针对声光可调谐滤波器(AOTF)自身固有的因声光互作用导致的成像畸变问题, 利用AOTF的解析表达式和几何像差公式对AOTF相机的畸变特性进行分析, 建立了声光互作用图像畸变模型, 给出了各畸变系数随入射光传播角的变化关系; 并在所构建畸变模型的基础上, 结合两步标定法和双线性内插法对畸变图像进行校正分析。实验结果表明, 未加AOTF相机系统拍摄图像的最大畸变像素位移量为1.6 pixel, 加AOTF相机系统拍摄图像的最大畸变像素位移量为9.0 pixel, 畸变校正后的最大畸变像素位移量为1.4 pixel, 优于未加AOTF相机系统所拍摄的图像。该畸变模型较好地描述了AOTF相机的畸变产生机理及特性, 该方法可以有效地解决AOTF相机成像过程中的图像畸变问题, 在AOTF光谱相机的精确测量方面将有较好的应用前景。

Aiming at the problem of the imaging distortion caused by the acousto-optic interaction, which is inherent in acousto-optic tunable filter (AOTF), the distortion characteristic of AOTF camera is analyzed by AOTF analytic expressions and geometric aberration formulas. The image distortion model of the acousto-optic interaction is established, and the relationship between the distortion coefficient and the incident light propagation angle is showed. The two-step calibration method and the bilinear interpolation method are employed to correct and analyze the distorted image based on the constructed distortion model. The experimental results show that the maximum distortion pixel displacement of the image captured by the no-AOTF camera system is 1.6 pixel, while the maximum distortion pixel displacement of the image captured by the AOTF camera system is 9.0 pixel. The maximum distortion pixel displacement is 1.4 pixel after distortion image is corrected, which is better than the image captured by the no-AOTF camera system. The distortion model is introduced to describe the distortion mechanism and characteristics of AOTF camera. The distortion correction method can solve the problem of image distortion of AOTF camera imaging process effectively, and it has a good application prospect in the accurate measurement of AOTF spectrum camera.