Application of Hyperspectral Imaging: Component Color Difference Testing

本實驗探討了使用采用高光譜顏色測量設備，評估元器件塑料外殼顏色差異的全過程。

This experiment explores the complete process of using a hyperspectral color measurement system to evaluate color differences in plastic casings of electronic components.

「檢測環境 / Testing Environment」

首先，我們把待測的塑料外殼逐一安放在暗室內的水平位移平臺上，暗室頂部布置有條形鹵素燈作為照明，平臺勻速移動的同時，一臺覆蓋400–1000nm、光譜分辨率優于2.8nm的高光譜相機以線性推掃方式采集完整光譜圖像；所有Lab計算均采用D65光源與2°視角的參數組合。

The plastic casings to be measured were individually placed on a horizontal translation stage inside a darkroom. A halogen strip lamp was installed at the top of the darkroom to provide uniform illumination. While the stage moved at a constant speed, a hyperspectral camera covering 400–1000 nm with a spectral resolution better than 2.8 nm captured complete spectral images in a push-broom scanning mode. All Lab value calculations were performed using the D65 illuminant and a 2° standard observer angle.

設備規格參數

光譜范圍：400~1000nm

光譜分辨率：≤2.8nm

光譜波段數：256

F數：F/2.6

空間像素數：320

探測器類型：CMOS

探測器接口：GigE

有效位深：12bits

Equipment Specifications

- Spectral Range: 400–1000 nm

- Spectral Resolution: ≤ 2.8 nm

- Number of Spectral Bands: 256

- F-Number: F/2.6

- Spatial Pixels: 320

- Detector Type: CMOS

- Interface: GigE

- Effective Bit Depth: 12 bits

「高光譜圖像 / Hyperspectral Image」

「光譜曲線 / Spectral Curves」

「Lab值 / Lab Values」

測試結論OK表示當前選區計算出的?E＜0.5

測試結論NG表示當前選區計算出的?E＞0.5

- OK: Indicates that the calculated ?E of the current region is < 0.5

- NG: Indicates that the calculated ?E of the current region is > 0.5

ΔE值解釋標準：

0-1: 人眼幾乎無法察覺的顏色差異。

1-2: 只有經過訓練的人才能察覺到細微差異。

2-3: 未經過訓練的人也能察覺到輕微的顏色差異。

3-6: 顯而易見的顏色差異。

6-12: 強烈的顏色差異。

>12: 顏色不同

?E Interpretation Criteria:

- 0–1: Color difference is virtually imperceptible to the human eye.

- 1–2: Only trained observers can detect slight differences.

- 2–3: Untrained individuals can perceive minor color variations.

- 3–6: Clearly visible color difference.

- 6–12: Strong color difference.

- >12: Colors are completely different.

「總結 / Conclusion」

通過反射率曲線可見各個樣品的曲線均不相同，同時在高光譜圖像中人眼即可分辨出顏色差異，而由Lab值計算結果亦表明各樣品存在明顯的顏色差異。

The reflectance curves show distinct spectral characteristics for each sample. Color differences are visually discernible in the hyperspectral images, and the calculated Lab values further confirm significant color variations among the samples.