混合式光场相机在聚焦与非聚焦模式下的超分辨重聚焦仿真

光场描述了光在自由空间传播的全四维信息,光场相机可用来获得光场图像。在传统的光场相机中,最终获得图像的空间分辨率受限于微透镜阵列中透镜的个数。聚焦型光场相机相较于传统光场相机能够获得更高的空间分辨率,但是以牺牲其角度分辨率作为代价。在Zemax中建立了传统光场相机与将聚焦光场相机的成像模型,仿真获得了两种光场相机的光场图像,分析了两种不同类型光场相机采样模式的区别。提出将可变焦液体透镜阵列放置在光场相机中,可以同时获得聚焦和非聚焦两种模式下的光场图像。根据记录的光场信息,讨论了相应的重聚焦方法,计算仿真了在不同景深下的重聚焦图像,并提出了一种基于图像融合和超分辨率重构的方法来提高重聚焦图像的分辨率,最终在相同的景深范围内获得了3倍于传统光场相机分辨率的重聚焦图像。

Computer simulation for hybrid plenoptic camera super-resolution refocusing with focused and unfocused mode

Light field is a representation of full four-dimensional radiance of rays in free space. Plenoptic camera is a kind of system which could obtain light field image. In typical plenoptic camera, the final spatial resolution of the image is limited by the numbers of the microlens of the array. The focused plenoptic camera could capture a light field with higher spatial resolution than the traditional approach, but the directional resolution will be decreased for trading. Two models were set up to emulate the 4D light field distribution in both the traditional plenoptic camera and the focused plenoptic camera respectively. The 4D light field images of the two kinds of plenoptic camera were simulated by the software ZEMAX. The differences of sampling methods of the two kinds of plenoptic camera were analyzed. A variable focal length microlens array was presumed to be used in plenoptic camera to implement both focused and unfocused light field imaging. Based on the recorded light field, the corresponding refocusing process was discussed then. The refocused images at different depth were calculated. A new method of enhancing the resolution of the refocused images by image fusion and super resolution theories was presented. A reconstructed all in-focus image with resolution of 3 times of traditional plenoptic camera and same depth of field was achieved finally.