自然场景透过散射介质成像探测实验研究

Experimental Study on Imaging Through Scattering Medium in Natural Scene

散射成像是光学计算成像领域研究的前沿与热点。散斑自相关成像方法因其简单、快速、无损等特性而备受关注。散斑自相关成像的物理基础是光学记忆效应,数学基础是散斑自相关非相干成像模型,重建质量受散斑自相关的高质量提取与背景有效抑制的直接影响。光传输噪声、外界强背景干扰、探测噪声等的存在,会严重降低散斑自相关的对比度,使其精细结构淹没于背景及干扰噪声中,降低目标重建质量甚至无法实现成像。为增强散斑相关成像的适用性,提升强背景噪声干扰下的成像质量,提出一种背景扣除、双边滤波预处理结合多帧叠加平均的方法来提升目标重建质量,并进行了外场自然环境实验研究。实验结果表明,所提方法可对强背景干扰下的目标进行高质量重建。在此基础上,对于不同谱宽照明和不同距离处的目标,实验验证了方法的有效性,重建质量得到明显改善。研究对散射成像技术的非暗室应用及弱光成像相关应用有一定的借鉴意义。

Scattering imaging is the frontier and hotspot in the field of optical computational imaging field.Speckle autocorrelation imaging has attracted increasingly attention due to its efficient,fast,and noninvasive characteristics.The physical basis of speckle autocorrelation imaging is optical memory effect,and the mathematical basis is speckle autocorrelation incoherent imaging model.The reconstruction quality is directly affected by the high quality of speckle autocorrelation extraction and the effective suppression of background.Due to the existence of optical transmission noise,external strong background interference,and detection noise,the contrast of speckle autocorrelation will be seriously reduced,and its fine structure will be submerged in the background and interference noise,reducing the quality of reconstruction and even leading to fail of reconstruction.To enhance the applicability of speckle autocorrelation imaging and to improve reconstruction quality under strong background noise,we propose a strategy based on background subtraction and bilateral filtering pretreatment combined with multi-frame stacking average method,to improve the performance of reconstruction.The natural environment field experiments are carried out,and the experimental results verify the proposed method can realize high quality reconstruction under strong background disturbance.The effectiveness of the method is verified by experiments for targets at different spectral bandwidths of illumination light and different distances,and the reconstruction quality is significantly improved.This study has certain reference significance for the non-darkroom application of scattering imaging technology and the related applications of imaging under weak light conditions.