在颜色世界里,人们遇到最多的是白和近白色。基于目视感知而判断反射物体所能显白的程度,术语上称之为白度。与其他颜色一样,白色也是三维空间的量,而对大多数色觉正常的观察者来说,可以将一定范围内的光反射比、色饱和度和主波长不同的白色,按其白度的高低排列成一维的白度序列,从而进行定量的评价。这样的评价与客观物理仪器测量的数据、合理而有效的白度公式计算出的白度值具有良好的相关性。但是,人们对白色的评价不仅有各自的心理感受上的特征而且往往认为带有这种或那种色调(通常为偏蓝)的“白”更白些。实践证明,人们的爱好与习惯等复杂的心理因素都影响着对白度的目视判断。另外,实验方法、照明与观察条件、观察者条件与熟练程度、所从事的特殊职业和技术色疲惫性职业病、被评价样品白的性质和白的周围衬色等都起着一定的影响。所以,想要全面考虑这些因素来对白度进行合理的定量评价是困难的,尤其是在出现了荧光增白剂而扩大了白色范围后,更是如此。 In the color world, people encounter the most is white and nearly white. The degree to which a reflective object can appear white based on visual perception is termed whiteness. As with other colors, white is also an amount of three-dimensional space. For most observers with normal color vision, a white light having a range of light reflectance, color saturation and dominant wavelength can be measured according to its whiteness Arranged in one-dimensional whiteness sequence, so as to quantitatively evaluate. This evaluation has good correlation with the data measured by objective physical instruments and the whiteness value calculated by a reasonable and effective whiteness formula. However, people’s perceptions of white not only have their own psychological characteristics, but they also tend to consider the “white” whites with one or more hues (usually bluish) whiter. Practice has proved that people’s hobbies and habits and other complex psychological factors affect the visual judgment of whiteness. In addition, experimental methods, lighting and observation conditions, observer conditions and proficiency, occupational diseases and occupational diseases, fatigue and occupational diseases, evaluation of the nature of the sample white and white lining have played a certain influence. Therefore, it is difficult to take a full account of these factors in order to rationally and quantitatively evaluate the whiteness, especially after the whiteness has been broadened by the presence of optical brighteners.