JP2001309195A - Image processing method and image processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing unit that can reproduce an original image from color input image information of the original image in a preferable way with less calculation amount and to decrease occurrence of color level deformation even at a high saturation part so as to preferably reproduce the color. SOLUTION: The image processing unit is provided with an input arithmetic means 131 that obtains an input neutral color contrast amount and an input deviation contrast amount from color input image information, a neutral color contrast amount arithmetic means 132 that obtains an output neutral color contrast amount from the received neutral control contrast amount on the basis of the neutral color contrast amount conversion information, a deviation contrast amount arithmetic means 134 that obtains an output deviation contrast amount from the input deviation contrast amount according to Expressions below, and an output arithmetic means 136 that obtains color output image information from the output neutral color contrast amount and the output deviation contrast amount. ΔR'=frr(ΔR)+frg(ΔG)+frb(ΔB), ΔG'=fgr(ΔR)+fgg(ΔG)+fgb(ΔB), and ΔB'=fbr(ΔR)+fgb(ΔG)+fbb(ΔB), where ΔR, ΔG, ΔB are the received deviation contrast amount, ΔR', ΔG', ΔB' are the output deviation contrast amount, fij() is conversion function and ij is r, g, b}.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method and an image processing apparatus.

[0002]

2. Description of the Related Art Conventionally, in order to obtain R, G, B color output image information for reproducing the original image from the R, G, B color input image information of the original image, R, G, B of the original image has to be obtained. Is converted to chromaticity coordinates from the color input image information of
Conversion to R, G, B color output image information to reproduce the original image has been performed.

In such a case, a technique for controlling colors such as preferable color reproduction and color reproduction close to the original image is extremely important in color image processing. However, in this conventional technique, since the conversion process is performed twice, there is a problem that an unnaturally reproduced image is generated. For example, unnatural coloring occurs due to an error in the conversion process at some places in the gradation of the neutral original image. Another problem is that the amount of calculation for reproducing the original image is large.

[0004] Such spectral characteristics of the image input device,
R, G, B for the purpose of photometric correction for improving color turbidity caused by the mismatch of the spectral characteristics of the original color materials, and for improving color reproduction due to differences in the spectral characteristics of the output field enhancement medium.
There is known a method of performing a 3 × 3 matrix operation on the image information.

In the method described in Japanese Patent Application Laid-Open No. 9-214794, a neutral color shading amount, R,
The G / B deviation shading amount is obtained, the output neutral color shading amount is obtained based on the neutral color shading amount shading amount conversion information, and a matrix operation is performed on the R, G, B deviation shading amount to output deviation. A method is described in which a shade amount is obtained, R, G, and B color output image information is obtained from the output neutral color shade amount and the output deviation shade amount, and preferable color reproduction is performed with a small calculation amount.

[0006]

However, in the vicinity of the boundary of the color gamut, especially in the high-saturation area, if the color conversion processing is performed, the color may stick to (concentrate on) the boundary of the color gamut. It has been found that there is a problem that the color is crushed (color crush) and the hue is shifted due to the inability to reproduce data beyond the color reproduction portion. In particular, it has been found that color crushing appears remarkably when the color enhancement processing for lifting up again is strongly applied.

SUMMARY OF THE INVENTION It is an object of the present invention to solve these problems, to realize an image processing method and an image processing apparatus capable of reducing the occurrence of color collapse even in a high chroma portion and achieving preferable color reproduction.

[0008]

The above objects of the present invention can be achieved by all matters specifying the invention described in the following claims.

(1) The first aspect of the present invention provides an image processing system in which R,
An image processing method for obtaining R, G, B color output image information from G, B color input image information, wherein the input neutral color shading amount, R, G, B
G and B input deviation shading amounts are obtained, and based on the neutral color shading amount conversion information, an output neutral color shading amount is obtained from the obtained input neutral shading amount. , G,
The R, G, and B output deviation shades are determined from the B input deviation shades, and the R, G, and B colors are determined from the determined output neutral shades and the determined R, G, and B output deviation shades. An image processing method for obtaining output image information. ΔR ′ = frr (ΔR) + frg (ΔG) + frb (ΔB) ΔG ′ = fgr (ΔR) + fgg (ΔG) + fgb (ΔB) ΔB ′ = fbr (ΔR) + fbg (ΔG) + fbb (ΔB) Here, the input deviation The gray level is ΔR, ΔG, ΔB, the output deviation gray level is ΔR ′, ΔG ′, ΔB ′, and the conversion function is fij ().
And let ij be {r, g, b}.

[0010] The invention according to claim 3 is a method for producing an R, G, B original image.
An image processing apparatus for obtaining R, G, B color output image information from color input image information of R, G, B, and an input neutral color shading amount, R, G, B from R, G, B color input image information. An input calculating means for obtaining an input deviation shading amount of the neutral color shading amount based on the neutral color shading amount conversion information, and obtaining an output neutral color shading amount from the input neutral shading amount obtained by the input calculating means. R, G, R
A deviation density calculating means for calculating the output deviation density of R, G, B from the input deviation density of B; an output neutral color density calculated by the neutral color density calculating means; and the deviation density calculating means. From the R, G, and B output deviation shading amounts obtained by
An output processing means for obtaining B color output image information. ΔR ′ = frr (ΔR) + frg (ΔG) + frb (ΔB) ΔG ′ = fgr (ΔR) + fgg (ΔG) + fgb (ΔB) ΔB ′ = fbr (ΔR) + fbg (ΔG) + fbb (ΔB) Here, the input deviation The gray level is ΔR, ΔG, ΔB, the output deviation gray level is ΔR ′, ΔG ′, ΔB ′, and the conversion function is fij ().
And let ij be {r, g, b}.

According to the present invention, color conversion and matrix operation are performed on the color components by dividing them into neutral density (input neutral color density) and color components (R, G, B input deviation density). After that, in the image processing to be added to the neutral density, each element of the matrix operation is not a simple constant but a function of a color component or a lookup table (hereinafter abbreviated as LUT).

For this reason, it is possible to remove color turbidity from the color components by emphasizing only the colors by the matrix operation using the functions of the color components. Accordingly, R, G, B color output image information capable of preferably reproducing the original image is obtained from the R, G, B color input image information of the original image with a small amount of calculation while reducing the occurrence of color collapse even in a high chroma portion. be able to.

(2) The invention according to claim 2 is characterized in that the deviation density conversion formula is independent for each combination of signs of the input deviation density of R, G, B. 1
It is an image processing method described.

According to a fourth aspect of the present invention, the deviation gray scale conversion formula is independent for each combination of the signs of the R, G, and B input deviation gray scales. An image processing device.

According to the present invention, the deviation gray level determined "independently" for each positive / negative combination of the input deviation gray levels of R, G, and B (for each color of R, G, B, Y, M, and C). Based on the conversion formula, the output deviation density is obtained from the input deviation density, so that when adjusting a certain color, it does not affect other colors including the component of that color, and the color turbidity is not affected. The occurrence can be suppressed, and the color can be controlled independently.

[Terms and Other Descriptions] In the specification of the present application, for the sake of simplicity, red (red) is R, green (green) is G, blue (blue) is B, and yellow (yellow) is Y. , Magenta is called M, and cyan is called C. Similarly, a yellow dye is called a Y dye, a magenta dye is called an M dye, and a cyan dye is called a C dye. Similarly, a yellow image mainly composed of a Y pigment is a Y image, a magenta image composed mainly of an M pigment is an M image, a cyan image mainly composed of a C pigment is a C image, and a yellow pigment / magenta pigment / An achromatic neutral image mixed with cyan dye is an N image,
An R image is a red image in which yellow and magenta dyes are mixed, a B image is a blue image in which magenta and cyan dyes are mixed, and a G image is a green image in which cyan and yellow dyes are mixed. ,.

In the specification of the present application, "input neutral color density" means the neutral color density of color input image information. Further, “R, G, B input deviation shading amount” is
This is the amount of deviation of the color input image information of the R, G, and B primary colors from the input neutral color intensity.

"Output neutral color shading amount" refers to the neutral color shading amount of color output image information. Also, "R, G, B
Is the amount of deviation from the output neutral color intensity of the color output image information of each of the R, G, and B primary colors.

The "image information" is generally called an image signal, and is information representing an image by a signal. The image information includes digital image information representing an image by a digital signal and analog image information representing an image by an analog signal.

The "deviation density conversion information" is generally referred to as color reproduction information, and is information for obtaining the output deviation density from the input deviation density. The "deviation density conversion information" is preferably matrix information for performing matrix conversion, but is not limited thereto, and may be, for example, LUT data. This matrix is preferably a 3 × 3 matrix.

The "neutral color shading amount conversion information" is generally called neutral color reproduction information, and is information for obtaining an output neutral color shading amount from an input neutral color shading amount. In the specification of the present application, the following terms are used for the following meanings.

An "original image" is an image that is the basis of the image processing of the present invention, and is displayed not only on a film such as a color film, a color print, and a printed matter that can be read photoelectrically, but also on a monitor. Signal and an electronic image such as a color digital image or a color analog signal image obtained by shooting.

"Neutral" refers to an achromatic color or a color having substantially zero saturation. The “color chart” is a standard sample for displaying colors, and usually has a plurality of color chart images recorded thereon. The “color patch image” is an image recorded on the color patch so as to be visually recognized.

The "second color patch" is a reproduction of a color patch reproduced based on information obtained by reading the color patch. The “second color patch image” is an image recorded on the second color patch so as to be visible.

The "shading amount" is an amount indicating shading. Examples of the shading amount include density, luminance, transmittance, and reflectance. Further, in the present invention, the shading amount includes a deviation shading amount such as an input deviation shading amount and an output deviation shading amount, and a neutral color shading amount such as an input neutral color shading amount and an output neutral shading amount.

"Storage medium" refers to a medium for storing information such as programs and data. As a storage medium, a magnetic recording medium such as a photo mini disk, a floppy (registered trademark) disk or a magnetic tape,
A recording medium such as an optical recording medium such as a ROM, a magneto-optical recording medium such as an MO disk, or a battery-backed R
Non-volatile storage media such as an AM chip, an IC card, and a ROM chip, and volatile storage media such as a RAM chip that is not backed up by a battery. Further, the storage medium may be an external storage medium or an internal storage medium. As a storage medium, a rewritable storage medium is better than a non-rewritable storage medium.
This is preferable because the setting can be easily changed.

"Hard copy" means an image of a permanent recording type as compared with a soft copy which is a transient image such as an image displayed on a monitor. A hardcopy that records an image such as a photograph is called "pictorial hardcopy".

In the present invention, it is preferable to obtain deviation density conversion information and neutral color density conversion information using a color chart image formed of the same pigment as the hard copy, since the image is preferably reproduced in color. ,preferable. In the present invention, it is preferable to obtain deviation density conversion information and neutral color density conversion information using a color chart image formed of the same pigment as the hard copy, since the image is preferably reproduced in color.

Further, in order to obtain deviation density conversion information and neutral color density conversion information, a color chart image or a second color chart image is photoelectrically read to obtain color input image information. It is preferable to use an image reading device that measures the amount of reflected light in a specific wavelength range, or an image reading device that measures the amount of reflected light in a specific wavelength range by selecting a light source.

The image reading device is a device for reading an image by light, and is a device for reading B,
Examples include a color image scanner having a linear image sensor for each of G and R and sub-scanning a color image, a color image scanner equipped with a two-dimensional image sensor, and a digital camera. Further, the image reading device may be integrated with the image processing device or the image forming device.

The image forming apparatus is not limited to a sublimation-type thermal transfer printer, a fusion-type thermal transfer printer, an electrophotographic printer, an ink jet printer, a printing apparatus, a CRT printer processor, and the like, but also an apparatus for creating a hard copy by itself. A combination of a sublimation type thermal transfer type color negative printer that creates a color negative from an input signal and a printer processor that creates a hard copy from the created color negative, and a CRT printer that prints an image on photographic paper using a CRT from an input signal A digital film recorder that prints an image on a color negative film using a negative writer that has a CRT or a laser optical system from input signals, a film processor that develops a printed color negative film, and a combination with an automatic processor that develops paper Present It may be composed of a plurality of devices, such as a combination of a printer processor for creating a hard copy from a color negative film which has been processed.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, specific examples of the present invention will be described as embodiments, but the present invention is not limited thereto. Further, although the embodiments have assertive expressions, preferred embodiments of the present invention are cited,
It does not limit the technical scope of the present invention or the meaning of the terms.

First Embodiment: [1. FIG. 1 is a block diagram showing an outline of a processing block of this embodiment, FIG. 3 is a schematic diagram showing an entire configuration of an image reproduction system of this embodiment, and FIG. It is a schematic diagram which shows a schematic structure.

First, the overall configuration will be described with reference to FIGS. FIG. 3 shows an image reproduction in which the original image 11 which is a color image of the present embodiment is read with reflected light, image processing is performed from the read color input image information to obtain color output image information, and a pictorial real hard copy is created. Shows the system.

This image reproduction system includes an image reading device 12 for reading a color image with reflected light, an image processing device 13 for performing image processing on color input image information obtained by reading to obtain color output image information. And an image forming apparatus 14 for creating a pictorial hard copy from the color output image information.

The image reading device 12 reads the original image 11 with the reflected light, and obtains color input image information indicating the reflectance of each of the R, G, and B primary colors of each pixel of the color image. The image reading device 12 has a CCD linear image sensor fixed to a color reflection original and having 5000 pixels for each of R, G, and B.
These CCD linear image sensors have R, G, and B filters on the incident light side, respectively.

Further, the image reading device 12 uses these CCs
The main scanning is performed by the D linear image sensor. The image reading device 12 has an optical unit having these CCD linear image sensors, a line light source, and a diffusion box for diffusing light from the line light source. Then, the image reading device 12
Is a color image scanner that performs sub-scanning by moving the optical unit in a direction perpendicular to the arrangement direction of the CCDs.

Thus, the light emitted from the linear light source becomes diffused light through the diffusion box, illuminates the color reflective original, and the reflected light from the illuminated color reflective original is R, G,
After passing through the B filter and entering the R, G, and B CCD linear image sensors, photometry of a color reflection original can be performed to determine the reflectance of each pixel. The spectral transmission characteristics of the R, G, B filters of the image reading device are R, G, B
It is preferable that the characteristic is hardly transmitted outside the respective wavelength regions.

The color input image information (Ir) read by the image reading device 12 has a reflectance of 0% and a reflectance of 10%.
This is converted from the reflectance Rt (%) by the following equation, where 0% is set to 255. Ir = Rt × (255/100) Then, the storage medium reading device 19 attached to the image processing device 13 reads out the deviation density from the conversion information storage medium 17 that stores the deviation density conversion information and the neutral color density conversion information. The amount conversion information and the neutral color shading amount conversion information are read.

As the conversion information storage medium 17, a photo mini disk shown in FIG. 3 is used. Of course, the conversion information storage medium 17 is not limited to this, and may be another external storage medium such as a floppy disk, or an internal storage medium such as a memory such as a ROM.

The image processing device 13 uses the read deviation shading amount conversion information and the neutral color shading amount conversion information to convert R, G, B from the color input image information obtained by the image reading device 12.
Color output image information of each primary color is obtained. Then, the image processing device 13 outputs the obtained color output image information to the image forming device 14.

The image forming apparatus 14, for example, heats and transfers to a dedicated hard copy sheet using sublimable dyes of three primary colors of Y, M, and C based on the color output image information, and performs pictorial real hard copy 15 Based on a sublimation type thermal transfer printer or a color output image information,
An ink jet printer (for example, MJC-700V2C Seiko Epson Corporation) for forming a pictorial hard copy 15 by forming an image on a dedicated hard copy sheet using ink of the four primary colors of M, C, and K (black ink) by an ink jet method. And a CRT printer (a printer that forms a hard copy by performing development processing after exposure) that exposes color photographic paper, which is a color photographic photosensitive material, based on color output image information can be used.

FIG. 4 shows the neutral color shading amount conversion information and deviation shading amount conversion information used for obtaining color output image information from color input image information in the above-described image reproduction system. A conversion information creation system for storing color density conversion information and deviation density conversion information in a conversion information storage medium 17 is shown.

The neutral color shading amount conversion information is conversion information for obtaining the output neutral color shading amount from the input neutral color shading amount obtained from the color input image information. Is conversion information for obtaining the output deviation gray level from the input deviation gray level obtained from the color input image information. The conversion information creation system includes a calculation image reading device 22 of the same model as the image reading device 12 of the image reproduction system, a calculation image forming device 24 of the same model as the image forming device 14 of the image reproduction system, Image reading device 28 for reading input image information for obtaining quantity conversion information
And the same model as the image processing device 13 of the image reproduction system, and stores the deviation density conversion information and the neutral color density conversion information obtained by the calculation image processing device 23 in the conversion information storage medium 17.
And a calculation image processing device 23 to which a storage medium writing device 29 for storing the information is stored.

First, a color chart 26 is created. The color chart 26 according to the present embodiment includes a Y image, an M image,
It has a C image, an N image, an R image, a G image, and a B image. Each Y image, M image, C image, N image, R image,
The G image and the B image have a certain area so that input image information can be measured by the image reading device. A Y image, an M image, and a C image having the same spectral coloring characteristics as the original image 11 read by the image reading device.
Color chart 2 having image, N image, R image, G image, and B image
6 is preferable because the image is best reproduced.

The color chart 26 may be created by, for example, an output device for creating the original image 11. Further, a color chart 26 having the same spectral color developing characteristics as the original image 11 read by the image reading apparatus.
In the case where it is difficult to prepare an image, a step printing tablet is used to expose R, G, B, neutral colors, Y, M, and C on color photographic paper, which is a silver halide color negative photographic photosensitive material, and then developed. It is preferable that a color print having a Y image, an M image, a C image, an N image, an R image, a G image, and a B image obtained by processing is used as the color chart 26. This is because color prints obtained from color photographic paper usually have less side absorption components than other media.

Then, the image reading device 28 measures the R, G, B input image information of the color chart 26. The image reading device 28 reads the color chart 26 and the second color chart 25 with reflected light,
It measures color input image information.

Further, the image reading device 22 for calculation uses the reflected light to cause the Y, M, C, N,
The R image, the B image, and the G image are read, and color input image information on the reflectance of each of the R, G, and B primary colors of each image is obtained.

The color input image information (Ir) read by the image reading device 12 has a reflectance of 0% and a reflectance of 10%.
This is converted from the reflectance Rt (%) by the following equation, where 0% is set to 255. Ir = Rt × (255/100) Then, the calculation image processing device 23 uses the color input image information itself transmitted from the calculation image reading device 22 as color output image information. That is, color output image information is obtained without performing any image processing on the color input image information.

Then, the calculation image forming apparatus 24 creates the second color chart 25 from the color output image information sent from the calculation image processing apparatus 23. Then, by comparing the color input image information obtained from the color chart 26 with the color input image information obtained from the second color chart 25, more preferably, the second color chart 25
Also obtains input image information of R, G, B by the image reading device 28, and then [3. Creation of deviation density conversion information] and [4. Creation of Neutral Color Shading Amount Conversion Information], the neutral color shading amount conversion information is obtained.

Then, the deviation density conversion information and the neutral color density conversion information obtained by the storage medium writing device 29 attached to the calculation image processing device 23 are stored in the conversion information storage medium 17.

In this embodiment, since the conversion information creation system and the image reproduction system are separate devices and are of the same model, the same image reproduction system as that of the image reproduction system is used at a factory or a sales agency. Using the reproduction system as a conversion information creating system, the deviation density conversion information and the neutral color density conversion information are precisely obtained in advance, and the conversion information storage medium 1 is obtained.
7, the conversion information storage medium 17 is supplied to an image reproduction system such as an end user separately from the image reproduction system, and an image is formed by the image reproduction system supplied with the conversion information storage medium 17. It has been described.

However, the image reproduction system itself may be used as a conversion information creation system at a factory or a sales agent to obtain the deviation density conversion information and the neutral color density conversion information.

Further, the deviation density conversion information and the neutral color density conversion information, which are precisely obtained in advance using the image reproduction system or the conversion information creation system of the same model as the image reproduction system, are stored in a ROM or the like. The conversion information storage medium is provided for the image reproduction system, and the image reproduction system provided with the conversion information storage medium storing the deviation density conversion information and the neutral color density conversion information is supplied to an end user or the like. Is also good.

Further, these deviation density conversion information and neutral color density conversion information are communicated through a network such as the Internet or a general telephone line to an image reproduction system of an end user in Japan or abroad from domestic or overseas. , May be supplied.

Further, a storage medium storing a program for creating neutral color shading amount conversion information and a program for creating deviation shading amount conversion information is supplied to an image reproducing system, and each end user can use the storage medium. May be set in the image reproduction system, these programs may be developed from the storage medium, and the end user may obtain the deviation density conversion information and the neutral color density conversion information by the image reproduction system.

Further, through a network such as the Internet, a general telephone line, or the like, information such as a program for creating these deviation density conversion information and a program for creating neutral color density conversion information is communicated. The supply may be from a domestic or foreign country to a domestic or foreign end-user image reproduction system.

It is preferable that the neutral color shading amount conversion information and the deviation shading amount conversion information are obtained for each type of color input image information. That is, it is preferable to obtain the reading characteristics of the image reading apparatus and the types of primary color pigments constituting the original image. Further, the neutral color shading amount conversion information and the deviation shading amount conversion information are:
It is preferable to obtain the color output image information for each type.
That is, it is preferable to obtain the value for each type of hard copy determined by the output characteristics of the image forming apparatus and the type of hard copy material such as a hard copy dye and hard copy recording paper.

Further, when the original is limited to silver halide color photographic prints, the conversion method is fixed depending on the reading characteristics of the image reading apparatus without the spectral coloring characteristics being largely different depending on the silver halide color photographic photosensitive material for printing. Even so, the color reproduction is not greatly disrupted. Therefore, in order to simplify the description, in the following method of creating neutral color shading amount conversion information and deviation shading amount conversion information, a case where the original image is a silver halide color photographic print will be described.

[2. Creation of Pictorial Hard Copy of Image Reproduction System] Hereinafter, creation of a pictorial hard copy of the present image reproduction system will be described in detail.

Here, FIG. 1 is a block diagram showing an outline of processing blocks of the image processing apparatus according to the present embodiment.
A description will be given with reference to FIG. 2 which is a flowchart showing a procedure for creating a pictorial hard copy.

First, the storage medium reading device 19 of the image processing device 13 converts the color output image information from the color input image information from the conversion information storage medium 17 for storing the deviation density conversion information and the neutral color density conversion information. The deviation density conversion information and the neutral color density conversion information to be obtained are read out. Here, the read deviation density conversion information is stored in the neutral color density conversion information storage unit 133. Further, the read neutral color shading amount conversion information is stored in the deviation shading amount conversion information storage means 135. Note that the neutral color shading amount conversion information storage means 133 and the deviation shading amount conversion information storage means 135 are formed in a predetermined area of a memory of the image processing apparatus 13.

Then, the image reading device 12 reads the original image 11, and R, G, B of each pixel (xy: x is the position of each pixel in the X direction, y is the position of each pixel in the Y direction) of the original image 11. Input image information (IRxy, IGx
y, IBxy: x is the position of each pixel in the X direction, and y is the position of each pixel in the Y direction (S1 in FIG. 2).

IRxy, IGxy, and IBxy indicate the position of the read original image in the X direction x, and y indicates the input image information of R, G, and B of the pixel whose position in the Y direction is y. Needless to say, color input image information (IRxy, IGxy, IB) related to the reflectance of R, G, B
xy) indicates that the photometry has been adjusted.
When the reflectance of both G and B is 100%, the IR
xy = IGxy = IBxy = 255.

Next, the original 1 obtained by the image reading device 12
The color input image information (IRxy, IGxy, IBxy) of each pixel (xy) of R, G, and B of the image processing device 33
Input through the data interface (Fig. 2S
2).

Here, gradation conversion for obtaining a desired gradation for output is performed (S3 in FIG. 2). Here, when the color input image information for the color n before the gradation conversion is Ii, the color input image information for the color n after the gradation conversion is Ii ′, and the signal value is 256 levels (0 to 255), The gradation conversion can be expressed by the following equation. Ii '=-log (Ii / 255) .times..alpha.i + .beta.i Then, for Ii' in the achromatic portion of the original image, αi and .beta.i are set so as to satisfy Ir '= Ig' = Ib '. The above-described gradation conversion is desirable. As a characteristic of the output device, it is desirable that an output image that outputs an output image value of Ir ′ = Ig ′ = Ib ′ be achromatic.

Next, the input operation means 1 of the image processing device 13
Reference numeral 31 denotes each of the color input image information from the color input image information (IRxy, IGxy, IBxy) relating to the reflectance of R, G, B of each pixel (xy) of the color input image information obtained by the image reading device 12. A neutral color shading amount of the pixel (xy) (hereinafter sometimes referred to as an input neutral color shading amount INxy) is obtained by the following equation (1) (S4 in FIG. 2).

Equation (1): INxy = αR × IRxy + αG × IGxy + αB × I
Bxy where αR, αG, and αB are coefficients determined by the color input image information, and can be determined by a known method.

The input operation means 1 of the image processing device 13
Reference numeral 31 denotes an input deviation density (ΔRxy, ΔGx), which is a density of a deviation from the neutral color density of each of R, G, B primary colors.
y, ΔBxy) is obtained by the following equation (2) (FIG. 2S
4).

Equation (2): ΔRxy = IRxy−INxy ΔGxy = IGxy−INxy ΔBxy = IBxy−INxy If the general expression is obtained without xy of the pixel, the input deviation density (ΔR, ΔG, ΔB) is It looks like this:

Equation (2) ': ΔR = IR-IN ΔG = IG-IN ΔB = IB-IN These may be calculated by matrix.

Next, the neutral color shading amount calculating means 132 of the image processing apparatus 13 stores the neutral color shading amount conversion information storing means 133.
The input neutral color intensity (INxy) is converted to the output neutral color intensity (PNBxy, PNGxy, PNRxy) of each pixel (xy) based on the neutral color intensity conversion information stored in the pixel data.
Is converted by a neutral color shading amount conversion function represented by the following equation (3).

Equation (3): PNRxy = αNR × INxy PNGxy = αNG × INxy PNBxy = αNB × INxy Needless to say, the image forming apparatus 14 is set properly by the setting method provided in the image forming apparatus. You get a hard copy while you are.

Next, based on the deviation density conversion information stored in the deviation density conversion information storage means 135, the deviation density calculation means 134 of the image processing apparatus 13 calculates the input deviation density (ΔRxy, ΔGxy, ΔGxy, ΔBxy), the output deviation shading amount (ΔR'xy, ΔG'xy,
ΔB′xy) is converted by a deviation density conversion function represented by the following equation (4) (S5 in FIG. 2).

Equation (4): ΔR′xy = frr (ΔRxy) + frg (ΔGxy) + f
rb (ΔBxy) ΔG′xy = fgr (ΔRxy) + fgg (ΔGxy) + f
gb (ΔBxy) ΔB′xy = fbr (ΔRxy) + fbg (ΔGxy) + f
bb (ΔBxy) Note that, when a general formula is used without the pixel xy, the output deviation shading amounts (ΔR ′, ΔG ′, ΔB ′) are as follows.

Equation (4) ′: ΔR ′ = frr (ΔR) + frg (ΔG) + frb (ΔB) ΔG ′ = fgr (ΔR) + fgg (ΔG) + fgb (ΔB) ΔB ′ = fbr (ΔR) + fbg (ΔG) + Fbb (ΔB) Here, the input deviation density is ΔR, ΔG, ΔB, the output deviation density is ΔR ′, ΔG ′, ΔB ′, and the conversion function is fij ().
And ij is {r, g, b}.

In such a conversion, each element of the matrix operation is not a simple constant but a function of a color component or an LUT.
It is composed of For this reason, by emphasizing only the color by the matrix operation using the function of the color component, it is possible to remove the turbidity from the color component.

Accordingly, the R, G, and B colors that can preferably reproduce the original image from the R, G, and B color input image information of the original image while reducing the occurrence of color collapse even in a high chroma portion with a small amount of calculation.
B color output image information can be obtained.

Note that the deviation shading amount conversion information is R, G, B
Is desirably determined for each positive / negative combination of the input deviation shading amount, and the following six cases are classified. ΔR ≧ 0, ΔG ≦ 0, ΔB ≦ 0 (when the color is R) ΔR ≦ 0, ΔG ≧ 0, ΔB ≦ 0 (when the color is G) ΔR ≦ 0, ΔG ≦ 0, ΔB ≧ 0 (when the color is B) ΔR ≦ 0, ΔG ≧ 0, ΔB ≧ 0 (when the color is C) ΔR ≧ 0, ΔG ≦ 0, ΔB ≧ 0 (when the color is M) When ΔR ≧ 0, ΔG ≧ 0, and ΔB ≦ 0 (when the color is Y) Thus, for each positive / negative combination of the R, G, B input deviation shading amounts (R, G, B, Y, M , C for each color), the output deviation shading amount is obtained from the input deviation shading amount based on the deviation shading amount conversion formula defined “independently” to adjust a certain color. Without affecting other colors, and suppressing the occurrence of color turbidity and independently controlling the colors.

Hereinafter, the effects of each of the above-mentioned items will be described. If the color input image information obtained by reading the original image by the image reading device 12 is used as the color output image information as it is, the R of the hard copy created by the image forming device
When the saturation of the color is reproduced low, the saturation of the R color is increased to make it vivid. On the other hand, if the color input image information obtained by reading the original image by the image reading device 12 is used as the color output image information as it is, the saturation of the R color of the hard copy created by the image forming device is reproduced at a high level. , Lowers the saturation of R color and reduces vividness.

If the color input image information obtained by reading the original image by the image reading device 12 is used as it is as the color output image information, if the saturation of the G color of the hard copy created by the image forming device is reproduced low, Increases color saturation and makes it vivid. Conversely, if the color input image information obtained by reading the original image by the image reading device 12 is used as it is as the color output image information, the saturation of the G color of the hard copy created by the image forming device is reproduced at a high level. , Lowers the saturation of G color and reduces vividness.

If the color input image information obtained by reading the original image by the image reading device 12 is used as the color output image information as it is, when the saturation of the B color of the hard copy created by the image forming device is reproduced low, Increases color saturation and makes it vivid. Conversely, if the color input image information obtained by reading the original image by the image reading device 12 is directly used as the color output image information, the saturation of the B color of the hard copy created by the image forming device is reproduced at a high level. , Lowers the saturation of B color and reduces vividness.

If the color input image information obtained by reading the original image by the image reading device 12 is used as it is as the color output image information, if the color saturation of the C color of the hard copy created by the image forming device is reproduced high, Decreases color saturation and reduces vividness. Conversely, if the color input image information obtained by reading the original image by the image reading device 12 is used as it is as the color output image information, the color saturation of the C color of the hard copy created by the image forming device is reproduced low. , Increase the saturation of C color and make it vivid.

If the color input image information obtained by reading the original image by the image reading device 12 is used as the color output image information as it is, if the saturation of the M color of the hard copy created by the image forming device is reproduced at a high level, M Decreases color saturation and reduces vividness. Conversely, if the color input image information obtained by reading the original image by the image reading device 12 is used as the color output image information as it is, the saturation of the M color of the hard copy created by the image forming device is reproduced low. , Increase the saturation of M color and make it vivid.

If the color input image information obtained by reading the original image by the image reading device 12 is used as the color output image information as it is, when the saturation of the Y color of the hard copy created by the image forming device is reproduced at a high level, Y Decreases color saturation and reduces vividness. Conversely, if the color input image information obtained by reading the original image by the image reading device 12 is used as the color output image information as it is, the saturation of the y-color of the hard copy created by the image forming device is reproduced low. , Increase the saturation of the y color and make it vivid.

Then, the output calculation means 136 of the image processing device 13 outputs the output neutral color shading amount (PN) of each pixel (xy).
From Rxy, PNGxy, PNBxy) and the output deviation shading amount (ΔR′xy, ΔG′xy, ΔB′xy), a color output image (PRxy, PGxy, PB) of each pixel (xy) is obtained.
xy) is obtained by the following equation (5) (S6 in FIG. 2).

Equation (5): PRxy = ΔR′xy + PNRxy PGxy = ΔG′xy + PNGxy PBxy = ΔB′xy + PNBxy Next, the image processing device 13 obtains the color output image (PRxy, PGxy, PBxy) of each obtained pixel (xy). ), The image is converted into the format of the image forming apparatus 14, color output image information is obtained, and sent to the image forming apparatus 14 (FIG. 2).
S7).

Then, the image forming apparatus 14 forms a pictorial hard copy 15 based on the input color output image information (S8 in FIG. 2). [3. Preparation of Deviation Shading Amount Conversion Information] The following is a color print obtained by exposing and developing a color photographic paper as a silver halide color negative photographic material,
A method for obtaining deviation density conversion information will be described in detail by taking, as an example, an image reproduction system that creates a hard copy with an RT printer and a development processing device.

FIG. 5 is a flow chart for creating deviation density conversion information. First, in FIG. 5S21, for example, a color chart 26 having an image with 15 levels of brightness (15 levels of density) as shown in FIG. 6 is created using color photographic paper (negative / positive type).

First, the relationship between the exposure amounts of R, G, and B such that the N image becomes achromatic is obtained. Then, the photographic paper is exposed to the light at a log E of 0. 0 so that the N images become achromatic.
Exposure is performed by increasing the exposure amount in increments of 05, and development processing is performed.
N images (Ni: i = 1) of step brightness (15 levels of density)
15), a B image (Bi: i = 1 to 15) with 15 levels of brightness (15 levels of density), and a G image (Gi: i = 1 to 15) with 15 levels of brightness (15 levels of density) ) And an R image (Ri: i = 1 to 15) of 15 levels of brightness (15 levels of density)
15), a Y image (Yi: i = 1 to 15) with 15 levels of brightness (15 levels of density), and an M image (Mi: i = 1 to 15) with 15 levels of brightness (15 levels of density) C image (Ci: i = 1 to 15) with 15 levels of brightness (15 levels of density)
Is created.

Here, the Y image is obtained only by exposure of the B primary color, the M image is obtained only by exposure of the G primary color, and the C image is obtained only by exposure of the R primary color. The exposure amounts of the Y image, M image, and C image at each lightness stage (density stage) are equal to the exposure amounts of the R, G, and B primary colors of the N image.
Therefore, for each brightness level (density level), the dye amounts of the Y, M, and C images are equal to the dye amounts of the Y, M, and C dyes of the N image.

The R image is obtained only by exposing the G primary color and the B primary color, the G image is obtained only by exposing the R primary color and the B primary color, and the B image is exposed by the R primary color and the G primary color. Obtained only by exposure. The exposure amounts of the R, G, and B primary colors of the R image, B image, and G image at each lightness level (density level) are the same as those of the N image except for the unexposed primary colors.
It is equal to the exposure amount of each of the primary colors G and B. Therefore, for each lightness step (density step), the Y dye of the R, G, and B images,
The dye amount of each color of the M dye and the C dye is equal to the dye amount of each color of the Y dye, the M dye, and the C dye of the N image except for the complementary color dye.

Accordingly, the Y, R, G, and N images at the corresponding lightness level (density level) have the same amount of Y dye, and the M, R, and B images at the corresponding lightness level (density level). The dye amount of the M dye in the image and the N image is equal, and the C dye in the C image, the G image, the B image, and the N image at the corresponding lightness level (density level) is equal.

Each of the fifteen levels of density is indicated by a mantissa i, and the mantissa i of the stage having the minimum exposure is set to 1, and thereafter, as the exposure is increased, that is, the color chart of this example is negative. Since it is made of a photosensitive material, the mantissa i is increased as the brightness decreases. (That is, the mantissa i increases as the density increases.) Thereafter, the Y image, M
When showing an image, a C image, an R image, a B image, a G image, and an N image, respectively, the Y image is Y, the M image is M, the C image is C,
The R image is represented by R, the B image is represented by B, the G image is represented by G, the N image is represented by N, and when these images are represented by symbols, they are represented by provisional characters k. Note that J ** in FIG. 6 is a symbol used in the following description.

Next, in FIG. 5S22, the image reading device 22 for calculation calculates the Y image (Yi: i = 1 to 15) and the M image (Mi: i) of each stage of the color chart 26 as shown in FIG. = 1 to 1
5), C image (Ci: i = 1 to 15), R image (Ri:
i = 1-15), B image (Bi: i = 1-15), G image (Gi: i = 1-15) and N image (Ni: i = 1-1)
5), and read the color input image information (JRki, JGki, JBki: k =
Y, M, C, B, G, R, N, i = 1 to 15).
In FIG. 6, JRki, JGki, and JBki are collectively referred to as Jki (k = Y, M, C, B, G, R, N, i =
1 to 15).

Next, in FIG. 5S23, a Y image (Yi: i = 1 to 1) of the color chart 26 obtained by the calculation image reading device 22 is obtained.
5), M image (Mi: i = 1 to 15), C image (Ci:
i = 1 to 15), R image (Ri: i = 1 to 15), B image (Bi: i = 1 to 15), G image (Gi: i = 1 to 1)
5) and color input image information (JRki, JGki, JBk) of R, G, B primary colors of N images (Ni: i = 1 to 15)
i: k = Y, M, C, B, G, R, N, i = 1 to 15)
Is input to the calculation image processing device 23 through the data interface.

Next, in S24 of FIG. 5, the calculation image processing device 23 converts the input color input image information into color output image information as it is. That is, color output image information is obtained without performing image processing on the color input image information. Then, the obtained color output image information is output to the calculation image forming apparatus 24 through the data interface.

Next, at S25 in FIG. 5, the calculation image forming apparatus 24 creates the second color chart 25 as shown in FIG. 6 from the color output image information sent from the calculation image processing apparatus 23. In FIG. 6, each of the 15 levels of density is indicated by a mantissa i, and the mantissa i increases as the density increases. In the following, Y image, M image, C image, R image,
When the B image, the G image, and the N image are indicated, respectively, the Y image is indicated by Y, the M image is indicated by M, the C image is indicated by C, the R image is indicated by R, the B image is indicated by B, the G image is indicated by N, and the N image is indicated by N. When these images are represented by symbols, they are represented by provisional characters k. Note that Q ** in FIG. 6 is a symbol used in the following description.

Next, in FIG. 5S26, the B, G, and R input image information of each image of the second color chart 25 is read by the calculation image reading device 22 as in FIG. 5S22. The input image information of the Y image (Yi: i = 1 to 15) read here is represented by QRYi,
QGYi, QBYi (i = 1 to 15) and M image (M
i: i = 1 to 15) is input as QRMi, QGM
i, QBMi (i = 1 to 15) and a C image (Ci: i =
QRCi, QGCi, QB
Ci (i = 1 to 15) and an R image (Ri: i = 1 to 1)
The input image information of 5) is QRRi, QGRi, QBRi.
(I = 1 to 15) and the input image information of the B image (Bi: i = 1 to 15) are represented by QRBi, QGBi, QBBi (i = 1
15) and the input image information of the G image (Gi: i = 1 to 15) as QRGi, QGGi, QBGi (i = 1 to 15).
And the input image information of the N image (Ni: i = 1 to 15) is Q
RNi, QGNi, and QBNi (i = 1 to 15). In FIG. 6, QRki, QGki, and QBki are collectively denoted by Qki (k = Y, M, C, R, G, B, N).

Next, in step S27 in FIG.
The input image information of each image of the second color chart 25 obtained in step 2 is input to the calculation image processing device 23 through the data interface.

Next, in S28 of FIG. 5, the calculation image processing device 23 converts the conversion function fi forming the deviation density conversion information.
Find j (). In the case where the degree of color enhancement in the high chroma portion is weakened as compared with the low chroma portion, a function having the following characteristics is used, for example. In the following description, Δx is Δ
It is treated as indicating any of R, ΔG, and ΔB.

Regarding frr (ΔR) regarding ΔR ′,
This is a function that reduces the amount of increase in the high chroma portion (ΔR ≧ a1, ΔR ≦ a2 in FIG. 7) with respect to the low chroma portion (a2 ≦ ΔR ≦ a1), as shown in FIG. A function with a perfect shape is preferred.

Further, frg (ΔG), frb regarding ΔR ′
Regarding (ΔB), a function having a shape as shown in FIG. 7 is preferable, and frg (Δx) = frb (Δx) may or may not be satisfied.

As for fgg (ΔG) regarding ΔG ′,
This is a function that reduces the amount of increase in the high saturation portion (ΔG ≧ a1, ΔG ≦ a2 in FIG. 7) with respect to the low saturation portion (a2 ≦ ΔG ≦ a1 in FIG. 7). A function with a perfect shape is preferred.

Further, fgb (ΔB), fgr regarding ΔG ′
(ΔR) is preferably a function having a shape as shown in FIG. 7, and fgb (Δx) = fgr (Δx) may or may not be satisfied.

For fbb (ΔB) related to ΔB ′,
This is a function that reduces the amount of increase in the high saturation portion (ΔB ≧ a1, ΔB ≦ a2 in FIG. 7) with respect to the low saturation portion (a2 ≦ ΔB ≦ a1 in FIG. 7). A function with a perfect shape is preferred.

Further, fbg (ΔG), fbr
As for (ΔR), a function having a shape as shown in FIG. 7 is preferable, and fbg (Δx) = fbr (Δx) may or may not be satisfied.

In FIG. 7 described above, a1 represents frr (ΔR), frg (ΔG), frb (ΔB) and fgr (Δg).
R), fgg (ΔG), fgb (ΔB), fbr (ΔR), f
It is preferable that all nine functions of bg (ΔG) and fbb (ΔB) are equal, but they do not necessarily have to be the same. The same applies to a2. Also, a1 and a2
Are desirably equal, but may be different.

When simply adjusting the saturation without adjusting the color tone, i = r, g, b, j = r, g, b, where i ≠ j,
When any one of Δx = ΔR, ΔG, and ΔB is set, fij (Δx) = 0 can also be set.

A function A as shown by a solid line in FIG. 8 is used to brighten a high chroma portion, and a function as a broken line B in FIG. 8 is used to darken a high chroma portion. Next, at S29 in FIG. 5, the calculation image processing device 23 sets the respective functions frr (ΔR) to fbb (ΔB) as deviation density conversion information and the deviation density conversion information and [4. Creation of Neutral Color Contrast Conversion Information] is stored in the conversion information storage medium 17.

[4. Creation of neutral color shading amount conversion information] [3. Creation of Deviation Shading Amount Conversion Information] in FIG. 5, the N images (Ni: i = 1 to 1) of each stage of the color chart 26 obtained in S22
5) R, G, B primary color input image information (JRN
i, JGNi, JBNi: i = 1 to 15) and FIG.
N image (Ni: i = 1) of each stage of the color chart 26 obtained in
15) R, G, B primary color input image information (QR
Ni, QGNi, QBNi: i = 1 to 15), the neutral color shading amount conversion information is obtained by the following equation.

[0112]

(Equation 1)

[Other Embodiments] In the above embodiment, when obtaining color output image information from color input image information, the deviation density conversion information read from the storage medium and the neutral color Although the gray level conversion information is used as it is, the deviation gray level conversion information and the neutral color gray level conversion information read from the storage medium may be corrected and used. In particular, when the fluctuation of the image forming apparatus or the material for the pictorial hard copy is remarkable compared with the accuracy of the target color output image information, it is preferable to correct the influence.

[0114]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A color correction method described in Japanese Patent Application Laid-Open No. 9-294215 filed separately by the applicant of the present application.
The above-described embodiment is applied to an image system similar to that of the first embodiment of the color correction apparatus. The same process is performed until a digital original image is created from the color negative film, neutralized and converted to obtain a color-corrected image, and color conversion using the equation of FIG. 7 in the embodiment of the present invention is performed. After that, the subsequent processes of the first embodiment described in the publication were performed.

As a result, it was confirmed that the image system according to the first embodiment described in the publication can obtain an image with little color collapse and high saturation, and it was confirmed that the effects of the present invention were sufficiently exhibited. .

[0116]

According to the present invention, the color conversion and the matrix operation are performed on the color components by dividing the color components into neutral density (input neutral color density) and color components (R, G, B input deviation density). Then, in the image processing for adding to the neutral density, each element of the matrix operation is not a simple constant but a function of a color component or L
It is possible to remove color turbidity from the color components by emphasizing only the colors by a matrix operation using a function of the color components and comprising a UT.

Accordingly, the R, G, and B colors that can preferably reproduce the original image from the R, G, and B color input image information of the original image while reducing the occurrence of color collapse even in a high chroma portion with a small amount of calculation.
B color output image information can be obtained.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating an outline of processing blocks of an image processing apparatus according to a first embodiment.

FIG. 2 is a flowchart of creating a pictorial hard copy according to the first embodiment;

FIG. 3 is a diagram illustrating an image reproduction system according to the first embodiment.

FIG. 4 is a diagram illustrating a conversion information creation system according to the first embodiment;

FIG. 5 is a flowchart illustrating a manner of creating deviation density conversion information in the first embodiment;

FIG. 6 is an explanatory diagram illustrating an example of a color chart according to the first embodiment.

FIG. 7 is a characteristic diagram illustrating an example of characteristics of a function constituting deviation density conversion information according to the first embodiment;

FIG. 8 is a characteristic diagram showing a characteristic example of a function constituting deviation density conversion information according to the first embodiment;

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 color image (original image) 12 image reading device 13 image processing device 14 image forming device 15 pictorial real copy 17 conversion information storage medium 19 storage medium reading device 22 calculation image reading device 23 calculation image processing device 24 calculation image formation Apparatus 25 Second color chart 26 Color chart 28 Image reading device 29 Storage medium writing device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shoichi Nomura 1 Sakuracho, Hino-shi, Tokyo Konica Corporation F-term (reference) 5B057 AA11 CA01 CA08 CA12 CB01 CB08 CB12 CE17 CH08 DB02 DB06 DB09 5C077 LL19 MM27 MP08 PP32 PP33 PP37 PP39 PQ12 PQ23 TT02 5C079 HB01 LB01 MA11 NA02 NA03

Claims (4)

[Claims] 1. An image processing method for obtaining R, G, B color output image information from R, G, B color input image information of an original image, comprising: Neutral color shading amount and input deviation shading amount of R, G, B are obtained. Based on neutral color shading amount conversion information, output neutral color shading amount is obtained from the obtained input neutral shading amount. The output deviation density of R, G, B is calculated from the input deviation density of R, G, B by the deviation density conversion formula of, the output neutral color density obtained and the output of R, G, B obtained An image processing method, wherein R, G, B color output image information is obtained from the deviation shading amount. ΔR ′ = frr (ΔR) + frg (ΔG) + frb (ΔB) ΔG ′ = fgr (ΔR) + fgg (ΔG) + fgb (ΔB) ΔB ′ = fbr (ΔR) + fbg (ΔG) + fbb (ΔB) Here, the input deviation The gray level is ΔR, ΔG, ΔB, the output deviation gray level is ΔR ′, ΔG ′, ΔB ′, and the conversion function is fij ().
And let ij be {r, g, b}. 2. The image processing method according to claim 1, wherein the deviation density conversion formula is independent for each combination of signs of the input deviation density of R, G, and B. 3. An image processing apparatus for obtaining R, G, B color output image information from R, G, B color input image information of an original image, comprising: An input calculating means for obtaining a neutral color shading amount and an input deviation shading amount of R, G, B; an output from the input neutral color shading amount obtained by the input calculating means based on the neutral color shading amount conversion information Neutral color shading amount calculating means for obtaining neutral color shading amount, and deviation shading for obtaining output deviation shading amounts of R, G, B from input deviation shading amounts of R, G, B by the following deviation shading amount conversion formula. From the output neutral color shading amount obtained by the neutral color shading amount calculating means and the R, G, B output deviation shading amount obtained by the deviation shading amount calculating means. An output processing means for obtaining color output image information. ΔR ′ = frr (ΔR) + frg (ΔG) + frb (ΔB) ΔG ′ = fgr (ΔR) + fgg (ΔG) + fgb (ΔB) ΔB ′ = fbr (ΔR) + fbg (ΔG) + fbb (ΔB) Here, the input deviation The gray level is ΔR, ΔG, ΔB, the output deviation gray level is ΔR ′, ΔG ′, ΔB ′, and the conversion function is fij ().
And let ij be {r, g, b}. 4. The image processing apparatus according to claim 1, wherein the deviation density conversion formula is independent for each combination of signs of R, G, and B input deviation density.