KR20010064277A - Non-linear gamut compression device and method using multiple-convergent points - Google Patents

Abstract

PURPOSE: A non-linear color gamut compression apparatus and a method using multi-convergent points are respectively provided to make a color of an image displayed on a display apparatus equal to an original image by using a non-linear, multi-convergent type. CONSTITUTION: The non-linear color gamut compression apparatus using multi-convergent point includes a color transforming part(210), a color gamut compression part(220), and a color information reverse transforming part(230). The color transforming part(210) transforms red, green and blue input variables into luminance and chrominance variables. The color gamut compression part(220) non-linearly compresses color information inputted from the color transforming part(210) and performs the luminance-chrominance gamut compression based on a multi-convergent point. And, the color information reverse transforming part(230) converts the compressed luminance and chrominance variables by the color gamut compression part(220) into magenta, yellow and black color coordinates.

Description

Non-linear color gamut compression apparatus and method using multiple convergence points {NON-LINEAR GAMUT COMPRESSION DEVICE AND METHOD USING MULTIPLE-CONVERGENT POINTS}

The present invention relates to a nonlinear color gamut compression apparatus using multiple convergence points, wherein the color reproduction region of a color display and an input device is printed as the color reproduction area of the input device is relatively larger than that of the output color printing device. The present invention relates to a nonlinear color gamut compression device using multiple convergence points, which improves accuracy by allowing uncolored color areas to be matched to color images seen in original and display equipment based on human viewing characteristics as much as possible.

In recent years, the field of color reproduction is increasing in importance as the demand for color equipment such as color scanners, monitors, and printers increases. In particular, the field of color reproduction is highly utilized by color equipment manufacturers. It is nurturing.

In the field of color representation in the related art, a method of finding colors that cannot be printed or relatively cutting out colors in a color gamut has been utilized by many years of professional experience.

However, such a conventional method, such as the deterioration of the quality of the prints printing colors different from the original, the waste of unnecessary resources such as excessive use of the print paper, the difficulty of transferring the technology by the experience method, the excessive processing time that must go through trial and error every time, etc. There was a downside.

Therefore, the present invention is based on the human gaze characteristics to compensate for the above disadvantages, the part that can not express the color from the wide color gamut of the output color printing equipment from the wide color gamut of the color display and the input equipment It is an object of the present invention to provide an apparatus for printing a color that matches the color of an image shown on a display device by using a nonlinear method using multiple convergence.

1 illustrates a configuration in which a nonlinear color gamut compression device using multiple convergence points according to an embodiment of the present invention is positioned between a color display and an input device and an output color printing device,

2 shows color information converting means according to an embodiment of the present invention,

3 illustrates a color gamut compression means according to an embodiment of the present invention,

4 is a flowchart illustrating an operation of a color gamut compression means according to an embodiment of the present invention;

5 illustrates a concept of non-linearly performing color gamut width compression of luminance in a color gamut width compression unit among color gamut width compression means according to an embodiment of the present invention;

FIG. 6 illustrates a concept in which a luminance-saturation color gamut width compression unit of a color gamut compression unit according to an embodiment of the present invention performs luminance-saturation gamut width compression using multiple convergence points,

7 illustrates a color information inverse converting means according to an embodiment of the present invention.

*. Explanation of references to the main parts of the drawings

100: color display and input equipment

200: color gamut compression device

210: color information conversion means

220: color gamut compression means

230: reverse color information conversion means

300: color output device

From this, the nonlinear color gamut compression apparatus using the multi-convergence point provided by the present invention includes coordinate input parameters of red, green, and blue, which are images of the color display and the input device 100. Color information converted to color coordinates of luminance (L *), saturation (C *), and hue (h *) through tristimulus values (X, Y, Z) and the color coordinate system of CIE L *, a *, b * A color gamut width that performs non-linear gamut width compression of luminance from the color means converted from the color information conversion means 210 and color gamut width compression of luminance-saturation around a multi-convergence point. Color printing of the compression means 220 and the luminance (L *), the compressed luminance-saturation (L * -C *), and the color (h *) compressed by the color gamut compression means 220 again. It includes a color information inverse conversion means 230 for converting the color coordinates of cyan, magenta, yellow, and black that can be used in the equipment 300. It is characterized by losing.

In addition, in the nonlinear color gamut compression method using multiple convergence points provided by the present invention, three color coordinate input variables of red, green, and blue, which are images of the color display and the input device 100, are used. A first step of converting the color coordinates of luminance (L *), saturation (C *) and hue (h *) through the coordinate system of extreme values (X, Y, Z) and CIE L *, a *, b *; And a second step of performing non-linear color gamut compression of luminance from the converted color information and performing color gamut width compression of luminance-saturation around a multi-convergence point, and the compressed luminance L * is compressed. Cyan, Magenta, Yellow, Black, which can use the luminance-saturation (L * -C *) and hue (h *) parameters again in the color output printing equipment 300 It comprises a third step of converting the color coordinates of the configuration.

In addition, the nonlinear color gamut compression method using multiple convergence points provided in the present invention is characterized by recording on a recording medium in the form of a program to be executed by a computer.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

1 illustrates a configuration in which a nonlinear color gamut compression device using multiple convergence points according to an embodiment of the present invention is positioned between a color display and an input device and an output color printing device.

The nonlinear color gamut width compression device 200 using the multiple convergence points according to the present invention includes a color information conversion means 210, a color gamut width compression means 220, and a color information inverse conversion means 230.

Coordinate input variables of red, green, and blue colors, which are images of the color display and the input device 100, are converted into tristimulus values (X, Y, Z) through the color information converting means 210. Converted to color coordinates of luminance (L *), saturation (C *), and hue (h *) through the L *, a *, b * color coordinate system of the Commission for International Lighting (hereinafter referred to as CIE). do.

The color information converted by the color information converting means 210 performs non-linear color gamut width compression of the luminance through the color gamut compression means 220 and performs color gamut width compression of the luminance-saturation centering on multiple convergence points. .

Cyan, which is a color coordinate that can be used by the color gamut compression means 220 again to output the variable of luminance L *, compressed saturation L *, and color h *. (Cyan), magenta (Magenta), yellow (Yellow), and black (Black) are converted back through the color information inverse converting means 230.

2 shows color information converting means according to an embodiment of the present invention.

The color information converting means 210 is largely composed of three look-up tables. The first is a luminance value L * generation lookup table 211, the second is a saturation value C * generation lookup table 212, and the third is a color value h * generation lookup table 213.

The lookup table is based on the color display system of the color display and the device dependent color coordinates of the input device 100, that is, the red, green, and blue color coordinate systems. The color coordinate system is converted into device independent CIE XYZ coordinates, and the information is converted into information of luminance (L *), saturation (C *) and hue (h *).

log Tr = c1r log [(1- c2r) D + c2r]

log Tg = c1g log [(1- c2g) D + c2g]

log Tb = c1b log [(1- c2b) D + c2b]

Luminance (L *) = 116 * (Y / Yn) 1/3 16.0 (Y / Yn> 0.008856)

Luminance (L *) = 903.3 * (Y / Yn) 1/3 (Y / Yn <= 0.008856)

a * = 500 * [(X / Xn) 1/3-(Y / Yn) 1/3]

b * = 200 * [(Y / Yn) 1 / 3- (Z / Zn) 1/3]

Saturation (C *) = (a * a * + b * b *) 2

Color (h *) = Actan (b * / a *)

Here, xr, yr, zr are chromaticity of color when a signal of 255 for Red Gun, 0 for Green Gun, and 0 for Blue Gun is given in the display equipment. , xb, yb, zb are the measurement of color when a signal of red is 0, green is 0, and blue is 255 at the display device, and xg, yg, zg are 0, green at the red gun on the display device. When 255 is applied to the gun and 0 signal is given to the blue gun, Tr, Tg, and Tb represent the red, green, and blue luminance values of the CRT monitor.

In addition, C1r, C2r, C1g, C2g, C1b, and C2b are the Optimization Coefficients of the functions related to the corresponding Red, Green, and Blue guns.

Figure 3 illustrates a color gamut compression means according to an embodiment of the present invention.

The gamut width compression unit 220 compresses the luminance gamut width compression unit 211 and the luminance gamut width compression unit 211 to non-linearly compress the luminance received from the color information conversion unit 210. The luminance-saturation color gamut width compression unit 212 and the luminance color gamut width compression unit 211 and the luminance-saturation that perform compression of the received luminance and the saturation received from the color information converting means 210 around multiple convergence points. A gamut width information storage unit 213 is provided to provide gamut width information necessary for performing the gamut width compression unit 212.

4 is a flowchart illustrating an operation of a color gamut compression means according to an embodiment of the present invention.

The color information converting means 210 receives the information of luminance L *, saturation C *, and hue h * (S410).

First, luminance compression is performed among the input variables (S420), and it is determined whether chroma information is 1.0 or less (S430).

As a result of the determination, if the saturation information is 1.0 or less, the saturation information is transmitted to the color information inverse converting means 230 without further compression.

If the saturation information is 1.0 or more, the color gamut information storage unit 213 determines whether the saturation corresponding to the image color on the limit color gamut width information of the color output printing apparatus 300 is 75% or less (S450).

As a result of the determination, if the saturation is less than or equal to 75%, the saturation is transmitted to the color information inverse converting means 230 without any further compression process (S470).

If the saturation is 75% or more, the chroma-to-saturation gamut width is compressed (S460), and then transmitted to the inverse color information converting means 230 (S470).

5 illustrates a concept of non-linearly performing color gamut width compression of luminance in a color gamut width compression unit among color gamut width compression means according to an embodiment of the present invention.

Referring to FIG. 5, the input luminance of the horizontal axis using one linear function is not deformed to the luminance processed on the vertical axis, and two different linear functions using the B point as an inflection curve, thus a nonlinear function as a whole. Will be used.

This shows that a function of low compression is used in dark areas having low luminance and high compression is used in bright areas having high luminance.

Here, the horizontal axis represents the luminance value input from the color gamut conversion means 210 and the vertical axis represents the compressed luminance value to be processed.

In the luminance gamut width compression unit 221, Ax of the point A is a minimum luminance value that can be expressed by the input display device 100, and Ay is a minimum luminance value that can be expressed by the output printing device 300.

Among these, Bx and By of the nonlinear bending point B are determined by the following equation.

By = Ay

Bx = (Cx-Ax) /5.26

Here, Cx is a maximum luminance value that can be represented by the input display equipment.

FIG. 6 illustrates a concept in which a luminance-saturation color gamut width compression unit of the color gamut width compression unit according to an embodiment of the present invention performs luminance-saturation color gamut width compression using multiple convergence points.

In the above, the vertical axis represents luminance (L *) and the horizontal axis represents chroma (C *). In addition, A is the convergence point of the upper luminance region proposed by the present invention, B is the convergence point of the lower luminance region proposed by the present invention, C is color gamut boundary information unique to the output device, that is, the color that the output device can display at the maximum. Boundary area, D is the gamut width information unique to the input / display device, that is, the boundary area of the color that the input / display device can represent the maximum, E is the luminance value (L * of Cusp) of the maximum chroma point of C, The luminance value having the saturation point that the output device can express the maximum, F denotes the luminance value Cus of the maximum saturation point of D, that is, the luminance value having the saturation point that the input device can express the maximum.

In detail, this will be described in detail with reference to FIG. 6. In consideration of only luminance and saturation based on a specific hue (for example, at a red color of 45 degrees), the input device reproduces colors at maximum. If the border information is D and the output device reproduces the maximum color as C, if all colors outside the area of C are reproduced with the output device (for example, when printing a color image of the monitor) No output

Therefore, the color outside the region of C must be compressed using a specific method. In this case, the present invention has three compression directions (converging directions), so that the index having a luminance greater than or equal to A point (that is, brighter than A point) is obtained. To point A (to convergence point), to an index with a luminance less than or equal to B (i.e., darker than point B), to point B (to convergence point), parallel to the horizontal axis (saturation) for other indexes. Perform compression.

By using this, a mechanism for performing color gamut compression can be expressed by the following equation. (1) and (2) are equations for determining multiple convergence points.

(1) The convergence point of the lower luminance region is determined by using the luminance L * compressed by the luminance gamut width compression unit 221.

If D <30.0 the convergence luminance point (L *) of B = 28.0;

Otherwise

Convergence luminance point of B (L *) = 19.17 × e ^{0.0124 × D luminance value}

(2) The convergence point of the upper luminance region is determined by using the luminance L * compressed by the luminance gamut width compression unit 221.

If D <30.0 the convergence luminance point (L *) of A = 75.0;

Otherwise

Convergence Luminance Point of A (L *) = 0.0002 × D ³ + 0.0289 × D ² + 1.4559 × D + 51.872

(3) Otherwise

The gamut width compression is performed horizontally on the horizontal axis (saturation axis) by using the luminance L * compressed by the luminance gamut width compression unit 221.

The gamut width information storage unit 223 stores gamut information that can be displayed by a display and a printing device in a binary file form, and the luminance gamut width compression unit 221 and luminance-saturation are stored. The gamut width compression unit 222 transmits marginal gamut boundary information during processing.

7 illustrates a color information inverse converting means according to an embodiment of the present invention.

The color information inverse converting means 230 converts the information of luminance L *, saturation C *, and color h * converted by the color gamut compression means 220 into three lookup tables 231 and 232 ( 233 converts the information to cyan, magenta, yellow, and black so that the color printing output device 300 can print.

In detail, the matrix used in the lookup table 211, 212, and 213 used in the color information converting unit 210 mathematically takes an inverse matrix, and is also obtained through this inverse matrix. Three lookup tables can be constructed by using the Tristimulus value using the Device Color Character function of the output device.

The device color characteristic function of this output device can be defined as follows.

C = a11 × X + a12 × Y + a13 × Z

M = a21 × X + a22 × Y + a23 × Z

Y = a31 × X + a32 × Y + a33 × Z

K = a41 × X + a42 × Y + a43 × Z

Where X, Y, and Z are Tristimulus values derived from the inverse matrix, and K is used as an abbreviation of black, and {a11, a12, a13, a21, a22, a23, a31, a32, a33, a41, a42, a43} can be said to form a parameter. This can be taken from the gamut width information storage unit 223.

Although the present invention has been described above based on examples, these examples are intended to illustrate the present invention without restricting the invention, and various modifications may be made within the scope of the technical idea intended by the present invention to those skilled in the art. Can be modified.

As described above, the present invention provides a non-linear, multi-convergence method based on human viewing characteristics in a color gamut that cannot be reproduced due to a difference in gamut width when inputting to an input color device or outputting a color image shown on a display device. Use to match the color of the original image as much as possible.

Therefore, accuracy is reconsidered and may be used to print colors that match the color of the display equipment, such as color monitors in the graphics, image processing, virtual reality and printing industries, as closely as possible. It can be used to reproduce optimal colors in development.

In addition, it can be used as an application library of the Color Management System that minimizes color information discrepancies between information providers and end users in high-speed information and communication networks.

Claims (16)

The red, green, and blue coordinate input parameters of the color display and the input device 100, the tristimulus values (X, Y, Z) and CIE L *, a *, b * Color information converting means 210 for converting color coordinates of luminance (L *), saturation (C *), and hue (h *) through a color coordinate system of A gamut width compression means 220 for performing non-linear gamut width compression of luminance from color information transmitted from the color information converting means 210 and performing gamut width compression of luminance-saturation centered on multiple convergence points; Variables of the luminance (L *), the compressed luminance-saturation (L * -C *), and the color (h *) compressed by the gamut width compression means 220 may be used again in the output color printing apparatus 300. Non-linear color gamut compression apparatus using multiple convergence points, characterized in that it comprises a color information inverse conversion means 230 for converting the color coordinates of cyan, magenta, yellow, and black . The method of claim 1, wherein the color information converting means 210, A luminance value L * generation lookup table 211, a saturation value C * generation lookup table 212 and a color value (h *) generation lookup table 213 are used as the luminance L * and saturation C *. ), And the color coordinate system of red, green, and blue, which are the device-dependent color coordinates of the color display and input device 100, is converted into the following information. A nonlinear color gamut compression device using multiple convergence points, characterized by converting into device independent CIE XYZ coordinates using an equation. log Tr = c1r log [(1- c2r) D + c2r] log Tg = c1g log [(1- c2g) D + c2g] log Tb = c1b log [(1- c2b) D + c2b] Luminance (L *) = 116 * (Y / Yn) 1/3 16.0 (Y / Yn> 0.008856) Luminance (L *) = 903.3 * (Y / Yn) 1/3 (Y / Yn <= 0.008856) a * = 500 * [(X / Xn) 1/3-(Y / Yn) 1/3] b * = 200 * [(Y / Yn) 1 / 3- (Z / Zn) 1/3] Saturation (C *) = (a * a * + b * b *) 2 Color (h *) = Actan (b * / a *) Here, xr, yr, zr are chromaticity of color when a signal of 255 for Red Gun, 0 for Green Gun, and 0 for Blue Gun is given in the display equipment. , xb, yb, zb are the measurement of color when a signal of red is 0, green is 0, and blue is 255 at the display device, and xg, yg, zg are 0, green at the red gun on the display device. When 255 is given to the gun and 0 signal is given to the blue gun, Tr, Tg, and Tb are the red, green, and blue luminance values of the CRT monitor. In addition, C1r, C2r, C1g, C2g, C1b, and C2b are the Optimization Coefficients of the functions related to the corresponding Red, Green, and Blue guns. The method of claim 1, wherein the color gamut compression means 220, A luminance gamut width compressing unit 211 for performing non-linear compression of the luminance received from the color information converting means 210; A luminance-saturation color gamut width compression unit 212 which performs compression of the luminance compressed by the luminance gamut width compression unit 211 and the saturation input from the color information conversion means 210 around a multi-convergence point; Using a multi-convergence point, characterized in that it comprises a gamut width information storage unit 213 for providing the gamut width information necessary to perform the luminance gamut width compression unit 211 and the luminance-saturation color gamut width compression unit 212 Nonlinear color gamut compression device. The method of claim 3, wherein the color gamut information storage unit 223, The gamut information displayed by the display or the printing equipment can be stored in the form of a binary file, and the luminance gamut width compression unit 221 and the luminance-saturation color gamut width compression unit 222 are required for processing. A nonlinear gamut compression device using multiple convergence points, characterized by sending marginal gamut boundary information. The method of claim 3, wherein the luminance gamut width compression unit 211, A nonlinear color gamut compression device using multiple convergence points, characterized in that Bx, By of a nonlinear bending point B is determined by the following equation to compress luminance. By = Ay Bx = (Cx-Ax) /5.26 Here, Ax of the point A is the minimum luminance value that can be expressed by the input display equipment 100, Ay is the minimum luminance value that can be expressed by the output printing equipment 300, Cx is the maximum luminance value that can be expressed by the input display equipment. . The method of claim 3, wherein the luminance-saturation color gamut width compression unit 223, When the convergence point of the lower luminance area is D <30.0 using the luminance L * compressed by the luminance gamut width compression unit 221, the convergence luminance point L * of B is 28.0. Convergence luminance point of B (L *) = 19.17 × e ^{0.0124 × D} , and if the convergence point of the upper luminance region is D <30.0, then convergence luminance point (L *) = 75.0, otherwise Is determined by the convergence luminance point (L *) of A = 0.0002 × D ³ + 0.0289 × D ² + 1.4559 × D + 51.872. Otherwise, color gamut compression is performed horizontally on the chroma axis. Nonlinear color gamut compression device using multiple convergence points. Where A is the upper luminance region convergence point, B is the lower luminance region convergence point, C is the output gamut gamut boundary information, D is the input / display device gamut gamut boundary information, and E is the luminance value of the maximum chroma point (L). * of Cusp), F is the luminance value Cusp of the maximum chroma point of D. According to claim 1, wherein the color information inverse conversion means 230, Color printing output equipment through the three lookup tables (231, 232, 233) information of the luminance (L *), saturation (C *) and hue (h *) converted by the gamut width compression means (220) Non-linear color using multiple convergence points, characterized by inverting the information of cyan, magenta, yellow, and black by using the following color characteristic function for printing at 300 Reverse width compression device. C = a11 × X + a12 × Y + a13 × Z M = a21 × X + a22 × Y + a23 × Z Y = a31 × X + a32 × Y + a33 × Z K = a41 × X + a42 × Y + a43 × Z X, Y, and Z are tristimulus values derived from the inverse matrix, and K is used as an abbreviation of black, and {a11, a12, a13, a21, a22, a23, a31, a32, a33, a41, a42, a43} are the parameters that make up the function. The color coordinate input parameters of red, green, and blue, which are images of the color display and the input device 100, are determined using the tristimulus values (X, Y, Z) and CIE L *, a *, b *. A first step of converting color coordinates of luminance (L *), saturation (C *), and hue (h *) through a color coordinate system; A second step of performing non-linear gamut width compression of luminance from the converted color information and performing gamut width compression of luminance-saturation centered on multiple convergence points; Cyan and Magenta, which may use the compressed luminance (L *), compressed luminance-saturation (L * -C *), and hue (h *) parameters again in the color output printing apparatus 300 And a third step of converting the color coordinates into yellow and black color coordinates. The method of claim 8, wherein the conversion of the luminance (L *), the saturation (C *), the hue (h *) to the color coordinates of the first step is The color coordinate system of red, green, and blue, which are device dependent color coordinates of the color display and input device 100, is determined using the following equation. Device Independent CIE XYZ coordinates And converting the information into luminance (L *), saturation (C *), and color (h *) information. log Tr = c1r log [(1- c2r) D + c2r] log Tg = c1g log [(1- c2g) D + c2g] log Tb = c1b log [(1- c2b) D + c2b] Luminance (L *) = 116 * (Y / Yn) 1/3 16.0 (Y / Yn> 0.008856) Luminance (L *) = 903.3 * (Y / Yn) 1/3 (Y / Yn <= 0.008856) a * = 500 * [(X / Xn) 1/3-(Y / Yn) 1/3] b * = 200 * [(Y / Yn) 1 / 3- (Z / Zn) 1/3] Saturation (C *) = (a * a * + b * b *) 2 Color (h *) = Actan (b * / a *) Here, xr, yr, zr are chromaticity of color when a signal of 255 for Red Gun, 0 for Green Gun, and 0 for Blue Gun is given in the display equipment. , xb, yb, zb are the measurement of color when a signal of red is 0, green is 0, and blue is 255 at the display device, and xg, yg, zg are 0, green at the red gun on the display device. When 255 is given to the gun and 0 signal is given to the blue gun, Tr, Tg, and Tb are the red, green, and blue luminance values of the CRT monitor. In addition, C1r, C2r, C1g, C2g, C1b, and C2b are Optimization Coefficients of functions related to the corresponding red, green, and blue guns. The method of claim 8, wherein the color gamut compression of the second stage, A first sub-step of receiving the converted luminance (L *), saturation (C *), and color (h *) information and performing luminance compression; A second sub-step of determining whether the chroma information is 1.0 or less, and inversely converting the color information without further compression if the chroma information is 1.0 or less; If the saturation information is 1.0 or more, it is determined whether the saturation corresponding to the image color on the color gamut width information of the color output printing equipment 300 is 75% or less. If the saturation is 75% or less, the color is not subjected to any further compression. A nonlinear color gamut compression method using multiple convergence points, comprising: a third sub-step of inversely transforming information, compressing the luminance-saturation color gamut width when the chroma is more than 75%, and then inversely converting the color information. The method of claim 10, wherein the compression of the luminance in the first sub-step, A nonlinear color gamut compression method using multiple convergence points, wherein the Bx and By of the nonlinear bending point B are determined by the following equation. By = Ay Bx = (Cx-Ax) /5.26 Here, Ax of the point A is the minimum luminance value that can be expressed by the input display equipment 100, Ay is the minimum luminance value that can be expressed by the output printing equipment 300, Cx is the maximum luminance value that can be expressed by the input display equipment. . 11. The method of claim 10, wherein the third sub-step luminance-saturation color gamut compression is By using the luminance L * compressed in the first sub-step, the convergence point of the lower luminance region is set to the convergence luminance point L * of B = 28.0 when D <30.0. Otherwise, the convergence luminance of B is otherwise. The point (L *) = 19.17 × e ^{0.0124 × D. The} convergence point of the upper luminance area is D <30.0, and the convergence luminance point (L *) = 75.0 in other cases. Determine the luminance point (L *) = 0.0002 × D ³ + 0.0289 × D ² + 1.4559 × D + 51.872. Otherwise, multi-convergence point is characterized by performing color gamut compression on the chroma axis horizontally. Nonlinear color gamut compression method. Where A is the upper luminance region convergence point, B is the lower luminance region convergence point, C is the output gamut gamut boundary information, D is the input / display device gamut gamut boundary information, and E is the luminance value of the maximum chroma point (L). * of Cusp), F is the luminance value Cusp of the maximum chroma point of D. The gamut width information of the third sub-step, wherein: Marginal Gamut Boundary Information for storing gamut information that can be displayed by a display or a printing device in the form of a binary file, which is required for the luminance gamut width compression and the luminance-saturation gamut width compression. Nonlinear color gamut compression method using multiple convergence points characterized in that sent to. The method of claim 8, wherein the inverse color information conversion of the third step, Cyan by the following color characteristic function so that the information of the luminance (L *), saturation (C *) and hue (h *) converted by the color gamut compression can be printed by the color printing output device 300 ), A nonlinear color gamut compression method using multiple convergence points, characterized by inverse transformation into magenta, yellow, and black information. C = a11 × X + a12 × Y + a13 × Z M = a21 × X + a22 × Y + a23 × Z Y = a31 × X + a32 × Y + a33 × Z K = a41 × X + a42 × Y + a43 × Z Where X, Y, and Z are Tristimulus values derived from the inverse matrix, and K is used as an abbreviation of black, and {a11, a12, a13, a21, a22, a23, a31, a32, a33, a41, a42, a43} are parameters that form a function. On your computer, The color coordinate input parameters of red, green, and blue, which are images of the color display and the input device 100, are determined using the tristimulus values (X, Y, Z) and CIE L *, a *, b *. A first step of converting color coordinates of luminance (L *), saturation (C *), and hue (h *) through a color coordinate system; A second step of performing non-linear gamut width compression of luminance from the converted color information and performing gamut width compression of luminance-saturation centered on multiple convergence points; Cyan and Magenta, which may use the compressed luminance (L *), compressed luminance-saturation (L * -C *), and hue (h *) parameters again in the color output printing apparatus 300 A computer-readable recording medium having recorded thereon a program capable of executing a nonlinear gamut compression method using multiple convergence points, including a third step of converting the color coordinates of a yellow, yellow, and black color. The method of claim 15, wherein the second stage compression is A first sub-step of receiving the converted luminance (L *), saturation (C *), and color (h *) information and performing luminance compression; A second sub-step of determining whether the chroma information is 1.0 or less, and inversely converting the color information without further compression if the chroma information is 1.0 or less; If the saturation information is 1.0 or more, it is determined whether the saturation corresponding to the image color on the color gamut width information of the color output printing equipment 300 is 75% or less. If the saturation is 75% or less, the color is not subjected to any further compression. Inverting the information, and if the saturation is 75% or more saturation, the third step is to compress the luminance-saturation gamut width, and then inversely converts the color information. Recording media.