This standard specifies the visual evaluation method for metamerism. This standard applies to the visual evaluation of metamerism and the estimation of color difference. GB/T 15610-1995 Visual evaluation method for metamerism GB/T15610-1995 Standard download decompression password: www.bzxz.net
This standard specifies the visual evaluation method for metamerism. This standard applies to the visual evaluation of metamerism and the estimation of color difference.

National Standard of the People's Republic of China
Method for visual evaluation of metamerism
Method for visual evaluation of metamerism1 Main content and scope of application
This standard specifies the visual evaluation method of metamerism. This standard is applicable to the visual evaluation and color difference estimation of metamerism. 2 Referenced standards
GB5698 Color terminology
GB250 Grey scale for evaluating color change
3 Standard light source and colorimetric components for evaluation
3.1 Standard light source for evaluation
Standard light source Dss and standard light source A are used for evaluation. 3.2 Colorimetric conditions
3.2.1 Evaluation field of view is 10°
3.2.2 Illumination conditions
When evaluating the sample, the illumination of the observation area should be 1 000 ± 200 [x, 3.2.3 Geometric conditions
Use any of the following two lighting observation methods: 3.2.3.1 (0/45)
GB/T 15610--1995
The illumination light illuminates the sample vertically from top to bottom, and the angle between the optical axis of the illumination light beam and the normal of the sample surface should not exceed 10°. The observer observes in a direction that is 45° to the normal of the sample surface with an error of no more than ±5°. 3.2.3.2 (45/0)
The axis of the illumination light beam is 45° to the normal of the sample surface (the error does not exceed ±5\), and the light angle between the observation direction and the normal of the sample should not exceed 10°. The angle between any ray of the illumination beam and the axis of the illumination beam should not exceed 5°. The same limitation should also be observed in the viewing line of sight.
3.2.4 Background and surrounding environment
The evaluation area should be shielded by a screen or a permanent building to prevent the interference of stray light. The color of the screen should be neutral gray (Y=30~40). The background color of the sample should also be neutral gray (Y30). The glossiness of the background and surrounding surfaces should be within the range of 5~10 gloss units.
4 Conditions of visual evaluators
4. 1 Must be a person with normal color vision and have experience in color discrimination. 4.2 Strictly follow the specifications and procedures of the visual evaluation. Approved by the State Administration of Technology Supervision on June 19, 1995 and implemented on February 1, 1996
4.3 Age between 18 and 35 years old. bZxz.net
5 Technical requirements for samples to be evaluated
5.1 Product size
The sample area is 5 cmX 5 cm.
5.2 Transparency
GB/T 15610--1995
Generally, opaque samples are selected for light selectivity and color evaluation. If it is necessary to evaluate semi-transparent samples, the following requirements should be followed:
5.2.1 When evaluating glossiness
5.2.1.1 The thickness of the sample should be able to avoid reflected light from the back or back of the sample. 5.2.1.2 When evaluating thinner samples, one of the following steps should also be followed: Place an opaque backing plate with the same reflectivity behind the sample: b. Place a backing plate on the back of the sample.
5.2.2 When evaluating color
Even if the sample has little transparency, the backing plate will affect the evaluation results. Therefore, one of the following requirements must be followed. a. Place a backing plate made of the same material on the back of the sample. The material and color of the backing plate should be re-obtainable, stable and durable; b. Place a backing plate with the same light reflectivity on the back of the sample c. Place a black plate (such as a color plate with kneading or black glass) on the back of the sample: d. Place a white plate with a concave reflectivity on the back of the sample. 5.3 The surface state of the evaluated sample and the standard sample should maintain the color and flatness of the sample, the brightness should remain stable, without scratches or stains, and the texture of the substrate should not be exposed, so as not to affect the evaluation accuracy. The product should also have a certain strength. 5.4 Cleaning the sample
5.4.1 Matt samples are generally not suitable for sample cleaning due to their surface characteristics. 5.4.2 If glossy samples need to be cleaned, the following procedures should be followed and performed with caution. Samples with a higher level of gloss can usually be washed with clean water and then gently wiped with a new lens cloth or paper towel. Samples with good durability can be cleaned with a soft cloth or soft brush with a small amount of neutral non-ionic detergent. If such samples are stained with oil stains or spots that are difficult to remove, they can be cleaned with corresponding reagents. After using the above cleaning methods, they should be cleaned with clean water immediately and dried with a new cotton-free paper towel. 5.5 Hold the sample by its edge.
6 Procedure for visual evaluation of metamerism
6.1 According to this standard, when conducting daytime evaluation of metamerism, all samples to be evaluated must be evaluated under the two standard light sources specified in this standard to confirm the degree of metamerism. That is, if a pair of samples have the same visual color under a certain standard light source (as described in Chapter 3), they must be evaluated again under another standard light source with the same observation. If the standard light source D6 is used first, the standard light source A should be used for evaluation afterwards.
6.2 When evaluating the degree of metamerism of the sample, use the standard gray sample card specified in GB250 to determine the color difference level. 6.3 Color difference evaluation method
Put a pair of metamerism samples and standard gray sample cards horizontally in adjacent positions on the same scale, and compare them with different standard gray samples until the best match is found. Record the CIE LAB color difference value (see Table 1). If the color difference is between the levels of adjacent standard samples, use the interpolation method to take the middle value. If necessary, the direction of color difference change can be recorded by describing the change in hue (such as bluer, greener), or saturation change (blacker, darker), or brightness change (brighter, darker).
(4--5)
7 Precision of evaluation results
GB/T 15610—1995
Table 1 Grey sample data
CIE LAL color difference
7.1 When the evaluation process meets the relevant provisions of Chapters 3 to 5, the following definitions of repeatability and reproducibility can be used for evaluation. 7.1.1 Repeatability
In the same laboratory, the same observer re-evaluates the same sample, and the difference between the re-evaluation result and the previous evaluation result should not be greater than half a level of the original matching color difference.
7.1.2 Reproducibility
In different laboratories, different observers or using different standard grey samples, the error between the result obtained and the previous evaluation result should not be greater than half a level of the original color difference. 8 Report
8.1 The report shall include the following contents:
8.1.1 Sample number, glossiness and surface characteristics. 8.1.2 Evaluation procedure.
8.1.3 Observation results, including the color difference of the standard gray scale obtained by comparison. 8.1.4 Number of observers and the results of their color vision test. 8.1.5 Model of standard illuminant used.
Additional remarks:
This standard was proposed by the State Administration of Technical Supervision. This standard is under the jurisdiction of the National Technical Committee on Color Standardization. This standard was drafted by the Institute of Psychology, Chinese Academy of Sciences. The main drafters of this standard are Wang Donghui, Lin Zhongxian and Sun Xiuru.
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