中文摘要：

双向反射分布函数（BRDF）用于描述物体表面的光反射分布规律,从该函数的定义出发,简化了函数的分析模型,通过实验获取了冷轧板表面光散射的空间分布曲线,并基于BRDF经验模型的思想提出一个具有四参数的表面BRDF修正数学模型;进一步针对实验数据,基于共轭梯度优化算法对模型中各参数进行拟合,得到一个可以模拟大角度范围入射情况的冷轧板表面的光散射模型,实验结果表明该模型准确度较高,为进一步设计表面成像系统以及构建冷轧板表面光散射虚拟模型提供理论依据。

英文摘要：

The surface scattering properties can be described well by bidirectional reflectance distribution function（ BRDF ）.It starts with the definition of this function, simplifying the analysis model. The distribution curve of the surface scattering of cold steel is obtained by experiment.Then a modified model with four parameters on the base of empirical model is proposed.The parameters are optimized by conjugate gradient method.And the result shows that this optimization model is accurate and it can simulate the surface scattering of cold steel in a wide range of angle. This provides the theoretical basis for further designing the surface imaging system and building the virtual surface scattering model of cold steel.