Alternatively, the user may select the observation distance by directly inputting a numerical value indicating a desired observation distance in the UI screen.

  In addition, the display control unit 13d performs a blurring process according to the selected observation distance on the composite image CI generated in step S400D as a process of changing the sharpness of the image quality (step S400D ′, FIG. 7). When executing the blurring process, the display control unit 13d acquires information on the blurring amount according to the selected observation distance.

FIG. 9A illustrates contrast sensitivity curves for different observation distances. The contrast sensitivity curve is a curve that prescribes the relationship between the contrast sensitivity of human eyes and the spatial frequency, and how much the lightness and darkness changes (for example, black and white stripes) (how much spatial frequency) It shows whether there is sensitivity. The contrast sensitivity curve can be expressed by the following formula (2).

  In Expression (2), x is a spatial frequency (cycle / mm), and l is an observation distance (mm). FIG. 9A illustrates a plurality of contrast sensitivity curves corresponding to observation distances of 30 cm, 50 cm, 1 m, etc. As can be seen from FIG. 9A, the sensitivity of a person to a higher frequency component greatly decreases as the observation distance increases.

FIG. 9B illustrates a plurality of relative contrast sensitivity curves (contrast relative sensitivity curves) based on a certain observation distance. Here, as an example, the reference observation distance is 30 cm, and the contrast sensitivity curve corresponding to the arbitrary observation distance l is divided by the contrast sensitivity curve corresponding to the reference observation distance to obtain the contrast corresponding to the arbitrary observation distance l. Relative sensitivity curve. The contrast relative sensitivity curve can be expressed by the following equation (3).

  In Equation (3), x is a spatial frequency (cycle / mm), l is an observation distance (mm), f (x, 300) is a contrast sensitivity curve corresponding to a reference observation distance of 30 cm, f (x, l) is a contrast sensitivity curve corresponding to an arbitrary observation distance l. The display control unit 13d displays the contrast sensitivity curve f (x, 4000) corresponding to the observation distance (for example, the observation distance 4 m) selected in step S400A ′ and the contrast sensitivity curve f (x) corresponding to the reference observation distance 30 cm. , 300) is calculated based on the above equation (2), and the contrast relative sensitivity curve g (x, 4000) is calculated based on the above equation (3). The contrast relative sensitivity curve calculated in this way is a contrast relative sensitivity curve corresponding to the observation distance arbitrarily selected by the user, and corresponds to the blur amount.

  Next, the display control unit 13d generates an image expressed by a spatial frequency by performing a Fourier transform (FFT) on the composite image CI. Then, the amount of each frequency component is corrected (blurring process) by multiplying the spatial frequency image by the blur amount (contrast relative sensitivity curve corresponding to the observation distance arbitrarily selected by the user). At this time, the farther the observation distance selected by the user is, the more components are removed from the higher frequency side, and the sharpness of the image decreases. Then, the display control unit 13d performs an inverse Fourier transform (IFFT) on the spatial frequency image after the blurring process, thereby generating an image in which each pixel is expressed by a brightness component. Since the image represented by the lightness component is the composite image CI after the blurring process, in step S400E (see FIG. 7), the composite image CI after the blurring process is displayed on the display 30.

  As described above, according to the first modification, when the composite image CI is displayed on the display 30, the print control apparatus automatically multiplies the blur amount according to the observation distance arbitrarily selected by the user to obtain the sharpness. Display after changing. Therefore, the user can obtain an image quality equivalent to the image quality (the degree of density unevenness) that would be visually recognized when the print result of the print target image by the printer 50 is observed by being separated from the observation distance by the printer 50. You can know before printing. Therefore, the user's request to know the image quality of the print result observed at the actual observation distance can be surely met, and the user is freed from much trouble and cost.

  For the purpose of blurring the image, the contrast sensitivity curve can be set to the blur amount. However, in the first modification, the contrast relative sensitivity curve is set as the blur amount. This is due to the following reason. When a user observes a PC monitor or printed matter at hand, it is normal to see it at an approximately constant observation distance. In other words, when such an approximately constant observation distance visually recognizes density unevenness in an observation target. This is the standard observation distance. In other words, it is considered that the user hardly recognizes the “blur” generated at the reference observation distance as a blur, and recognizes the blur generated when viewing the observation target at a different observation distance as a blur. . Therefore, the contrast relative sensitivity curve calculated from the contrast sensitivity curve corresponding to the reference observation distance that the user is accustomed to based on experience and the contrast sensitivity curve corresponding to the observation distance arbitrarily selected by the user is used as the blur amount. By doing so, it is possible to present to the user via the display 30 an image quality that is almost as blurred as “blur” that the user actually recognizes at the arbitrary observation distance.

  The user may be able to select a plurality of observation distances in the image quality confirmation screen 31. In this case, for example, the display control unit 13d may display a plurality of composite images CI each subjected to the blurring process according to the selected plurality of observation distances in one screen, or scroll the screen. Thus, a plurality of such composite images CI may be displayed. In the above description, the reference observation distance is a fixed value (for example, 30 cm). However, the reference observation distance may be selected by the user. That is, the printing condition setting unit (selection receiving unit) 13a is assumed when observing the reference observation distance on which the user observes many observation targets on a daily basis and the print result of the current print target image. Each of the observation distance (the above-mentioned arbitrary observation distance) may be accepted according to a user input via the UI screen.

Modification 2:
In the above-described embodiment, the composite image CI of the unevenness image NI and the brightness image TLI is displayed on the display 30. However, such a composite image is not necessarily required. For example, in the flowchart of FIG. 7, step S400D may not be executed, and the display control unit 13d may cause the display 30 to display the uneven image INI in step S400E. Even when the uneven image INI is displayed alone, the degree of density unevenness and the pattern in the printing result by the printer 50 can be visually recognized when selecting the printing condition, which is meaningful to the user.

  Further, when displaying the uneven image INI alone, the display control unit 13d may execute the blurring process (step S400D ′) according to the observation distance for the uneven image INI. That is, when displaying the unevenness image INI on the display 30, the sharpness of the image quality may be changed according to the observation distance arbitrarily selected by the user. Further, even when the composite image CI of the unevenness image NI and the brightness image TLI is displayed on the display 30, the display control unit 13d performs the blurring process (step S400D ′) according to the observation distance to the unevenness image INI. It may be executed on the target. That is, the timing for executing step S400D ′ may be after step S400C and before step S400D. In this case, the unevenness image NI after the blurring process is combined with the brightness image TLI, and the combined image CI is displayed on the display 30.

Modification 3:
In addition, when the image quality reproduced according to the “unevenness information” is displayed on the display 30, it can be displayed in the form of characters (messages) in addition to displaying the unevenness image ON and the composite image CI. For example, when the unevenness information corresponding to the selected printing condition can be acquired (step S400B), the display control unit 13d displays the type of noise waveform, the intensity of unevenness in density, the frequency, and the like as characters based on the unevenness information. 30 may be displayed. The intensity and frequency of density unevenness can be determined according to each parameter described in the parameter table PT. Further, the image quality display by such characters and the image quality display by the non-uniform image ON or the composite image CI may be combined on the display 30.

Modification 4:
There are a plurality of print speeds (print modes) that the printer 50 can handle and types of print media that the printer 50 can handle. However, the printer 50 does not necessarily support all combinations of the plurality of print modes and the plurality of print media. In the example shown in FIG. 6, the printer 50 can use only the media 1 and 2 for printing in the printing mode 2, and can use only the media 1 for printing in the printing mode 3. In view of such circumstances, the printing condition setting unit 13a determines that the printer 50 is incapable of responding to the printing conditions according to the selected printing mode and printing medium in a situation where the printing mode and the printing medium are selected. 50 may recommend the user to select other print media that can be printed in the selected print mode.

  For example, when the print mode 2 is selected by the pull-down menu 31a and the medium 3 is selected by the pull-down menu 31b on the image quality confirmation screen 31, the print condition setting unit 13a performs such printing. The combination of mode 2 and medium 3 is determined to be a printing condition that the printer 50 cannot handle. Then, the selection of the print mode 2 is given priority, and the display control unit 13d is instructed to recommend the types of print media (media 1, 2) that can be used for printing in the print mode 2 in the printer 50. Upon receiving the instruction, the display control unit 13d recommends on the image quality confirmation screen 31 the types of print media (media 1, 2) that can be used for printing in the print mode 2 in the printer 50. For example, when the printing mode 2 is selected, a message or the like is notified that only the medium 1 or the medium 2 can be selected. According to this configuration, it is possible to accurately present media options capable of realizing printing at the printing speed to a user who desires to keep the printing speed (printing mode) once selected. In addition, the user can easily confirm the image quality of the print result when using the recommended print medium on the image quality confirmation screen 31 by selecting the recommended print medium.

Modification 5:
In addition, the printing condition setting unit 13a allows the printer 50 to cope with the printing conditions based on the selected printing mode and the printing medium in a situation where the printing mode and the printing medium are selected, and gives a specific instruction from the user. If accepted, the printer 50 may present other print media that can be printed in the selected print mode to the user.

  For example, when the print mode 2 is selected by the pull-down menu 31a and the medium 2 is selected by the pull-down menu 31b on the image quality confirmation screen 31, the print condition setting unit 13a performs such printing. The combination of mode 2 and medium 2 is determined to be a printing condition that can be handled by the printer 50. In this situation, when a specific instruction (other media presentation request) is received from the user, the printer 50 presents another type of print media (media 1) that can be used for printing in the printing mode 2 concerned. To the display control unit 13d. Upon receiving the instruction, the display control unit 13d selects the type of print medium (medium 1) that can be used for printing in the currently selected print mode 2 other than the currently selected print medium. Present above. Various specific modes of the presentation are conceivable. For example, in a situation where the printing mode 2 is selected, a message or the like is notified that the medium 1 can be selected in addition to the medium 2. According to such a configuration, it is possible to accurately present other media capable of performing printing at the printing speed to a user who desires to keep the printing speed (printing mode) once selected. In addition, the user can easily confirm the image quality of the print result when using the presented print medium on the image quality confirmation screen 31 by selecting the presented print medium.

Modification 6:
The PT generation device 70 may cause the printer 50 to print a sample image for each ink color for each designated printing condition in the sample image printing colorimetry process (step S100 in FIG. 2). For example, a sample image for each ink color used by the printer 50 is printed, such as a sample image by C ink, a sample image by M ink, a sample image by Y ink, a sample image by K ink, and so on. Then, the degree of density unevenness is evaluated for each print result of the sample image for each ink color. The method for evaluating density unevenness is not particularly limited. For example, the variation (standard deviation or the like) of the colorimetric data of the printing result for each sample image is calculated and comparatively evaluated. As a result, the ink color having the largest density unevenness (large variation) is specified. Then, the PT generation device 70 extracts the brightness image SLI from the colorimetric data regarding the print result of the sample image with the ink color specified in this way (step S200A). That is, even in one printer 50, the density unevenness occurrence state may differ for each ink color (print head or nozzle row corresponding to the ink color). Therefore, by extracting the lightness image SLI from the sample image of the ink color having the largest density unevenness as described above, the most severe density unevenness that will appear in the print result is displayed to the user through the screen. Can do. That is, the worst image quality state when printing conditions are selected and printed by the printer 50 can be presented to the user in advance.

Modification 7:
Although the case where the computer 10 executes the print control process has been described above as an example, the print control process may be performed in the printer 50. That is, when the CPU 51 of the printer 50 executes the firmware FW (print control program), the print condition setting unit 13a, the image data acquisition unit 13b, the unevenness information acquisition unit 13c, the display control unit 13d, the print control unit 13e, and the like described above. Each function may be realized in the printer 50 and the flowchart of FIG. 7 may be realized. In addition, the CPU 51 accepts an operation for setting printing conditions, selecting an observation distance, and a print start instruction for the print target image from the user via the operation panel 59. Further, the image quality (composite image) display may be performed on the display unit provided in the operation panel 59. Alternatively, the flowchart of FIG. 7 may be realized by sharing the printer driver 13 and the firmware FW.

DESCRIPTION OF SYMBOLS 10 ... Computer, 11 ... CPU, 12 ... RAM, 13 ... Printer driver, 13a ... Print condition setting part, 13b ... Image data acquisition part, 13c ... Uneven information acquisition part, 13d ... Display control part, 13e ... Print control part, 20 ... HDD, 21 ... program data, 30 ... display, 31 ... image quality confirmation screen, 31a, 31b, 31c ... pull-down menu, 40 ... operation unit, 50 ... printer, 51 ... CPU, 52 ... RAM, 53 ... ROM, 59 ... Operation panel, 61 ... Ink cartridge, 62 ... Print head, PT ... Parameter table, NI, ON ... Uneven image, SLI, TLI ... Lightness image

Claims (8)

A selection receiving unit that receives a selection of printing conditions from a plurality of printing conditions;
An unevenness information acquisition unit that acquires unevenness information generated in advance indicating characteristics of density unevenness in a printing result by the printing apparatus under the selected printing conditions;
A display control unit for displaying an image quality reproduced according to the acquired unevenness information on a predetermined display;
A printing control unit that causes the printing apparatus to perform printing according to a printing condition selected from the plurality of printing conditions for a printing target image designated as a printing target;
The printing control apparatus, wherein the plurality of printing conditions include at least different printing speeds.   The print control apparatus according to claim 1, wherein the plurality of print conditions include different print media.   In the situation where the printing speed and the printing medium are selected, the selection receiving unit selects the printing apparatus when the printing apparatus cannot cope with the printing conditions based on the selected printing speed and the printing medium. The print control apparatus according to claim 2, wherein selection of another print medium that can be printed at a printing speed is recommended to the outside.   The selection receiving unit is capable of responding to a printing condition based on the selected printing speed and the printing medium in a situation where the printing speed and the printing medium are selected. The print control apparatus according to claim 2, wherein the printing apparatus presents another print medium that can be printed at the selected printing speed to the outside.   The said display control part displays the synthetic | combination image of the image reproduced according to the said nonuniformity information, and the said printing object image on the said display, The Claim 1 characterized by the above-mentioned. Print control device. The selection accepting unit can accept selection of an observation distance,
The print control apparatus according to claim 1, wherein the display control unit displays the image quality with a sharpness changed according to the selected observation distance.   The printing control apparatus according to claim 6, wherein changing the sharpness according to the selected observation distance is to reduce a component on a high frequency side in an image representing the image quality as the observation distance is longer. . A selection receiving step for receiving a selection of printing conditions from a plurality of printing conditions;
An unevenness information acquisition step of acquiring unevenness information generated in advance indicating characteristics of density unevenness in a printing result by the printing device under the selected printing conditions;
A display control step for displaying the image quality reproduced according to the acquired unevenness information on a predetermined display;
A printing control step for causing the printing apparatus to execute printing according to a printing condition selected from the plurality of printing conditions for a printing target image designated as a printing target,
The printing control method, wherein the plurality of printing conditions include at least different printing speeds.