Information processing device, method, and program

Abstract

An information processing device according to an embodiment includes a calculating unit that calculates combinations of illuminating light and materials constituting one or more objects on the basis of the spectral reflectance of the materials, the spectral distribution of illuminating light, and a color matching function corresponding to the spectral sensitivity of the human eye, such that when illuminating light from an illuminating device comprising a combination of light sources that emit light having a first spectral distribution is emitted at the one or more objects, made from a plurality of materials having different spectral reflectances, a plurality of hues are perceived by an observer, and when, instead of emitting said light, illuminating light from an illuminating device comprising a combination of light sources that emit light having a second spectral distribution different from the first spectral distribution is emitted at the one or more objects, some of the plurality of hues are perceived as different hues by the observer.

Description

Information processing device, method and program

[0001] FIELD Embodiments of the present invention relate to an information processing device, method, and program.

[0002] Metamerism is a phenomenon in which a user perceives an object as a combination of colors with different spectral reflectances under one light source, but perceives only the same colors under another light source. Existing technologies relate to lighting effects, such as intentionally inducing or eliminating metamerism by controlling the illumination light spectrum.

[0003] While existing technologies have realized lighting effects that make "different colors appear to be the same color" or "the same color appear to be different colors" before and after a lighting change, they have not realized lighting effects that, when illuminating an object made up of multiple materials with different spectral reflectances, make it appear as if "only some of the hues perceived before the lighting change have changed to different hues after the lighting change," or make it appear as if "a first hue perceived before the lighting change has changed to a second hue perceived before the lighting change after the lighting change, and the second hue perceived before the lighting change has changed to the first hue perceived before the lighting change after the lighting change."

[0004] To achieve such lighting effects, it is necessary to find the appropriate combination of object and illumination light that will achieve the desired object color from among a huge number of combinations of the reflectance (spectral reflectance) of the object and the spectral power distribution (SPD) of the illumination light.

[0005] Furthermore, even if the desired combination of object and lighting is found, if the lighting color is colored light such as "red" or "blue" that is far removed from natural white, the color of parts of the object that should not be changed will also change. Also, even if the object is made of a single color, the change in lighting that is changing the object's color will be obvious to the viewer, which can reduce the viewer's surprise or excitement.

[0006] Non-Patent Document 1 describes a technology that controls the saturation (the vividness of the apparent color of a subject) while maintaining the light source color as natural white by changing the SPD of the illumination light through control of multiple light sources. This technology is, from a broad perspective, a technology that can control the apparent color of an object by the illumination light, in that it can increase or decrease the saturation of a specific color among RGB, for example.

[0007] M. Tsuchida, K. Hiramatsu, K. Kashino, “Designing Spectral Power Distribution of Illumination with Color Chart to Enhance Color Saturation,” in Proc. IS&T 24th Color and Imaging conference (CIC24), pp. 278-282, 2016.<https: / / www.rd.ntt / cs / event / openhouse / 2018 / exhibition / 15 / >

[0008] However, the above-mentioned Non-Patent Document 1 does not address the problem of making only a specific hue among a plurality of hues appear to have changed to a different hue through lighting control, i.e., making it appear that all hues other than a specific one among a plurality of hues have not changed to a different hue through lighting control, or making it appear that two different colors have been swapped through lighting control. Therefore, when lighting light is irradiated onto an object made of a plurality of materials having different spectral reflectances, it is not possible to find a combination of object and lighting light that would make it appear that "only some hues perceived before the lighting change have changed to different hues after the lighting change" or that "a first hue perceived before the lighting change has changed to a second hue perceived before the lighting change after the lighting change, and the second hue perceived before the lighting change has changed to the first hue perceived before the lighting change after the lighting change," and so there is room for improvement.

[0009] The present invention has been made in light of the above-mentioned circumstances, and its object is to provide an information processing device, method, and program that can appropriately control the hue perceived when illumination light is irradiated onto an object.

[0010] An information processing device according to one aspect of the present invention includes a calculation unit that calculates combinations of materials constituting an object and illumination light based on the spectral reflectances of the materials, the spectral distribution of the illumination light, and color-matching functions corresponding to the spectral sensitivity of the human eye, such that when illumination light from an illumination device constituted by a combination of light sources that emits light having a first spectral distribution is irradiated onto a single or multiple objects made of multiple materials with different spectral reflectances, a plurality of hues are perceived by an observer, and when illumination light from an illumination device constituted by a combination of light sources that emits light having a second spectral distribution different from the first spectral distribution is irradiated onto the objects instead of the first spectral distribution, some of the plurality of hues are perceived by the observer as different hues.

[0011] An information processing method according to one aspect of the present invention is a method performed by an information processing device, and includes calculating, by a calculation unit of the information processing device, combinations of materials constituting the object and illumination light such that, when illumination light from an illumination device constituted by a combination of light sources that emits light having a first spectral distribution is irradiated onto a single or multiple objects made of multiple materials with different spectral reflectances, a plurality of hues are perceived by an observer, and when illumination light from an illumination device constituted by a combination of light sources that emits light having a second spectral distribution different from the first spectral distribution is irradiated onto the object instead of this irradiation, some hues of the plurality of hues are perceived by the observer as different hues, based on the spectral reflectances of the materials, the spectral distribution of the illumination light, and color matching functions corresponding to the spectral sensitivity of the human eye.

[0012] According to the present invention, it is possible to appropriately control the hue that is perceived when illumination light is irradiated onto an object.

[0013] FIG. 1 is a diagram showing a first application example of an information processing device according to an embodiment of the present invention. FIG. 2 is a diagram showing a first example of a change in the hue of a material perceived by an observer when the illumination light is switched. FIG. 3 is a diagram showing a second example of a change in the hue of a material perceived by an observer when the illumination light is switched. FIG. 4 is a diagram showing a third example of a change in the hue of a material perceived by an observer when the illumination light is switched. FIG. 5 is a diagram showing a fourth example of a change in the hue of a material perceived by an observer when the illumination light is switched. FIG. 6 is a diagram showing an example of search conditions in a table format. FIG. 7 is a diagram showing an example of material information of the search conditions in a table format. FIG. 8 is a diagram showing an example of illumination light information of the search conditions in a table format. FIG. 9 is a diagram showing an example of spectral distribution data of illumination light for each light source in a table format. FIG. 10 is a diagram showing an example of color matching function data in a table format. FIG. 11 is a flowchart showing an example of processing operations by a calculation unit. FIG. 12 is a diagram showing a second application example of an information processing device according to an embodiment of the present invention. FIG. 13 is a flowchart showing an example of processing operations by an illumination control unit. FIG. 14 is a block diagram showing an example of the hardware configuration of an information processing apparatus according to an embodiment of the present invention.

[0014] An embodiment of the present invention will be described below. Fig. 1 is a diagram showing a first application example of an information processing device according to an embodiment of the present invention. The information processing device 100 shown in Fig. 1 includes a calculation unit 101, a light source information storage unit 103, a color matching function storage unit 104, a spectral reflectance storage unit 105, and an input unit 106. The function of each unit will be described in detail below.

[0015] In one embodiment of the present invention, when illumination light irradiating a single or multiple objects made of multiple materials with different spectral reflectances is switched from first illumination light having a first spectral distribution to second illumination light having a second spectral distribution different from the first spectral distribution, in a case where "some hues perceived by the observer before the illumination light is switched are perceived as having changed to different hues after the illumination light is switched" or "the first hue perceived by the observer before the illumination light is switched is perceived as having changed to the second hue perceived before the switch after the illumination light is switched, and the second hue perceived by the observer before the illumination light is switched is perceived as having changed to the first hue perceived before the switch after the illumination light is switched," a configuration is described that finds an appropriate combination of material and illumination light and simulates the hues of the objects perceived by the observer for that combination.

[0016] A calculation unit 101 of the information processing device 100 shown in FIG. 1 acquires search conditions, calculates one or more candidate combinations of materials and illumination light that satisfy the search conditions and can be realized by the lighting device used in the lighting performance, and outputs to the outside the spectral reflectance of the materials perceived by the observer for each combination, and control information for each light source that emits illumination light and that constitutes the lighting device.

[0017] The search conditions include, for example, calculation conditions, the number of materials constituting the object, the hue perceived by the material when illuminated with illumination light, illumination light information, and adjustment parameters. The calculation conditions are conditions for the change in the hue of the material perceived by the observer due to switching of the illumination light. Examples of such conditions include "a certain hue perceived by the observer before switching of the illumination light is perceived as having changed to a different hue after switching of the illumination light" and "a first hue perceived by the observer before switching of the illumination light is perceived as having changed to a second hue perceived before switching after switching of the illumination light, and the second hue perceived by the observer before switching of the illumination light is perceived as having changed to the first hue perceived before switching after switching of the illumination light."

[0018] The illumination light information is information about the intensity of the illumination light emitted from each light source constituting the illumination device. The adjustment parameters are values ​​adjusted by the designer. The light source intensity control information is information that indicates a method for controlling the brightness of the illumination light emitted from each light source constituting the illumination device in order to realize the spectral distribution of the illumination light calculated as the above combination.

[0019] The illumination light output from the lighting device consists of light output from one type of light source or a combination of two or more types of light sources with different spectral distributions. By switching the illumination light irradiated onto one or more objects made of multiple materials with different spectral reflectances using the above-mentioned appropriate combination of material and illumination light from a first illumination light having a first spectral distribution to a second illumination light having a second spectral distribution different from the first spectral distribution, it is possible to achieve the following on the object surface: "a portion of the hue perceived by the observer before the illumination light is switched is perceived as having changed to a different hue after the illumination light is switched" or "the first hue perceived by the observer before the illumination light is switched is perceived as having changed to the second hue perceived before the switch after the illumination light is switched, and the second hue perceived by the observer before the illumination light is switched is perceived as having changed to the first hue perceived before the switch after the illumination light is switched."

[0020] (1) Calculation of candidate combinations of materials and illumination light Next, the function of the calculation unit 101 that realizes the central function of this embodiment will be described.

[0021] (Background theory) The reflectance spectrum from a point on the surface of an object illuminated by illumination light can be modeled as equation (1) using the spectral reflectance r(λ) at that point and the spectral distribution w(λ) of the illumination light, where λ represents the wavelength.

[0022]

[0023] Here, in formula (1), C t (λ) represents the color matching function defined by the International Commission on Illumination (CIE), which corresponds to the spectral sensitivity of the human eye, and v trepresent the colorimetric values ​​X, Y, and Z obtained by the dot product of the reflectance spectrum and each color matching function. When the perceived hue of an object is ideal white with perfect diffuse reflection, the spectral reflectance r(λ) takes a constant value at all wavelengths, and therefore equation (2) holds true.

[0024]

[0025] When an object is irradiated with illumination light from a first light source that emits illumination light having a spectral distribution of w1(λ), ​​if the hues of a first material with a spectral reflectance of r1(λ) and a second material with a spectral reflectance of r2(λ), which is different from r1(λ), ​​are perceived as the same hue by an observer, this can be mathematically expressed as equation (3) using equation (1).

[0026]

[0027] Since the human eye is sensitive to the wavelength range from 380 [nm] to 780 [nm], sampling the spectrum at 1 [nm] intervals results in 401-dimensional data. In this case, the color matching functions of X, Y, and Z are as shown in (a1) (hereinafter, the left side is C Ｘ , C Ｙ , C Ｚ (expressed as follows), expressing the spectral reflectance of the object as in (a2) and the spectral distribution of the illumination light as in (a3) ​​in a 401-dimensional matrix notation, and rewriting equation (3) as a determinant, yields equation (4). The variable in parentheses on the right side of equation (4) is the spectral reflectance at each wavelength, i.e., the ratio of the spectral reflectance intensity when 1 is the maximum. For example, when this variable is 380, it means the ratio of the intensity of the light actually being irradiated, divided by the maximum intensity of light with a wavelength of 380 [nm] that the illumination can irradiate.

[0028]

[0029] (Searching for a combination of material and illuminant spectral distribution that results in metamerism) Next, we will describe a method for finding a combination of material and illuminant spectral distribution that results in metamerism, based on the above background theory. In formulating this combination search, U() is defined as an operator that calculates the value in the color space of a given spectrum. Color spaces such as the "L*u*v* color space (CIE 1976)" or the "L*a*b* color space (CIE 1976)" are used. │|A - B│| is defined as the color difference between A and B in the color space. When using the above-mentioned L*u*v* color space, the color difference can also be defined as (a4). When using the above-mentioned L*a*b* color space, the color difference is calculated using the conventional Lab color difference distance formula or one of the formulas defined in standards such as "CIE DE 2000."

[0030]

[0031] Based on the above definitions, the calculation unit 101 searches for a combination of material and illumination light that matches the purpose for an object made of a material, based on the following formula (5) if "some hues perceived by the observer before the illumination light is switched are perceived as different hues after the illumination light is switched," and based on the following formula (6) if "a first hue perceived by the observer before the illumination light is switched is perceived as having changed to a second hue perceived before the switch, after the illumination light is switched, and the second hue perceived by the observer before the illumination light is switched is perceived as having changed to the first hue perceived before the switch, after the illumination light is switched."

[0032] (A) A part of the hue perceived by the observer before the change of illumination appears to have changed to a different hue after the change of illumination.

[0033]

[0034] (B) A first hue perceived by the observer before the illumination light is switched is perceived as having changed to a second hue perceived before the switching after the illumination light is switched, and the second hue perceived by the observer before the illumination light is perceived as having changed to a first hue perceived before the switching after the illumination light is switched.

[0035]

[0036] 2 is a diagram showing a first example of a change in the hue perceived by an observer of a material when the illumination light is switched. As shown in FIG. 2, the first spectral reflectance R １ The material, and (a6), R １ A second spectral reflectance R different from ２ For two types of materials, the spectral distribution w １ and a state in which the irradiated illumination light is switched from the first illumination light to the second illumination light having the spectral distribution w2 shown in (a8).

[0037]

[0038] When the condition (5) is satisfied with δ being close to 0, the spectral reflectance is R １ and a second material having a spectral reflectance R2, the illumination light having a spectral distribution w １ This shows that when the first illumination light with a spectral distribution of w is switched to the second illumination light with a spectral distribution of w2, the observer perceives that only the hue of the first material has changed, without the hue of the second material having changed.

[0039] In equation (5), if the brightness of white perceived by the observer does not change when the illumination light is switched, δ y = 0. δ and δ white is a value adjusted by the designer. δ takes a value of 0 or more, and the smaller δ is, the less the observer perceives the change in the hue of the second material when the illumination light is switched. When δ is close to 0, even if the illumination light is switched, the observer perceives the hue of the second material as being close to the hue before the switch. white The smaller the value of , the closer the way the observer sees white under the first illumination light to the way the observer sees white under the second illumination light.

[0040] Figure 3 shows a second example of a change in the hue perceived by an observer of a material when the illumination light is switched. The values ​​of the spectral distributions w1 and w2 shown in Figure 3 are different from the values ​​of the spectral distributions w1 and w2 shown in Figure 2. The same applies to Figures 4 and 5.

[0041] Equation (6) expresses R when, as shown in FIG. 3, the illumination light irradiating the first and second materials is switched from a first illumination light having a spectral distribution w1 to a second illumination light having a spectral distribution w2, the hue of the first material perceived under the first illumination light is perceived to have changed under the second illumination light to the hue of the second material perceived under the first illumination light, and the hue of the second material perceived under the first illumination light is perceived to have changed under the second illumination light to the hue of the first material perceived under the first illumination light. １ and R ２ And lol １ and w ２ This is a formula for finding combinations of

[0042] In equation (6), if the brightness of white perceived by the observer does not change when the illumination light is switched, δ y = 0. δ and δ white is a value adjusted by the designer. δ takes a value equal to or greater than 0, and the smaller δ is, the closer the hue of the first material under the first illumination light and the hue of the second material under the second illumination light are perceived by the observer, and the closer the hue of the second material under the first illumination light and the hue of the first material under the second illumination light are perceived. white The smaller the value of , the closer the way the observer sees white under the first illumination light to the way the observer sees white under the second illumination light.

[0043] In both equations (5) and (6), the first material (spectral reflectance: R1) and the second material (spectral reflectance: R ２ ), first illumination light (spectral distribution: w １ ), and the second illumination light (spectral distribution: w ２ ) may not have a single solution, but may have multiple solutions. In this case, each of the multiple solutions may be a combination that can be used for the performance. Also, the spectral reflectance R１ , the spectral reflectance R of the second material ２ , the spectral distribution of the first illumination light w １ , and the spectral distribution w of the second illumination light ２ Any of the above is R １ and R ２ And lol １ and w ２ The search conditions for determining the combination of may be fixed as shown in FIG. 6, which will be described later.

[0044] In addition, the spectral reflectance R １ , the spectral reflectance R of the second material ２ , the spectral distribution of the first illumination light w １ , and the spectral distribution w of the second illumination light ２ δ and δ are fixed values ​​or variable values ​​as search conditions. white Depending on the value of , there may be cases where no solution exists. When no solution exists, δ and δ white The value and search conditions are corrected and the calculation is performed again.

[0045] Here, the spectral distribution of the i-th illumination light w ｉ is modeled as a weighted linear sum of the spectral distributions of light sources with different spectral distributions. ｉ If the spectral distribution of the k-th illumination light is written as (a9) (hereinafter, e k ) and can be expressed by equation (7).

[0046]

[0047] In formula (7), α i,k represents the intensity parameter of each light source, and N represents the total number of light sources stored in the light source information storage unit 103. The spectral distribution w of the first illumination light １ is the sum of all the light sources indicated by the information stored in the light source information storage unit 103. １,k and the spectral distribution w of the second illumination light is determined by calculating ２ is the α for all individual light sources. ２,k It is determined by finding

[0048] Next, as an extension of equation (5), the calculation unit 101 calculates, using equation (5)', what spectral reflectance of a material should be selected and what spectral distribution of illumination light should be irradiated onto the material, for the purpose of "making the j hues perceived by the observer before the illumination light is switched perceive as different hues after the illumination light is switched, and making the M-j hues perceived by the observer before the illumination light is switched perceive as the same hues after the illumination light is switched." for an object made up of M materials with different spectral reflectances.

[0049] Furthermore, as an extension of equation (6), the calculation unit 101 calculates, using equation (6)', what spectral reflectances of materials should be selected and what spectral distribution of illumination light should be irradiated onto the materials, for the purpose of "making the observer perceive a first hue perceived by the observer before the illumination light is switched as having changed to a second hue perceived before the switch after the illumination light is switched, making the observer perceive the second hue perceived by the observer before the illumination light is switched as having changed to the first hue perceived before the switch after the illumination light is switched, and making the observer perceive hues other than the first and second hues perceived by the observer before the illumination light is switched, i.e., M-2 hues, as the same hues even after the illumination light is switched."

[0050] (A') j hues perceived by the observer before the illumination light is switched are perceived as different hues after the illumination light is switched, and M-j hues perceived by the observer before the illumination light is switched are perceived as the same hues after the illumination light is switched.

[0051]

[0052] (C) The first hue perceived by the observer before the illumination light is switched is perceived as having changed to the second hue perceived before the switching after the illumination light is switched, the second hue perceived by the observer before the illumination light is switched and the second hue perceived by the observer before the illumination light is switched is perceived as having changed to the first hue perceived before the switching after the illumination light is switched, and hues other than the first and second hues perceived by the observer before the illumination light is switched, i.e., M-2 hues, are perceived as the same hues even after the illumination light is switched.

[0053]

[0054] 4 is a diagram showing a third example of a change in the hue perceived by an observer of a material when the illumination light is switched. As shown in FIG. 4, the formula (5)′ is expressed as (a10) when the spectral reflectance is R １ , ...R ｊ , R ｊ＋１ …R Ｍ For the material group, the spectral distribution w １ and the state in which the material group is irradiated with the first illumination light having the spectral distribution w ２ 10 shows a state in which the illumination light is switched to a second illumination light having a value of .gtoreq..times ...

[0055]

[0056] When this formula (5)' is satisfied under the condition that δ is close to 0, the spectral reflectance is R １ , ..., R ｊ The illumination light irradiated onto the material group (0<j<M) is expressed as a spectral distribution of w １ The spectral distribution of the first illumination light is w ２ When the light source is switched to the second illumination light, the observer perceives the hue of the material as changing, and the spectral reflectance of the material changes. ｊ＋１ , ..., R Ｍ This indicates that for the material group where the hue is perceived as not changing even when the irradiated illumination light is switched from the first illumination light to the second illumination light.

[0057] In the formula (5)', when the brightness of the white color perceived by the observer does not change when the illumination light is switched, δ y = 0. δ and δ white is a value adjusted by the designer. δ takes a value of 0 or more, and the smaller δ is, the more the observer perceives the spectral reflectance as R ｊ＋１ , ..., R Ｍ In the material group where δ is the hue perceived as close to the same hue even when the irradiated illumination light is switched from the first illumination light to the second illumination light. whiteThe smaller the value of , the closer the appearance of white to the observer under the first illumination light is to the appearance of white to the observer under the second illumination light. When j = 1 and M = 2, equation (5)' is the same as equation (5).

[0058] 5 is a diagram showing a fourth example of a change in the hue perceived by an observer of a material when the illumination light is switched. As shown in FIG. 5, the equation (6)′ is expressed as (a11) when the spectral reflectance is R １ , R ２ , ..., R Ｍ For the material group, the spectral distribution w １ and the state in which the first illumination light having the spectral distribution w ２ 10 shows a state in which the illumination light is switched to a second illumination light having a value of .gtoreq..times ...

[0059]

[0060] When this formula (6)' is satisfied under the condition that δ is close to 0, the spectral reflectance is R １ , R ２ , ..., R Ｍ The illumination light irradiated onto the material group is １ The spectral distribution of the first illumination light is w ２ When the light source is switched to the second illumination light, the observer can see that the spectral reflectance before the switch is R １ The perceived hue of the material is the spectral reflectance information R before switching. ２ The perceived hue of the material is perceived as having changed to R ２ The perceived hue of the material is the spectral reflectance information R before switching. １ The perceived hue of the material is changed, and the spectral reflectance is R ３ , ..., R Ｍ This indicates that the hue of the material is perceived as not changing even when the lighting is switched.

[0061] In the formula (6)', when the brightness of the white color perceived by the observer does not change when the illumination light is switched, δ y = 0. δ and δ whiteis a value adjusted by the designer. δ takes a value equal to or greater than 0, and the smaller δ is, the more the observer perceives the spectral reflectance under the first illumination light as R １ The perceived hue of the material and the spectral reflectance under the second illumination light are ２ The perceived hue of the material is closer to that of the material with the spectral reflectance R ２ The perceived hue of the material and the spectral reflectance under the second illumination light are １ The variable that the perceived hue of the material approaches is δ. white The smaller the value of , the closer the way the observer sees white under the first illumination light to the way the observer sees white under the second illumination light.

[0062] In both formulas (5)' and (6)', the material group (spectral reflectance: R １ , ..., R Ｍ ), and the first illumination light (spectral distribution: w １ ), and the second illumination light (spectral distribution: w ２ ) may not have a single solution, but may have multiple solutions. In this case, each of the multiple solutions may be a combination that can be used for the performance. Also, the spectral reflectance R １ , ..., R Ｍ , the spectral distribution of the first illumination light w １ , and the spectral distribution w of the second illumination light ２ Any of the above can be used as the R １ , R ２ , ..., R Ｍ And lol １ and w ２ The spectral reflectance R １ , ..., R Ｍ , the spectral distribution of the first illumination light w １ , and the spectral distribution w of the second illumination light ２ Among these, fixed values ​​as search conditions or variable values ​​δ and δ white Depending on the value of , there may be cases where no solution exists. When no solution exists, δ and δ white The value and search conditions are corrected and the calculation is performed again.

[0063] Here, the spectral distribution w of the i-th illumination light １ can be similarly calculated using equation (7) in equations (5)' and (6)'. In addition, in any of equations (5), (6), (5)', and (6)', the value indicated by (a12) can be removed from the corresponding equation, thereby eliminating the constraint that the hue of a material perceived under an illumination light used to change the perceived hue of the material must be natural white.

[0064]

[0065] (2) Next, the spectral distribution of light emitted from each light source will be described. The light source information storage unit 103 stores the spectral distribution of light emitted from each of the N light sources (hereinafter referred to as e １ , e ２ , ..., e Ｎ The value indicated by (a14) is, for example, the spectral distribution of light emitted from a monochromatic LED light source, and is expressed as the light intensity indicated by (a15) in each wavelength range when the wavelength range from 380 [nm] to 780 [nm] is split in 1 [nm] increments.

[0066]

[0067] (3) Next, the color matching function will be described. The color matching function storage unit 104 has a storage area for storing the color matching function. This color matching function is, for example, the color matching function C Ｘ , C Ｙ , C Ｚ is a color matching function of the colorimetric values ​​X, Y, and Z coordinates, it is expressed as a matrix data of the tristimulus intensity for a 2-degree visual field, with the wavelength range from 380 nm to 780 nm divided in 1 nm increments.

[0068] (4) Search Condition Input The input unit 106 accepts input of search conditions. The search conditions include a calculation condition specifying an applicable calculation formula such as formula (5) or (5)', a number of hues corresponding to the number of types of materials with different spectral reflectances to be irradiated with illumination light, material information specifying the spectral reflectance of the materials for each wavelength, illumination light information specifying the spectral distribution of illumination light irradiated from each light source, and δ and δ whiteThe adjustment parameter information includes:

[0069] Next, based on the above explanation, the processing of each unit of the information processing device 100 shown in Fig. 1 will be described. The input unit 106 accepts input of search conditions. Examples of the search conditions include calculation conditions, the number of hues, material information, illumination light information, δ parameters, and δ white The parameters include:

[0070] FIG. 6 is a diagram showing an example of search conditions in a table format. The calculation condition can be one of three conditions: specific color change ( FIG. 6( a)), color exchange ( FIG. 6( b)), and specific color exchange (c). The specific color change indicates that "j hues perceived by the observer before switching the illumination are perceived as different hues after switching the illumination, and M-j hues perceived by the observer before switching the illumination remain the same after switching the illumination." The color exchange indicates that "a first hue perceived by the observer before switching the illumination is perceived as having changed to a second hue perceived before switching the illumination, and the second hue perceived by the observer before switching the illumination is perceived as having changed to the first hue perceived before switching the illumination." The above-mentioned specific color exchange indicates that "a first hue perceived by the observer before the illumination light is switched is perceived as having changed to a second hue perceived before the switch after the illumination light is switched, and the second hue perceived by the observer before the illumination light is switched and the second hue perceived by the observer before the illumination light is switched are perceived as having changed to the first hue perceived before the switch after the illumination light is switched, and hues other than the first and second hues perceived by the observer before the illumination light is switched, i.e., M-2 hues, are perceived as the same hues even after the illumination light is switched."

[0071] The above-mentioned number of hues is an integer of 2 or greater when the calculation condition is a specific color change, 2 when the calculation condition is a color exchange, and an integer of 3 or greater when the calculation condition is a specific color exchange. Furthermore, when the calculation condition is a specific color change, the number of changed colors can be specified as a search condition in addition to the number of hues, as shown in Figure 6(a). This number of changed colors is the number of hues that an observer perceives as having changed due to the switching of illumination light, and is an integer greater than or equal to 1 and smaller than the number of hues.

[0072] Fig. 7 is a diagram showing an example of material information of a search condition in table form. The material information shown in Fig. 7 is matrix data representing spectral reflectance information of materials for each wavelength, and is stored in the spectral reflectance storage unit 105. This material information need not be set as a search condition, or may be set as a matrix corresponding to a number of hues equal to or less than the number of hues shown in Fig. 7. For example, if there are hues to be included in a specific lighting performance target, the material information can be obtained by measuring the target with a spectrometer or the like.

[0073] 8 is a diagram showing an example of illumination light information of a search condition in a table format. The illumination light information shown in FIG. 8 is data indicating illumination intensity for each light source number, which is a unique number assigned to each light source. When there are N light sources, the ... ｉ (i = 1, 2)" and "A ｉ = {a ｉ，１ , a ｉ，２ , ..., a ｉ，ｋ , ..., a ｉ，Ｎ}". This illumination light information does not need to be set at all, and the above-mentioned "A ｉ (i=1, 2)" or both may be set. The number of light sources is assumed to be the same as the number of light sources indicated by the spectral distribution of light emitted from each light source, which is stored in the light source information storage unit 103, or the number of light sources constituting the lighting device.

[0074] 9 is a diagram showing an example of spectral distribution data of light intensity of each light source in a table format. In this embodiment, the spectral distribution of light emitted from each light source stored in the light source information storage unit 103 is information in which the spectral distribution data of light intensity is represented as matrix data for each light source, as shown in FIG. 9. In FIG. 9, when there are N light sources, matrix data e representing the spectral distribution data of individual illumination numbers "1" to "N" is used. １ , e ２ , ..., e Ｎ is recorded in the light source information storage unit 103.

[0075] The color matching functions stored in the color matching function storage unit 104 are color matching functions C that correspond to the intensities of the tristimulus values ​​at each wavelength of the "CIE XYZ color matching functions (1931)" and the XYZ coordinates. Ｘ , C Ｙ , C Ｚ It consists of matrix data.

[0076] Fig. 10 is a diagram showing an example of color matching function data in a table format. As shown in Fig. 10, color matching function data for each wavelength is stored in the color matching function storage unit 104. It is assumed that the material information shown in Fig. 7, the spectral distribution data shown in Fig. 9, and the color matching functions shown in Fig. 10 all have the same spectral width of 4 [nm] for each wavelength.

[0077] 11 is a flowchart showing an example of a processing operation by the calculation unit 101. The calculation unit 101 reads the search conditions as shown in FIG. 6, which are input via the input unit 106 (S101-1), and further refers to information on the spectral distribution of illumination light from each light source stored in the light source information storage unit 103 and information on color matching functions stored in the color matching function storage unit 104 (S101-2).

[0078] Next, the calculation unit 101 calculates candidate combinations of materials and illumination light that match the search conditions based on the received search conditions and the information referenced in S101-2 (S101-3). １ = {a １，１ , a １，２ , ..., a １，ｋ , ..., a １，Ｎ}" is included, the calculation unit 101 determines w as a fixed value based on the formula (7). １ Calculate the above search condition. ２ = {a ２，１ , a ２，２ , ..., a ２，ｋ , ..., a ２，Ｎ}" is included, the calculation unit 101 determines w as a fixed value based on the formula (7). ２ Calculate the above search conditions. １ and A ２ When both of these are included, the calculation unit 101 determines w as a fixed value based on the formula (7). １ and w ２ Calculate both.

[0079] In step S101-3, when the calculation condition in the search condition is the specific color change shown in FIG. 6A, the calculation unit 101 calculates R that satisfies the formula (5)'. １ , ...R ｊ , R ｊ＋１ …R Ｍ And, lol １ and w ２ In this way, when the calculation condition is a specific color change, the number of changed colors is j and the number of hues is M in the calculation condition.

[0080] In addition, in S101-3, when the calculation condition in the search condition is the color exchange shown in FIG. 6B, the calculation unit 101 calculates R １ and R ２ And, lol １ and w ２ Find a combination with.

[0081] Furthermore, in S101-3, when the calculation condition in the search condition is the specific color exchange shown in FIG. 6C, the calculation unit 101 calculates R １ , R ２ , ..., R Ｍ And, lol １ and w ２ In this way, when the calculation condition is a specific color exchange, the number of hues in the search condition is M. Also, in all the calculation conditions described above, δ and δ whiteThe parameter values ​​given in the search condition input are used.

[0082] In the calculation of the material information and the illumination light information that satisfies the formula (5)', (6), or (6'), R included as material information in the search conditions is １ , R ２ , ..., R Ｍ and the w obtained from the illumination light information of the search conditions １ , or w ２ , or w １ and w ２ Both are treated as constants.

[0083] Then, for material information or illumination light information that is not treated as a constant, the calculation unit 101 searches for a value that satisfies formula (5)', (6), or (6)'. In this search, the material information is searched for within a region in which each element of the spectral reflectance at each wavelength takes an arbitrary value from 0 to 1, and the illumination light information is searched for within a region in which each element takes an arbitrary value from 0 to 1. ｉ = {a ｉ，１ , a ｉ，２ , ..., a ｉ，ｋ , ..., a ｉ，Ｎ}", each element is searched within a range of values ​​between 0 and 1.

[0084] Based on the results of this search, once the calculation unit 101 has calculated a combination of material information and illumination light information that satisfies formula (5)', (6), or (6)', the calculation unit 101 advances the process to S101-4.

[0085] In S101-4, the calculation unit 101 checks the number of combinations of material information and illumination light information found in S101-3 (S101-4), and if the number of combinations is less than one (NO in S101-4), it concludes that there is no solution under the given search conditions and ends the series of processes.On the other hand, if the number of combinations is one or more (YES in S101-4), the calculation unit 101 proceeds to S101-5.

[0086] Next, the calculation unit 101 checks the number of combinations of material information and illumination light information calculated in S101-3 (S101-5), and if this number of combinations is two or more (YES in S101-5), the calculation unit 101 proceeds to S101-6. On the other hand, if the number of combinations is not two or more, that is, if the number of combinations is one (NO in S101-5), the calculation unit 101 proceeds to S101-7.

[0087] In S101-6, the calculation unit 101 selects one of the calculated combinations of material information and illumination light information, and proceeds to S101-7. For this selection, the calculation unit 101 can select the term with the smallest average among the terms in equation (5)', (6), or (6)' that are constrained to be equal to or less than δ, or can select the term with the smallest average among the terms in equation (5)', (6), or (6)' that are constrained to be equal to or less than δ. white You can either choose the smallest term that is constrained to be less than or equal to, or you can choose a set at random.

[0088] In S101-7, the calculation unit 101 outputs material information from one combination of material information and illumination light information selected as described above. The material information can be displayed on a monitor (not shown) or can be written externally as a text file. This written material information is the same matrix data as the matrix data shown in FIG. 7. In S101-7, the matrix data given as material information in the search conditions is output as is.

[0089] After the process of S101-7, the calculation unit 101 outputs the illumination light information from one of the combinations of material information and illumination light information selected as described above (S101-8). This output illumination light information is calculated based on the formula (7) and the spectral distribution e of the light emitted from each light source. １ , e ２ , ..., e Ｎ Based on the spectral distribution w １ and w ２ "A" is necessary to create an illumination light having １ = {a １，１ , a １，２ , ..., a １，ｋ , ..., a １，Ｎ}" and "A２ = {a ２，１ , a ２，２ , ..., a ２，ｋ , ..., a ２，Ｎ}". In S101-8, the calculation unit 101 outputs the matrix data given as the illumination light information in the search conditions as it is.

[0090] In the above-described S101-8, the calculation unit 101 can display the illumination light information on a monitor in the same way as the material information, or can write it out externally as a text file. When the process of S101-8 is completed, the calculation unit 101 ends the series of processes.

[0091] Fig. 12 is a diagram showing a second application example of an information processing device according to an embodiment of the present invention. In the example shown in Fig. 12, the information processing device 100a further includes an illumination control unit 102 in addition to the components of the information processing device 100 shown in Fig. 1. The illumination control unit 102 controls the intensity of illumination light emitted from each light source constituting the illumination device 200 for each light source. The illumination device 200 is constructed by combining N individual light sources.

[0092] In S101-7, the calculation unit 101 of the information processing device 100a outputs to the outside the material information of one combination of material information and illumination light information selected as described above, and also transmits the illumination light information of this combination to the illumination control unit 102.

[0093] FIG. 13 is a flowchart showing an example of the processing operation of the illumination control unit. First, the illumination control unit 102 receives illumination light information transmitted from the calculation unit 101 (S102-1). Here, the received illumination light information is １ = {a １，１ , a １，２ , ..., a １，ｋ , ..., a １，Ｎ}" and "A ２ = {a ２，１ , a ２，２ , ..., a ２，ｋ , ..., a ２，Ｎ}".

[0094] Next, the illumination control unit 102 selects the first illumination light information from the illumination light information received in S102-1, that is, the illumination light information “A １ = {a １，１ , a １，２ , ..., a １，ｋ , ..., a １，Ｎ}," the lighting device 200, which is configured by combining a plurality of light sources, is controlled (S102-2).

[0095] The spectral distribution of each illumination is stored in the light source information storage unit 103. １ , e ２ , ..., e Ｎ The spectral distribution of the light output from the lighting device 200 as illumination light is the same as that of "A ｉ = {a ｉ，１ , a ｉ，２ , ..., a ｉ，ｋ , ..., a ｉ，Ｎ}" is input as control data, the w ｉ When the illumination device 200 irradiates the object with illumination light under the control of the illumination device 200, the illumination control unit 102 waits for a certain period of time before proceeding to step S102-3.

[0096] In S102-3, the illumination control unit 102 receives the second illumination light information from the illumination light information received in S102-1, that is, the illumination light information “A ２ = {a ２，１ , a ２，２ , ..., a ２，ｋ , ..., a ２，Ｎ}" and controls the lighting device 200. When the lighting device 200 irradiates the object with illumination light through this control, the lighting control unit 102 waits for a certain period of time before completing the series of processes.

[0097] In this embodiment, illumination light is irradiated onto an object made up of a plurality of materials with different spectral reflectances, which are prepared based on the material information output from the calculation unit 101, and when this irradiated illumination light having a first spectral distribution is switched to illumination light having a second spectral distribution, an effect can be realized in which "some hues perceived by the observer before the illumination light is switched are perceived as having changed to different hues after the illumination light is switched" or "the first hue perceived by the observer before the illumination light is switched is perceived as having changed to the second hue perceived before the switch after the illumination light is switched, and the second hue perceived by the observer before the illumination light is switched is perceived as having changed to the first hue perceived before the switch after the illumination light is switched."

[0098] Here, an object made up of a plurality of materials is an object made up of a plurality of materials having the same spectral reflectance as the spectral reflectance of the plurality of materials indicated in the material information output by the calculation unit 101 .

[0099] Fig. 14 is a block diagram showing an example of the hardware configuration of an information processing device according to an embodiment of the present invention. In the example shown in Fig. 14, the information processing device 100 according to the embodiment is configured, for example, by a server computer or a personal computer, and has a hardware processor 111A such as a CPU (Central Processing Unit). A program memory 111B, a data memory 112, an input / output interface 113, and a communication interface 114 are connected to this hardware processor 111A via a bus 115. The same applies to the information processing device 100a shown in Fig. 12.

[0100] The communication interface 114 includes, for example, one or more wireless communication interface units, and enables transmission and reception of information to and from a communication network. As the wireless interface, for example, an interface that adopts a low-power wireless data communication standard such as a wireless LAN (Local Area Network) is used.

[0101] An input device 500 and an output device 600, which are attached to the information processing device 100 and used by a user or the like, are connected to the input / output interface 113. The input / output interface 113 can take in operation data input by a user or the like through the input device 500, such as a keyboard, a touch panel, or a touchpad, and can output and display output data to an output device 600, which includes a display device using a liquid crystal or an organic electroluminescence (EL) display or the like. The input device 500 and the output device 600 may be devices built into the information processing device 100, or may be input devices and output devices of other information terminals that can communicate with the information processing device 100 via a network.

[0102] The program memory 111B is a non-transitory tangible storage medium that is a combination of a non-volatile memory that can be written to and read from at any time, such as a hard disk drive (HDD) or a solid state drive (SSD), and a non-volatile memory such as a read only memory (ROM), and can store programs necessary to execute various control processes, etc., according to one embodiment.

[0103] The data memory 112 is a tangible storage medium that is, for example, a combination of the above-mentioned nonvolatile memory and a volatile memory such as RAM (Random Access Memory), and can be used to store various data or information acquired and created during various processes.

[0104] An information processing apparatus 100 according to one embodiment of the present invention can be configured as an information processing apparatus having the units shown in FIG. 1 as software-based processing function units.

[0105] The information storage unit used as a work memory or the like by each unit of the information processing device 100 can be configured by using the data memory 112 shown in Fig. 14. However, these configured storage areas are not essential components within the information processing device 100, and may be areas provided in an external storage medium such as a USB (Universal Serial Bus) memory, or a storage device such as a database server located in the cloud.

[0106] The processing function units in each of the above units can be realized by reading and executing a program stored in the program memory 111B by the hardware processor 111A. Note that some or all of these processing function units may be realized in various other forms, including integrated circuits such as an application specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).

[0107] The methods described in each embodiment can be stored as a program (software means) that can be executed by a computer on a recording medium such as a magnetic disk (floppy disk, hard disk, etc.), optical disk (CD-ROM, DVD, MO, etc.), or semiconductor memory (ROM, RAM, flash memory, etc.), and can also be distributed by transmitting it via a communication medium. The program stored on the medium also includes a configuration program that configures the software means (including not only execution programs but also tables or data structures) that the computer executes. The computer that realizes this device reads the program stored on the recording medium and, in some cases, configures the software means using the configuration program, and executes the above-mentioned processing by controlling the operation of this software means. The term "recording medium" as used herein is not limited to a storage medium for distribution, but also includes a storage medium such as a magnetic disk or semiconductor memory installed inside the computer or in a device connected via a network.

[0108] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0109] REFERENCE SIGNS LIST 100, 100a... Information processing device 101... Calculation unit 102... Lighting control unit 103... Light source information storage unit 104... Color matching function storage unit 105... Spectral reflectance storage unit 106... Input unit 200... Lighting device

Claims

1. An information processing device comprising: a calculation unit that calculates combinations of materials constituting an object and illumination light such that, when illumination light from a lighting device constituted by a combination of light sources emitting light having a first spectral distribution is irradiated onto a single or multiple objects made of multiple materials with different spectral reflectances, multiple hues are perceived by an observer, and when illumination light from a lighting device constituted by a combination of light sources emitting light having a second spectral distribution different from the first spectral distribution is irradiated onto the object instead, some of the multiple hues are perceived by the observer as different hues, based on the spectral reflectances of the materials, the spectral distribution of the illumination light, and color matching functions corresponding to the spectral sensitivity of the human eye.

2. The information processing device of claim 1, wherein the calculation unit calculates a combination of the material and the illumination light based on the spectral reflectance of the material and the spectral distribution of the illumination light so that when the hue perceived by the observer includes white, the white appears appropriate to the observer.

3. The information processing device according to claim 1, further comprising a control unit that controls the intensity of the illumination light irradiated from the illumination device onto the object based on the result of the calculation by the calculation unit.

4. A method performed by an information processing device, comprising: a calculation unit of the information processing device calculating, based on the spectral reflectance of the materials, the spectral distribution of the illumination light, and color matching functions corresponding to the spectral sensitivity of the human eye, combinations of materials constituting the object and illumination light such that, when illumination light from an illumination device constituted by a combination of light sources emitting light having a first spectral distribution is irradiated onto a single or multiple objects made of multiple materials with different spectral reflectances, multiple hues are perceived by an observer, and when illumination light from an illumination device constituted by a combination of light sources emitting light having a second spectral distribution different from the first spectral distribution is irradiated onto the object instead of this irradiation, some of the multiple hues are perceived by the observer as different hues.

5. An information processing program that causes a processor to function as each part of the information processing device according to any one of claims 1 to 3.

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