JP2005286625A - Image processing apparatus and method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus and a method thereof capable of suitably expressing gray scale images such as warm black tone and cold black tone by referencing a one-dimensional LUT in response to a user's instruction among a plurality of one-dimensional LUTs. <P>SOLUTION: The image processing apparatus stores the plurality of lookup tables 40 to 42 used for toning processing of the gray scale images and receives a user's toning instruction to a received gray scale image. The image processing apparatus selects one lookup table among the stored tables on the basis of the toning instruction and references the lookup table to apply toning to the gray scale image. Then the image processing apparatus outputs the gray scale image subjected to the toning to a recording apparatus for recording the resulting image to a recording medium. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus and method for performing toning processing of a grayscale image.

  Conventional color ink jet recording apparatus (for example, using three colors of cyan, magenta, yellow or four colors obtained by adding one color to black, and special color inks such as light cyan, light magenta, red, and green) In a printing apparatus that performs printing, when outputting a gray scale image (so-called monochrome image), each color is mixed to express a gray scale (hereinafter referred to as “composite gray”) or black ink. It is common to represent a gray scale with one color (hereinafter referred to as “monochromatic gray”) (see, for example, Patent Document 1).

  However, it has been pointed out that there are the following problems when outputting a grayscale image in composite gray or monochrome gray.

  First, in the case of composite gray, it is possible to design a reddish gray scale (so-called warm black tone) or a bluish gray scale (so-called cool black tone) by combining inks. However, in this case, depending on the gradation, the so-called “color transition” in which gray becomes reddish or bluish may become a problem.

  In general, the dark portion of the gray scale is expressed by only one black ink or mixed with other colors only to adjust the color tone using mainly black ink. On the other hand, in the gray scale highlight portion, when black ink is used, graininess is often sacrificed, so that a plurality of inks other than black are combined to express gray. Therefore, the cause of the color shift is that it is difficult in design to reproduce gray of the same hue in all gray scale gradations.

  In addition, in the case of composite gray, there is a drawback that the gray balance is likely to be lost due to variations in the ink ejection amount due to individual differences in the heads.

  On the other hand, in the case of monochromatic gray, since only one color is used, color shift is not a problem, but there is a limitation that a gray scale can be expressed only by the color of the black ink itself. Therefore, a new problem arises that the black ink itself must be toned in order to express a warm black tone or a cool black tone gray scale.

  Therefore, recently, taking advantage of composite gray and single color gray, it is basically single color gray, but a method using color ink for toning (hereinafter referred to as “monochromatic gray scale”) has been proposed. Has been.

  In other words, with regard to the granularity of the highlight portion, the ink droplet is made smaller to improve the granularity, or the granularity is sacrificed while maintaining the droplet size, so that the black ink is positively applied from the highlight portion. Toning is performed by using it.

  FIG. 2 is a diagram for explaining output processing of a gray scale image by a conventional method using a single-color clay scale. In FIG. 2, an arrow 21 indicates that a grayscale image is input, and an arrow 22 refers to the one-dimensional lookup table 20 to output an output grayscale image in which the input grayscale image is toned. It represents that. For example, when an 8-bit grayscale image per pixel is input, a one-dimensional LUT (look-up table) 20 having 256 indexes is referred to and corresponds to the pixel value of each pixel of the input grayscale image. An index value corresponding to each ink color prepared in advance corresponding to the index is output as a pixel value of the output grayscale image.

  FIG. 3 is a diagram for explaining an example of the one-dimensional LUT 20 in FIG. In FIG. 3, one column at the left end is an index value of 0 to 255 corresponding to the input value. Corresponding to each value of the index, the output value of each color ink of cyan, magenta, yellow, and black is stored in order from the next row to the right.

  According to the method described above, it is possible to output a toned monochrome grayscale image by referring to a one-dimensional LUT represented by a composite gray prepared in advance for an input grayscale image. It has become.

In the example shown in FIG. 3, an 8-bit grayscale image per pixel is assumed, but the same color adjustment is possible for a grayscale image having 8 or more bits. For example, even an RGB 8-bit color image is weighted with an appropriate ratio (for example, 0.295: 0.634: 0.071 if the input color image is an RGB signal representing the NTSC color space). By calculating the average, it is possible to have the precision below the decimal point. In such a case, the number of indexes of the one-dimensional LUT may be simply set to a size corresponding to the number of bits of the input image, and even the grayscale image of 8 bits or more is similarly toned by the above method. It is possible to output a single-color grayscale image.
JP 2000-238299 A

  However, the above-described method for toning a gray scale image using a one-dimensional LUT can be applied to an apparatus having one one-dimensional LUT. Therefore, although a plurality of gray scale patterns such as warm black tone and cold black tone can be considered, there is a limitation that the gray scale pattern that can be realized in the conventional apparatus is limited to only one pattern for one apparatus. It was. Further, since only one one-dimensional LUT is held in the apparatus, it is difficult for the user to finely adjust the color tone.

  In addition, the applicant of the present application has not found a publicly known example in which a grayscale image is input and color adjustment is performed using a plurality of one-dimensional LUTs to output a grayscale image.

  The present invention has been made in consideration of such circumstances, and refers to a one-dimensional LUT according to a user's instruction from a plurality of one-dimensional LUTs for gray scale images such as warm and cold tones. An object of the present invention is to provide an image processing apparatus and method capable of suitably performing expression.

In order to solve the above problems, the present invention provides an image processing apparatus for toning and outputting a grayscale image to a recording apparatus that records a grayscale image on a recording medium,
An input means for inputting a grayscale image;
Table holding means for holding a plurality of lookup tables used for the toning processing of the grayscale image;
Accepting means for accepting a user's toning instruction for the grayscale image;
Selection means for selecting one lookup table from the table holding means based on the toning instruction;
Toning means for toning the grayscale image input by the input means with reference to the one lookup table selected by the selection means;
Output means for outputting a grayscale image toned by the toning means.

Further, the present invention is an image processing apparatus for toning and outputting a grayscale image to a recording apparatus that records a grayscale image on a recording medium,
An input means for inputting a grayscale image;
Table holding means for holding a plurality of lookup tables used for the toning processing of the grayscale image;
A receiving unit that receives a user's toning instruction for the grayscale image; and a synthesis that combines a new lookup table using the plurality of lookup tables held in the table holding unit based on the toning instruction. Means,
Toning means for toning the grayscale image input by the input means with reference to a new look-up table synthesized by the synthesizing means;
Output means for outputting a grayscale image toned by the toning means.

Furthermore, the present invention is an image processing method for toning and outputting a grayscale image to a recording apparatus that records a grayscale image on a recording medium,
An input process for inputting a grayscale image;
An accepting step of accepting a user's toning instruction for the grayscale image;
A selection step of selecting one lookup table from table holding means for holding a plurality of lookup tables used for the toning processing of the grayscale image based on the toning instruction;
A toning step of toning the grayscale image with reference to the one lookup table selected by the selection step;
An output step of outputting the grayscale image toned by the toning step.

Furthermore, the present invention is an image processing method for toning and outputting a grayscale image for a recording apparatus that records a grayscale image on a recording medium,
An input process for inputting a grayscale image;
An accepting step of accepting a user's toning instruction for the grayscale image;
Based on the toning instruction, a new look-up table is synthesized using the plurality of look-up tables held in a table holding means for holding a plurality of look-up tables used for the toning processing of the grayscale image. A synthesis process to
A toning step for toning the grayscale image input by the input step with reference to the new look-up table synthesized by the synthesizing step;
An output step of outputting the grayscale image toned by the toning step.

  According to the present invention, it is possible to suitably express a gray scale image such as a warm tone or a cool tone by referring to a one-dimensional LUT according to a user instruction from a plurality of one-dimensional LUTs.

  Hereinafter, with reference to the drawings, details of a grayscale image recording system including an image processing apparatus for toning a grayscale image and a recording apparatus for recording the toned gracescale image according to an embodiment of the present invention will be described. To do.

<First Embodiment>
FIG. 1 is a block diagram showing a hardware configuration of a grayscale image recording system according to the first embodiment of the present invention. In the gray scale image recording system shown in FIG. 1, 10 is an image processing apparatus such as a personal computer, and 11 is a recording apparatus realized by a color ink jet printer or the like.

  Reference numeral 1 denotes a CPU that assumes image processing, 2 denotes a ROM that stores a program for starting the image processing apparatus 10, and 3 denotes a RAM that is used as a work area for various programs. Reference numeral 4 denotes an external storage device composed of a hard disk or the like, which stores a plurality of one-dimensional LUTs, image processing programs, image data to be processed, and the like in this embodiment.

  5 is an input device controller for controlling input devices such as a keyboard and a mouse, 9 is a display, 6 is a display controller for controlling the display 9, and 7 is between the image processing apparatus 10 and the recording apparatus 11. An interface for exchanging commands and various data is shown.

  FIG. 4 is a block diagram illustrating a detailed configuration of the image processing apparatus 10 that performs toning processing of a grayscale image. The configuration shown in FIG. 4 can be configured in software using an image processing program stored in the external storage device 4 in FIG. FIG. 8 is a flowchart for explaining the operation procedure of the image processing apparatus according to the first embodiment of the present invention.

  In FIG. 4, each of the one-dimensional LUTs 40, 41, and 42 is configured by a table that can express gray scales having different color tones. In this embodiment, standard (normal) gray, warm black tone gray, It is a one-dimensional LUT table for cool black tone gray.

  Reference numeral 43 denotes a gray scale tone setting unit, which displays (presents) a dialog as shown in FIG. 5 on the display 9 of the image processing apparatus 10 (step S11), and displays a gray scale having a desired tone for the user. To be selected. That is, FIG. 5 is a diagram showing an example of a dialog for setting a color tone for gray scale printing displayed on the display 9 of the image processing apparatus 10 according to the first embodiment of the present invention. As shown in FIG. 5, in this embodiment, radio buttons corresponding to each of a plurality of lookup tables held in the image processing apparatus 10 are presented to the user using a dialog, and one radio is transmitted from the user. By accepting the button setting (step S12), the lookup table corresponding to the set radio button is selected.

  Reference numeral 44 denotes a one-dimensional LUT selection unit, which selects a one-dimensional LUT corresponding to the color tone set by the gray scale color tone setting unit 43 from the one-dimensional LUTs 40 to 42 (step S13). A work memory unit 45 stores the one-dimensional LUT selected by the one-dimensional LUT selection unit 44. Then, referring to the selected one-dimensional LUT stored in the work memory unit 45, the toning process is performed on the input grayscale image in the same manner as the conventional process described above with reference to FIG. 2 (step S14). An output grayscale image is obtained by outputting data corresponding to each ink color prepared in advance corresponding to the index.

  Then, the toned single-color grayscale image (output grayscale image) obtained by the above-described processing in the image processing apparatus 10 is further subjected to halftoning processing and the like, and is output (transferred) to the recording apparatus 11 ( In step S15, recording is performed on a recording medium such as paper. In this embodiment, three LUTs are used as selectable one-dimensional LUTs, but the types and numbers are not limited to these.

<Second Embodiment>
Next, a grayscale image recording system according to the second embodiment of the present invention will be described. The hardware configuration of the grayscale image recording system according to this embodiment is the same as the block diagram shown in FIG. However, the image processing program stored in the external recording device 4 is different from that of the first embodiment.

  FIG. 6 is a block diagram illustrating a detailed configuration of an image processing apparatus that performs toning processing of a grayscale image in the recording apparatus system according to the second embodiment of the present invention. The configuration shown in FIG. 6 can be configured in software using an image processing program stored in the external storage device 4 in FIG. FIG. 9 is a flowchart for explaining an operation procedure of the image processing apparatus according to the second embodiment of the present invention.

  In FIG. 6, the one-dimensional LUTs 40, 41, and 42 are configured by tables that can express gray scales of different tones as in the first embodiment. In this embodiment, the standard ( Normal) One-dimensional LUT table for gray, warm black tone gray, and cool black tone gray.

  A gray scale color setting unit 61 displays (presents) a dialog as shown in FIG. 7 on the display 9 of the image processing apparatus 10 (step S21), and a gray scale having a desired color tone for the user. To be selected. That is, FIG. 7 shows an example of a dialog for setting the color tone for gray scale printing displayed on the display 9 of the image processing apparatus 10 according to the second embodiment of the present invention using the slide bar. FIG. That is, the user sets the composition ratio of the one-dimensional LUT to be synthesized using the slide bar on the displayed dialog (step S22).

  Reference numeral 62 denotes a one-dimensional LUT synthesis unit. Then, the one-dimensional LUT synthesis unit 62 generates a new one-dimensional LUT using the one-dimensional LUTs 40 to 42 based on the color tone set by the grayscale color tone setting unit 61 (step S23). A work memory unit 45 stores a new one-dimensional LUT synthesized by the one-dimensional LUT synthesis unit 17. Then, referring to the selected one-dimensional LUT stored in the work memory unit 45, the toning process is performed on the input grayscale image in the same manner as the conventional process described above with reference to FIG. 2 (step S24). An output grayscale image is obtained by outputting data corresponding to each ink color prepared in advance corresponding to the index.

  For example, the gray scale color tone setting unit 61 according to the present embodiment can set a range from a warm black tone to a cool black tone in multiple stages using a slide bar. As an example, the normal position is set to 0, and the user is allowed to designate an arbitrary position in 100 increments in the warm black tone direction and 100 increments in the cool black tone direction, and the gray scale color tone is performed. In other words, the one-dimensional LUT synthesis unit 62 selects two one-dimensional LUTs according to the setting values set by the grayscale tone setting unit 61, and synthesizes the two one-dimensional LUTs according to the position of the slide bar. Like that.

  For example, if the slide bar is at a position close to warm tone, the standard and warm tone one-dimensional LUTs 40 and 41 are selected, and the output values stored in the respective LUTs are weighted at a ratio of 7: 3. Are combined to create a new one-dimensional LUT.

  Then, the toned single-color grayscale image (output grayscale image) obtained by the above-described processing in the image processing apparatus 10 is subjected to a halftoning process or the like as in the first embodiment, and the recording apparatus 11. Is output (transferred) to (step S25), and recording is performed on a recording medium such as paper. In the present embodiment, two LUTs are used as one-dimensional LUTs that can be combined. However, the types and the numbers to be combined are not limited to these. For example, one LUT may be generated by combining three or more LUTs.

<Other embodiments>
As described in the first and second embodiments, the image processing apparatus according to the present invention can be used exclusively for an ink jet recording apparatus that outputs a gray scale image. Any other recording device such as a laser beam printer (LBP) can be recorded by performing gray scale toning processing as long as it is a recording device that performs gray scale printing using toner or the like. It is.

  As described above, the embodiment has been described in detail. However, the present invention can take an embodiment as a system, apparatus, method, program, storage medium, or the like, and specifically includes a plurality of devices. The present invention may be applied to a system that is configured, or may be applied to an apparatus that includes a single device.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowchart shown in the figure) that realizes the functions of the above-described embodiment is directly or remotely supplied to the system or apparatus, and the computer of the system or apparatus Is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, or the like.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program of the present invention itself or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on the instruction of the program is a part of the actual processing. Alternatively, the functions of the above-described embodiment can be realized by performing all of them and performing the processing.

  Furthermore, after the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a block diagram which shows the hardware constitutions of the gray scale image recording system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the output process of the gray scale image by the method by the conventional monochromatic clay scale. It is a figure for demonstrating an example of the one-dimensional LUT20 in FIG. It is a block diagram which shows the detailed structure of the image processing apparatus 10 which performs the toning process of a gray scale image. It is a figure which shows an example of the dialog for setting the color tone for the gray scale printing displayed on the display 9 of the image processing apparatus 10 which concerns on the 1st Embodiment of this invention. FIG. 6 is a block diagram illustrating a detailed configuration of an image processing apparatus that performs toning processing of a grayscale image in a recording apparatus system according to a second embodiment of the present invention. It is a figure which shows an example of the dialog for setting the color tone for the gray scale printing displayed on the display 9 of the image processing apparatus 10 which concerns on the 2nd Embodiment of this invention using a slide bar. 5 is a flowchart for explaining an operation procedure of the image processing apparatus according to the first embodiment of the present invention. It is a flowchart for demonstrating the operation | movement procedure of the image processing apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

1 CPU
2 ROM
3 RAM
4 External storage device 5 Input device controller 6 Display controller 7 Interface 8 Bus 9 Display 10 Image processing device 11 Recording device 40, 41, 42 One-dimensional LUT
43, 61 Gray scale tone setting unit 44 One-dimensional LUT selection unit 45, 62 Work memory unit

Claims (13)

An image processing apparatus for toning and outputting a grayscale image to a recording apparatus that records a grayscale image on a recording medium,
An input means for inputting a grayscale image;
Table holding means for holding a plurality of lookup tables used for the toning processing of the grayscale image;
Accepting means for accepting a user's toning instruction for the grayscale image;
Selection means for selecting one lookup table from the table holding means based on the toning instruction;
Toning means for toning the grayscale image input by the input means with reference to the one lookup table selected by the selection means;
An image processing apparatus comprising: output means for outputting a grayscale image toned by the toning means. The selection means selects a standard lookup table from a plurality of lookup tables held in the holding means;
2. The image according to claim 1, wherein the toning unit adjusts the gray scale image input by the input unit to a standard gray scale image with reference to the standard lookup table. Processing equipment. The selecting means selects a warm-black tone look-up table from a plurality of look-up tables held in the holding means;
The toning means tones the gray scale image input by the input means to a warm black tone gray scale image with reference to the warm black tone look-up table. The image processing apparatus described. The selecting means selects a cool black tone look-up table from a plurality of look-up tables held in the holding means;
2. The toning means tones the gray scale image input by the input means to a cool black tone gray scale image with reference to the cool black tone look-up table. The image processing apparatus described. A presentation unit for presenting a user with a GUI screen having radio buttons corresponding to each of the plurality of lookup tables held in the holding unit;
The receiving unit receives a toning instruction using a lookup table corresponding to one radio button on the GUI screen designated by the user as a toning instruction for the grayscale image. The image processing apparatus according to 1. Based on the toning instruction, further comprising a synthesizing unit that synthesizes a new lookup table using a plurality of lookup tables held in the table holding unit;
The gray scale image input by the input unit with reference to either the one lookup table selected by the selection unit or the new lookup table synthesized by the synthesis unit by the toning unit The image processing apparatus according to claim 1, wherein the color is adjusted. An image processing apparatus for toning and outputting a grayscale image to a recording apparatus that records a grayscale image on a recording medium,
An input means for inputting a grayscale image;
Table holding means for holding a plurality of lookup tables used for the toning processing of the grayscale image;
Accepting means for accepting a user's toning instruction for the grayscale image;
A synthesizing unit that synthesizes a new lookup table using the plurality of lookup tables held in the table holding unit based on the toning instruction;
Toning means for toning the grayscale image input by the input means with reference to a new look-up table synthesized by the synthesizing means;
An image processing apparatus comprising: output means for outputting a grayscale image toned by the toning means. A setting unit that sets a use ratio of two lookup tables among the plurality of lookup tables held in the holding unit;
The accepting unit synthesizes the two look-up tables at the usage ratio set by the setting unit to generate a new look-up table, and outputs a toning instruction using the new look-up table to the gray scale Accept as image toning instructions,
The image processing apparatus according to claim 6 or 7, wherein the synthesizing unit generates a new look-up table by combining the two look-up tables by performing weighting according to the use ratio. . Further comprising a presentation means for presenting a user with a GUI screen having a slide bar corresponding to the usage rate,
9. The reception unit receives a toning instruction using a look-up table synthesized based on a use ratio corresponding to a position of a slide bar on the GUI screen set by the user. An image processing apparatus according to 1. An image processing method for toning and outputting a grayscale image for a recording apparatus that records a grayscale image on a recording medium,
An input process for inputting a grayscale image;
An accepting step of accepting a user's toning instruction for the grayscale image;
A selection step of selecting one lookup table from table holding means for holding a plurality of lookup tables used for the toning processing of the grayscale image based on the toning instruction;
A toning step of toning the grayscale image with reference to the one lookup table selected by the selection step;
And an output step of outputting the grayscale image toned by the toning step. An image processing method for toning and outputting a grayscale image for a recording apparatus that records a grayscale image on a recording medium,
An input process for inputting a grayscale image;
An accepting step of accepting a user's toning instruction for the grayscale image;
Based on the toning instruction, a new look-up table is synthesized using the plurality of look-up tables held in a table holding means for holding a plurality of look-up tables used for the toning processing of the grayscale image. A synthesis process to
A toning step for toning the grayscale image input by the input step with reference to the new look-up table synthesized by the synthesizing step;
And an output step of outputting the grayscale image toned by the toning step.   The program for making a computer perform the image processing method of Claim 10 or 11.   A computer-readable recording medium storing the program according to claim 12.

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