高光谱成像应用：灰色布料的色差测试

Application of Hyperspectral Imaging: Color Difference Testing of Gray Fabric

色差值是指两个颜色之间的差异，是衡量两个颜色差异的重要指标，只要涉及到颜色的行业，几乎都会用到。色差可用ΔL、Δa、Δb和ΔE表示，其中ΔE值越大表示色差越明显。常用的色差公式包括L*a*b色差公式和ΔE公式。

本次实验采用高光谱相机，对灰色布料样品进行色差检测，通过测量和分析样品的颜色差异来验证该技术的应用效果。

Color Difference refers to the difference between two colors and serves as a key metric for evaluating color variations. It is widely used in industries where color accuracy is critical. Color differences can be expressed using ΔL, Δa, Δb, and ΔE, where a higher ΔE value indicates a more noticeable color difference. Common color difference formulas include the Lab* color difference formula and the ΔE formula.

In this experiment, a hyperspectral camera was employed to test the color difference of gray fabric samples. By measuring and analyzing the color variations of the samples, the effectiveness of this technology was validated.

「测试设备介绍 / Test Equipment」

测试采用的高光谱相机具备400~1000nm的光谱范围检测能力，配合线性推扫成像方案和卤素光源照明系统，将样品置于传送带上进行精准测量。

The hyperspectral camera used in this test features a spectral range of 400–1000 nm. Combined with a line-scan imaging setup and a halogen light source illumination system, the samples were placed on a conveyor belt for precise measurement.

高光谱相机参数 / Hyperspectral Camera Specifications

·光谱范围 / Spectral Range：400~1000nm

·光谱分辨率 / Spectral Resolution：≤2.8nm

·光谱波段数 / Number of Spectral Bands：300

·F数 / F-Number：F/2.0

·空间像素数 / Spatial Pixels：480

·探测器类型 / Detector Type：CMOS

·探测器接口 / Detector Interface：GigE

·有效位深 / Effective Bit Depth：12bits

「高光谱图像 / Hyperspectral Image」

「光谱曲线 / Spectral Curve」

「Lab值 / Lab Values」

计算出的Lab值和ΔE色差值如下图所示：

通过分析获得的高光谱图像和光谱曲线数据，我们计算出Lab值和ΔE值。

其中1号标样区的数据作为基准参考值，以ΔE=0.5为判定阈值。

The calculated Lab values and ΔE color difference values are shown below:

By analyzing the acquired hyperspectral image and spectral curve data, we calculated the Lab values and ΔE values.

The data from the reference area (Sample 1) was used as the benchmark, with a threshold of ΔE = 0.5 for judgment.

测试结论“OK"表示计算的ΔE值小于判定阈值（即ΔE≤0.5），测试结论“NG"表示计算的ΔE值大于判定阈值（即ΔE>0.5）。

Test Conclusion "OK": Indicates that the calculated ΔE value is less than or equal to the threshold (ΔE ≤ 0.5). Test Conclusion "NG": Indicates that the calculated ΔE value exceeds the threshold (ΔE > 0.5).

「总结 / Summary」

测试结果显示，虽然最大ΔE值达到0.83，但仍处于人眼难以辨别的细微差异范围内，这充分体现了高光谱技术在捕捉细微色差方面的优势。

The test results show that although the maximum ΔE value reached 0.83, it still falls within the range of subtle differences that are difficult to discern with the naked eye. This fully demonstrates the unique advantage of hyperspectral technology in detecting minute color variations.