三基色显示中白点坐标对立体色域的影响及其准确计算

Influence of white point on stereo color gamut of three primary display systems and their accurate calculation

色域表示了显示系统的显色能力,是显示系统的重要指标,它不仅受到每个基色参数的影响,还和显示系统的白点坐标相关,不同的标准给出的白平衡点参考值并不相同,因此需要研究各种条件下,不同白点坐标对显示系统色域的影响。利用全微分公式,将影响显示系统立体色域的因素划分为由光源参数直接改变引起立体色域改变的直接部分和光源参数引起白点色坐标改变的间接部分,两者影响相加可以得到更准确的立体色域。以满足Rec.2020标准,三基色中心波长为630,532,467 nm,光谱宽度为1 nm的光源为例,每0.01x色坐标对立体色域影响为0.80%,而每0.01y色坐标对立体色域影响为-2.15%。当选用白点色坐标不变的假设时,绿光谱宽对立体色域影响最大,应维持绿光较窄谱宽以保证高色域。当选用强度不变的假设时,三种基色对立体色域的影响相当,考虑到红光对白点色坐标影响最小,这时可以适当牺牲红光的光谱宽度以平衡立体色域和光谱宽度。

Color gamut represents the capability of the display system to display colors.It is an important indicator of the display system.Color gamut is not only affected by each primary color but also related to the white point coordinates of the display system.Different standards have different reference white points,so it is necessary to study the influence of different white point coordinates on the color gamut of the display system under various conditions.By using the total differential formula,the factors affecting the stereo color gamut of the display system are divided into two parts:the direct part caused by the light source parameters and the indirect part caused by the white point color coordinate.Considering the addition of the two effects,a more accurate stereo color gamut can be obtained.For a light source that meets the Rec.2020 standard,the central wavelengths of the three primary colors are 630,532,467 nm,and the spectral width is 1 nm,every 0.01x color coordinate increases the stereo color gamut by 0.80%,and every 0.01y color coordinate reduces the stereo color gamut by-2.15%.When the assumption that the color coordinates of the white point remain unchanged is selected,the green spectral width has the greatest impact on the stereo color gamut,and a narrow spectral width of green light should be maintained to ensure a high color gamut.When the assumption of constant intensity is selected,the three primary colors have similar effects on the stereo color gamut.Considering that the red light has the least influence on the color coordinates of the white point,the spectral width of the red light can be appropriately sacrificed to balance the stereo color gamut and the spectral width.