Mei Di, Luan Yinsen, Li Xiangchao, Wu XiJiang
Opt Lett. 2024 Feb 15;49(4):965-968. doi: 10.1364/OL.507898.
The imaging process of the light field (LF) camera with a micro-lens array (MLA) may suffer from multiple aberrations. It is thus difficult to precisely calibrate the intrinsic hardware parameters and calculate the corresponding point spread function (PSF). To build an aberration-aware solution with better generalization, we propose an end-to-end imaging model based on the differentiable ray tracing. The input end is the point source location, and the output end is the rendered LF image, namely, PSF. Specially, a projection method is incorporated into the imaging model, eliminating the huge memory overhead induced by a large array of periodic elements. Taking captured PSF images as the ground truth, the LF camera is calibrated with the genetic algorithm initially and then the gradient-based optimization. This method is promising to be used in various LF camera applications, especially in challenging imaging conditions with severe aberrations.
带有微透镜阵列（MLA）的光场（LF）相机的成像过程可能会受到多种像差的影响。因此，精确校准固有硬件参数并计算相应的点扩散函数（PSF）具有一定难度。为构建一种具有更好通用性的像差感知解决方案，我们提出了一种基于可微光线追踪的端到端成像模型。输入端是点源位置，输出端是渲染后的LF图像，即PSF。特别地，一种投影方法被纳入成像模型，消除了由大量周期性元素阵列引起的巨大内存开销。以捕获的PSF图像作为基准真值，首先使用遗传算法对LF相机进行校准，然后进行基于梯度的优化。该方法有望应用于各种LF相机应用中，特别是在像差严重的具有挑战性的成像条件下。
