彩色相机广泛应用于印刷工业、形象艺术、医疗、环境等多个应用领域。在节约成本的前提下,为了保证相机显色效果维持特定范围,提出了利用单通道预滤光片同时对彩色相机总光谱响应曲线进行校正的方法。预滤光片模拟准确度取决于卢瑟条件的匹配程度,由于滤光片材质、膜层设计、制造工艺水平等的限制,完全符合卢瑟条件是不可能的,单通道预滤光片光谱匹配则会有更大的技术难度。从影响预滤光片模拟准确度的因素出发,采用连续可调谐均匀单色照明光源系统对彩色CCD进行高精度相对光谱响应测试,通过选取合适的评价函数模型,对预滤光片光谱透过率进行仿真拟合,得到最优光谱透过率曲线。以国际照明委员会(CIE)推荐的14种标准测试颜色为参考,采用CIE2000色差公式,对校正前后彩色相机进行理论色差计算。结果表明: 增加预滤光片后,平均色差降低73%,相机显色效果得到显著提升。

Color cameras are widely used in the printing industry, graphic arts, medical area, environment and many other applications. In order to save cost and maintain high colorimetric accuracy, a method that utilizing a single-channel pre-filter to calibrate color camera′s spectral sensitivity curve was put forward. The pre-filter′s simulation accuracy depended on the degree of matching Luther conditions, and it was impossible to match perfectly due to the limitation filter material, the film design, and the non-ideal filter fabrication. The goal of this work was to design the target curve according to analyzing the influence factor of the simulate accuracy, using the continuously tunable monochromatic light source system to test the color CCD relative spectral response, selecting appropriate evaluation function model to simulate theoretical spectral transmittance, referring the CIE standard test colors and using CIE2000 color formula to evaluate the theoretical color error. This work shows that after increasing the pre-filter, the mean change of the color error is about 73%, and the color effect of the camera has been enhanced significantly.