光圈景深联合延拓成像方法与关键技术研究

In traditional photoelectric imaging system, the aperture and the depth of field restricts each other. When we designing an optical system with large aperture, aberrations are always difficult to eliminate. To solve the problems above, this project proposes a new photoelectric imaging technology which could extend both the aperture and the depth of field at the same time. It is mainly consisted of two parts, the iamge acquiring device for non-conjugated equal-blurred intermediate images, and the image prcessing device. Its core is controlling and making use of the aberration of the optical system, which has large aperture and long depth of field. By adding a phase mask in the equal-blurred image acquiring device, the target of the object side is encoded, the OTF of the optical system becomes insensitive to defocus within the designed depth of filed, loss of some spatial frequency is avoided and equal-blurred intermediate images are acquired. Then referring to priori coding knowledge and additional constraints, the intermediate image is decoded through digital signal processing, and clear object information within the designed depth of field is recovered. A fast imaging system with low illumination, large aperture and long depth of field is achieved. By doing reserch on related theories, such as equal-blurred imaging methods, multiple wavefront coding technology, and image decoding technology, the project explores a new high-performance photoelectric imaging principle and method, lays theoretical and technical foundation for comprehensively improving the perfomance of the photoelectric imaging system.

针对传统光电成像系统光圈和景深互相制约的矛盾问题和大光圈系统设计时像差难以消除的难题，项目提出一种光圈景深联合延拓的光电成像新技术，它主要由非共轭等模糊中间像获取装置和图像处理装置组成。其核心是控制并利用成像系统大光圈长景深设计时的像差，通过等模糊中间像获取装置的相位掩模作用对物方目标信息进行编码，使光学系统的光学传递函数对所设计景深范围内对应的所有目标信息具有离焦不敏感特性，避免部分空间频率的丢失，获取等模糊中间像。然后利用先验的编码知识及其他附加约束条件，通过数字信号处理的方法对所得的中间图像进行解码，恢复出设计景深范围内的清晰目标信息，实现快速、低照度、光圈景深联合延拓等高性能成像。项目通过开展相关理论研究、等模糊成像方法研究、多重波前编码技术研究、图像解码技术研究，探索出一种全新的高性能光电成像原理与方法，为全面提高光电成像系统性能奠定理论与技术基础。

针对传统光电成像系统光圈和景深互相制约的矛盾问题和大光圈系统设计时像差难以消除的难题，项目提出一种光圈景深联合延拓的光电成像新技术。项目对波前编码技术的物理本质进行了深入分析，开展了像面能量分布特性研究，建立了相关数学模型；进行非共轭等模糊成像方法研究，进一步明确了光线位置和能量的互补特性；开展多重波前编码技术研究，对系统的调制传递函数和点扩散函数的通用表示形式进行了推导，获得了优化的通用共掩模与差异掩模组合设计方法；进行了成像掩模板结构的设计、加工与测试，获得了符合设计要求的掩模板样品，实际经验逐步丰富，精度逐步提高；结合多重波前编码图像退化模型，进行针对性的数字图像解码算法设计，实现了编码图像的智能解码复原；开展了加工装调基础理论研究，基于某监控安防成像系统进行了验证实验研究，获得了较好的结果；结合技术指标进行了对比验证系统和原理样机的优化设计和多组验证试验，获得了理想的试验结果。.项目完成了预期全部研究内容，突破了光圈景深联合延拓成像方法、多重波前编码组合优化设计、波前编码图像解码等研究中的关键技术，完成光圈景深联合延拓的成像原理样机。