Large Macbeth® ColorChecker®
X-Rite ColorChecker® 是使用科學方法的獨特測試圖案，專為協助確定任何演色系統的全彩平衡或光密度而設計。該行業標準可針對以科學方法準備的24個色彩方塊構成的「測試圖案」，提供與其進行的非主觀比較。每個色彩方塊都表示一個自然物件(人的皮膚、樹葉、藍天等)，從而提供可計量值的定性參考。在整個可見光譜中，每種顏色都以相同方式來反射光，因而能在不同的照明選項之間保持色彩一致性。這些測試板適用於包括光譜學、機器視覺、攝影、平面藝術、電子出版及電視在內的某些應用。
The X-Rite ColorChecker® chart provides an easy way to recognize and evaluate the many factors that can affect color reproduction. To evaluate the effect of varying any given factor, simply compare the chart’s color image to the actual ColorChecker®. It is ideal for testing and standardizing color inspection and analysis systems.
The X-Rite ColorChecker® SG improves on the original 24 patch design by offering a wide array of 140 colors. Specifically designed for digital photography, the X-Rite ColorChecker® SG provides a semi-gloss background with whiter whites, blacker blacks, and more saturated colors. The RezChecker can measure resolution according to the latest international standard (ISO 12233). Gloss gray patch targets have an extended dynamic range (density = 2.4) and can also be used to measure imaging noise. However, specular reflections from the gloss surface may occur for illumination geometries less than 45°/0°. Matte gray patch targets have a small dynamic range (density = 1.6), but are more suited to narrow illumination geometries, such as those used in endoscope imaging.
The color names for each of the squares are given along with the chromaticity coordinates x and y and the luminous reflectance factor Y. Also provided are the Munsell notations and the ISCC/NBS names.
A particularly useful function of the X-Rite ColorChecker® is in determining the L*a*b* values of the test subject. The L*a*b* color model (CIELAB) is the international color measurement standard used to describe all the colors visible to the human eye. It is created to be independent from any device, thus maintaining the consistency in color. The L*a*b* standard consists of "L" (bright/dark axis), "a" (red/green axis), and "b" (yellow/blue axis) components. A positive value of a* describes the redness of the color, a negative a* the greenness. Similarly, a positive b* denotes yellow, and a negative b* denotes blue.