色空间对HDRI亮度测量方法的影响

Influence of Color Spaces on Luminance Measurement Method Based on HDRI

相机内置预处理环节中的白平衡、色度空间转换是数码成像过程中的重要环节,sRGB和Adobe RGB是数码相机2种常用的色空间。为进一步研究色空间对HDRI亮度测量方法的影响,在荧光灯照明的实验室,分别利用sRGB和Adobe RGB色空间对色板成像,测量该亮度测量方法中各色板的标定因数,计算各色板标定因数的相对不确定度。实验结果表明:2种不同色空间获得的标定因数不同,且Adobe RGB色空间标定因数相对不确定度的平均值小于sRGB色空间的;色空间改变后,标定因数需要重新进行标定,且优先选用色域较宽的Adobe RGB色空间。

White balance and color space conversion in the inner preprocessing course of camera are important parts in the digital imaging process, sRGB and Adobe RGB color spaces are two color spaces in common use by digital camera. The influence of color temperature and white balance on the luminance measurement method based on high-dynamic range image（HDRI） is studied in the literature. For further study of the influence of two color spaces including sRGB and Adobe RGB on the luminance mea- surement method based on HDRI, the colored boards are imaged in the fluorescent lighting laboratory to measure the calibration fac- tors in two color spaces, and calculate the relative error between each calibration factor and the mean one. Calibration factors calcu- lated in two color spaces are different. In addition, the mean value of varous calibration factors of sRGB color space is larger than that of Adobe RGB color space. The experimental result shows that as color spaces are different, calibration factors need re-calibrating. In addition, when the method is used to measure luminance, Adobe RGB color space is preferred to.