相位差异散斑法图像复原技术

Image restoration by phase-diverse speckle

为了克服大气湍流和光学成像系统像差引起的波前相位畸变,提出利用相位差异散斑法同时采集焦面和离焦面通道的单帧短曝光图像来估算波前相位畸变。结合夏克哈特曼波前探测器设计了针对扩展目标的相位差异散斑法高分辨率成像和相位估计对比实验,通过定量移动高精密平移台获得焦面和离焦面图像,并将解算的波前面形与夏克哈特曼波前探测器实测的波前面形进行对比,验证了相位差异散斑法提高图像分辨率和正确解算波前相位的能力。实验结果表明,估算的波前相位面形和夏克哈特曼实测面形趋势有较好的一致性,恢复后图像分辨率提高了12%,表明该方法是大口径光电成像系统较为理想的图像恢复技术之一。

In order to overcome the wave-front distortion caused by atmosphere turbulence and optical system aberration,the Phase-Diverse Speckle（PDS） method was used to collect simultaneouslly two or more short-exposure optical images formed by focusing or defocusing to estimate both the object and the wave-front phases.To verify the improvement of image resolution and phase estimation of PDS method,a comparison experiment on high-resolution imaging and phase estimation comparison was carried out based the PDS method and a Shack-Hartmann sensor.By shifting the high accurate translation stage at a certain distance,the focusing and defocusing images were obtained,then the wavefront phase based on the image was camparied with that from the Shack-Hartmann sensor.Experiment results indicate that the estimated wave-front phase is highly according with that detected by Shack-Hartmann and the resolution of the restored image can increase by 12% compared with the origin image formed by focus plane.In conclustion,the proposed method can be used to restore the degradative images in large aperture telescopes.