Evaluation method and system for evaluating spectrum similarity of light sources with different color temperatures

Abstract

The invention discloses an evaluation method and system for evaluating spectrum similarity of light sources with different color temperatures, and relates to the field of spectrum similarity, and the method comprises the steps: obtaining power spectrums of two colored light sources to be evaluated; according to the power spectrum, determining a light-emitting brightness spectrum of each colored light source; judging whether the color temperatures of the two colored light sources are the same or not, and if the color temperatures are the same, calculating the similarity of the two colored light sources according to a natural spectrum similarity index formula; and if the color temperatures are different, calculating the similarity of the two colored light sources according to a spectrum similarity index formula considering the color temperatures. According to the method, the calculation accuracy of spectrum similarity analysis can be effectively improved, the result consistency is enhanced, a more accurate spectrum analysis tool is provided for various fields related to color temperature change, and development and innovation of related technologies are promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of spectral similarity, and more particularly to an evaluation method and system for evaluating the spectral similarity of light sources with different color temperatures. Background Art

[0002] The Natural Spectrum Similarity Index (SRI) is an indicator that measures the similarity between a lighting source and the spectrum of natural light. It is a quantitative value obtained by comparing the spectral distribution of the light source to be tested with the spectral distribution of natural light at the same color temperature, and taking into account the sensitivity of the human eye to light of different wavelengths. The index aims to provide users with a more comfortable and healthier lighting environment, while helping lighting source designers better understand the spectral quality of the light source.

[0003] The natural spectrum similarity index is to weight the brightness function of the energy spectrum of the light source to be tested and the black body radiation at the same color temperature, and compare the weighted brightness spectrum to obtain a quantitative value to characterize the similarity between the two. However, this calculation process ignores the crucial parameter of color temperature. In practical applications, as the color temperature increases, it is found that the similarity increases, but the actual observation by the naked eye is not similar, that is, the spectrum similarity index shows an unexpected upward trend, while at the same time the naked eye can clearly identify the significant differences between the spectra.

[0004] Therefore, how to improve the accuracy and reliability of the spectral similarity analysis between the light source to be tested and the natural light is a problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] In view of this, the present invention provides a method and system for evaluating the spectral similarity of light sources with different color temperatures, which solves the dilemma that the calculation results of the spectral similarity index are significantly inconsistent with the actual observation results due to the increase in color temperature, thereby improving the accuracy and reliability in complex spectral analysis.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention discloses an evaluation method for evaluating the spectral similarity of light sources with different color temperatures, and the specific steps are as follows:

[0008] Step 1: Obtain the power spectra of two colored light sources to be evaluated;

[0009] Step 2: Determine the luminous brightness spectrum of each of the colored light sources according to the power spectrum;

[0010] Step 3: Determine whether the color temperatures of the two colored light sources are the same. If the color temperatures are the same, calculate the similarity of the two colored light sources according to the natural spectrum similarity index formula; if the color temperatures are different, calculate the similarity of the two colored light sources according to the spectrum similarity index formula considering the color temperature.

[0011] Furthermore, the step 1 includes: placing the two colored light sources to be evaluated in a dark room, measuring the light intensity of each wavelength band of each colored light source by a photometer, and determining the power spectrum of each colored light source.

[0012] Furthermore, the step 2 comprises:

[0013] Integrating the power spectrum with the human eye viewing function to obtain the luminous flux of each wavelength band of each of the colored light sources;

[0014] Determine a photometric function between the radiation power of the colored light source and the luminous flux according to the luminous flux;

[0015] The power spectrum is multiplied by the luminosity function to obtain the luminous brightness spectrum.

[0016] Furthermore, the calculation formula of the luminous brightness spectrum is:

[0017] L i (λ,T)=I i (λ,T)×V(λ,T);

[0018] Among them, I i (λ,T) represents the power spectrum of the i-th colored light source, V(λ,T) represents the luminosity function, L i (λ,T) represents the luminous brightness spectrum of the i-th colored light source; λ represents the wavelength, and T represents the color temperature.

[0019] Furthermore, the natural spectrum similarity index formula is:

[0020]

[0021] Among them, SRI represents the natural spectrum similarity index, L(λ,T) represents the overlapping area between the luminous brightness spectrum and the blackbody radiation, and L BR (λ,T) represents the brightness spectrum of blackbody radiation.

[0022] Furthermore, the spectral similarity index formula considering color temperature is:

[0023]

[0024] Among them, SRI CCT Indicates the spectral similarity index considering color temperature, CCT1 indicates the color temperature of the comparison light source, and CCT2 indicates the color temperature of the target light source.

[0025] The present invention also discloses an evaluation system for evaluating the similarity of spectra of light sources with different color temperatures, comprising:

[0026] Power spectrum module: obtains the power spectra of the two colored light sources to be evaluated;

[0027] Luminous brightness spectrum module: determining the luminous brightness spectrum of each of the colored light sources according to the power spectrum;

[0028] Similarity calculation module: determines whether the color temperatures of the two colored light sources are the same. If the color temperatures are the same, the similarity of the two colored light sources is calculated according to the natural spectrum similarity index formula; if the color temperatures are different, the similarity of the two colored light sources is calculated according to the spectrum similarity index formula considering the color temperature.

[0029] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses an evaluation method and system for evaluating the spectral similarity of light sources with different color temperatures, which has the following technical effects: By incorporating the color temperature factor, the present invention can more comprehensively reflect the true characteristics of spectral data, reduce the calculation errors caused by color temperature changes, and thus significantly improve the calculation accuracy of the spectral similarity index. In a variety of actual scenarios of color temperature changes, the conclusions obtained by the present invention will be closer to the results of naked eye observations, effectively avoiding obvious inconsistencies that may occur in the existing evaluation system, and enhancing the consistency, practicality and credibility of the results. The present invention is applicable to more fields involving color temperature changes, such as lighting engineering, color science, remote sensing monitoring, etc., providing more accurate spectral analysis tools for these fields and promoting the development and innovation of related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0031] Figure 1 It is a schematic diagram of the overall process of an embodiment of the present invention.

[0032] Figure 2 Schematic diagram of calculating the spectral similarity between the D4 device and candlelight according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The embodiment of the present invention discloses a method for evaluating the similarity of spectra of light sources with different color temperatures. Figure 1 As shown, the specific steps are as follows:

[0035] Step 1: Obtain the power spectra of two colored light sources to be evaluated;

[0036] Step 2: Determine the luminous brightness spectrum of each colored light source according to the power spectrum;

[0037] Step 3: Determine whether the color temperatures of the two colored light sources are the same. If the color temperatures are the same, calculate the similarity of the two colored light sources according to the natural spectrum similarity index formula; if the color temperatures are different, calculate the similarity of the two colored light sources according to the spectrum similarity index formula considering the color temperature.

[0038] In a specific embodiment, step 1 includes: placing two colored light sources to be evaluated in a dark room, measuring the light intensity of each wavelength band of each colored light source by a photometer, and determining the power spectrum of each colored light source.

[0039] In a specific embodiment, step 2 includes:

[0040] Integrate the power spectrum with the human eye's visual function to obtain the luminous flux of each band of each colored light source;

[0041] Determine the photometric function between the radiant power of the colored light source and the luminous flux according to the luminous flux;

[0042] The power spectrum is multiplied by the luminosity function to obtain the luminous brightness spectrum.

[0043] Specifically, the human eye viewing function is determined by the Commission Internationale de L'Eclairage (CIE), a non-profit international standardization organization, based on a large number of observations. CIE has conducted a large number of observations and experiments on the visual perception of many people, and determined the average relative sensitivity of the human eye to light of various wavelengths by the average method. This sensitivity is called the spectral luminous efficiency of the "standard photometric observer", also known as the human eye viewing function. This is one of the basic standards formulated and promoted by CIE in the field of lighting, which is used to describe and quantify the sensitivity of the human eye to light of different wavelengths. By setting a standardized human eye viewing function, people can more easily match and compare colors, which is of great significance in color measurement, color management, and color coordination. Moreover, the human eye viewing function can quantify the sensitivity of the human eye to light of different wavelengths, thereby revealing which wavelengths of light are easier for the human eye to perceive and recognize. This reveals the visual characteristics of the human eye and has guiding significance for the development of optical research.

[0044] The luminous flux is obtained by integrating the power spectrum with the human eye's visual function. The luminous flux is a physical quantity that describes the degree of visual stimulation of the visible light radiated by the light source to the human eye. It reflects the part of the radiant energy of the light source in the visible light range that is perceived by the human eye. From this, the luminosity function can be derived, which refers to the function of the relationship between the radiant power of the light source and the luminous flux. The luminosity function can be used to describe the luminous efficiency of the light source, that is, the luminous flux that can be generated by unit radiant power. Then the power spectrum is multiplied by the luminosity function to obtain the luminous brightness spectrum. However, the spectral similarity index calculated in this way is affected by error factors, so the color temperature indicator is introduced for revision.

[0045] In a specific embodiment, the calculation formula of the luminous brightness spectrum is:

[0046] L i (λ,T)=I i (λ,T)×V(λ,T);

[0047] Among them, I i (λ,T) represents the power spectrum of the i-th colored light source, V(λ,T) represents the luminosity function, L i (λ,T) represents the luminous brightness spectrum of the i-th colored light source; λ represents the wavelength, and T represents the color temperature.

[0048] In a specific embodiment, the natural spectrum similarity index formula is:

[0049]

[0050] Among them, SRI represents the natural spectrum similarity index, L(λ,T) represents the overlapping area between the luminous brightness spectrum and the blackbody radiation, and L BR (λ,T) represents the brightness spectrum of blackbody radiation.

[0051] In a specific embodiment, the spectral similarity index formula considering the color temperature is:

[0052]

[0053] Among them, SRI CCT Indicates the spectral similarity index considering color temperature, CCT1 indicates the color temperature of the comparison light source, and CCT2 indicates the color temperature of the target light source.

[0054] In a specific embodiment, the spectra of three different light source devices are compared with candlelight.

[0055] Option 1: Select the B3 device and compare it with the spectrum of candlelight.

[0056] The color temperature of the light source of the B3 device is 1850K, and the color rendering index is 91.7Ra; the color temperature of the light source of the candlelight is 1853K, and the color rendering index is 99.8Ra. i The brightness spectrum L is obtained by multiplying (λ,T) with the luminosity function V(λ,T) i (λ,T), and then integrate the two light sources separately, introducing the formula The spectral similarity index can be calculated to be 75.48%.

[0057] Under the newly established spectral similarity index system, the power spectrum I i The brightness spectrum L is obtained by multiplying (λ,T) with the luminosity function V(λ,T) i (λ,T), and then integrate the two light sources separately, and then consider the influence of color temperature and introduce the formula The spectral similarity index can be calculated to be 75.36%.

[0058] Option 2: Choose the C2 device and compare it with the spectrum of candlelight.

[0059] The color temperature of the light source of the C2 device is 1734K, and the color rendering index is 90.6Ra; the color temperature of the light source of the candlelight is 1853K, and the color rendering index is 99.8Ra. Under Jou's natural spectrum similarity index system, the power spectrum I i The brightness spectrum L is obtained by multiplying (λ,T) with the luminosity function V(λ,T) i (λ,T), and then integrate the two light sources separately, introducing the formula The spectral similarity index can be calculated to be 70.88%.

[0060] Under the newly established spectral similarity index system, the power spectrum I i The brightness spectrum L is obtained by multiplying (λ,T) with the luminosity function V(λ,T) i (λ,T), and then integrate the two light sources separately, and then consider the influence of color temperature and introduce the formula The spectral similarity index can be calculated to be 66.33%.

[0061] Solution 3: Select the spectrum of the D4 device and candlelight for comparison, such as Figure 2 shown.

[0062] The color temperature of the light source of the D4 device is 1654K, and the color rendering index is 91.1Ra; the color temperature of the light source of candlelight is 1853K, and the color rendering index is 99.8Ra. Under Jou's natural spectrum similarity index system, the power spectrum I i The brightness spectrum L is obtained by multiplying (λ,T) with the luminosity function V(λ,T) i(λ,T), and then integrate the two light sources separately, introducing the formula The spectral similarity index can be calculated to be 67.81%.

[0063] Under the newly established spectral similarity index system, Figure 2 As shown, the power spectrum I i The brightness spectrum L is obtained by multiplying (λ,T) with the luminosity function V(λ,T) i (λ,T), and then integrate the two light sources separately, and then consider the influence of color temperature and introduce the formula The spectral similarity index can be calculated to be 60.52%.

[0064] The embodiment of the present invention further discloses an evaluation system for evaluating the similarity of spectra of light sources with different color temperatures, including:

[0065] Power spectrum module: obtains the power spectra of the two colored light sources to be evaluated;

[0066] Luminous brightness spectrum module: Determine the luminous brightness spectrum of each colored light source based on the power spectrum;

[0067] Similarity calculation module: determines whether the color temperatures of two colored light sources are the same. If the color temperatures are the same, the similarity of the two colored light sources is calculated according to the natural spectrum similarity index formula; if the color temperatures are different, the similarity of the two colored light sources is calculated according to the spectrum similarity index formula considering the color temperature.

[0068] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0069] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for evaluating the similarity of spectra of light sources with different color temperatures, characterized in that: The specific steps are as follows: Step 1: Obtain the power spectra of two colored light sources to be evaluated; Step 2: Determine the luminous brightness spectrum of each of the colored light sources according to the power spectrum; Step 3: Determine whether the color temperatures of the two colored light sources are the same. If the color temperatures are the same, calculate the similarity of the two colored light sources according to the natural spectrum similarity index formula; if the color temperatures are different, calculate the similarity of the two colored light sources according to the spectrum similarity index formula considering the color temperature.

2. The method for evaluating the similarity of spectra of light sources with different color temperatures according to claim 1, characterized in that: The step 1 comprises: placing the two colored light sources to be evaluated in a dark room, measuring the light intensity of each wavelength band of each colored light source by a photometer, and determining the power spectrum of each colored light source.

3. The method for evaluating the similarity of spectra of light sources with different color temperatures according to claim 1, characterized in that: The step 2 comprises: Integrating the power spectrum with the human eye viewing function to obtain the luminous flux of each wavelength band of each of the colored light sources; Determine a photometric function between the radiation power of the colored light source and the luminous flux according to the luminous flux; The power spectrum is multiplied by the luminosity function to obtain the luminous brightness spectrum.

4. The method for evaluating the similarity of spectra of light sources with different color temperatures according to claim 1, characterized in that: The calculation formula of the luminescence brightness spectrum is: L i (λ,T)=I i (λ,T)×V(λ,T); Among them, I i (λ,T) represents the power spectrum of the i-th colored light source, V(λ,T) represents the luminosity function, L i (λ,T) represents the luminous brightness spectrum of the i-th colored light source; λ represents the wavelength, and T represents the color temperature.

5. The method for evaluating the similarity of spectra of light sources with different color temperatures according to claim 1, characterized in that: The natural spectrum similarity index formula is: Among them, SRI represents the natural spectrum similarity index, L(λ,T) represents the overlapping area between the luminous brightness spectrum and the blackbody radiation, and L BR (λ,T) represents the brightness spectrum of blackbody radiation.

6. The method for evaluating the similarity of spectra of light sources with different color temperatures according to claim 5, characterized in that: The spectral similarity index formula considering color temperature is: Among them, SRI CCT Indicates the spectral similarity index considering color temperature, CCT1 indicates the color temperature of the comparison light source, and CCT2 indicates the color temperature of the target light source.

7. An evaluation system for evaluating the similarity of spectra of light sources with different color temperatures, using an evaluation method for evaluating the similarity of spectra of light sources with different color temperatures as claimed in any one of claims 1 to 6, characterized in that: include: Power spectrum module: obtains the power spectra of the two colored light sources to be evaluated; Luminous brightness spectrum module: determining the luminous brightness spectrum of each of the colored light sources according to the power spectrum; Similarity calculation module: determines whether the color temperatures of the two colored light sources are the same. If the color temperatures are the same, the similarity of the two colored light sources is calculated according to the natural spectrum similarity index formula; if the color temperatures are different, the similarity of the two colored light sources is calculated according to the spectrum similarity index formula considering the color temperature.

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