Research on spatial resolution of a single light field camera based on forward ray tracing technique
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摘要:
在三维场景重建过程中，光场相机的空间分辨率会影响可恢复的空间细节和深度分辨率，从而影响三维重建的准确性。因此，对光场相机的空间分辨率进行计算与分析，对于高分辨率和低分辨率区域的识别十分重要。本文利用前向光线追迹技术的高精度优点，研究了一种基于前向光线追迹技术的光场相机空间分辨率计算方法。对不同微透镜阵列排列方式下的光场相机1.0和2.0的空间分辨率进行了定量计算和比较。进一步研究了不同的主镜头逆放大率（
M l ）对光场相机深度分辨率的影响。结果表明，光场相机在物平面与光轴交点附近以外的区域具有较高的深度分辨率。光场相机2.0在(0,0,0)附近区域的深度分辨率优于光场相机1.0。对于正方形排列的微透镜阵列，光场相机2.0的横向分辨率较光场相机1.0略有提升。光场相机1.0的深度分辨率随着M l 的增大而逐渐降低。Abstract:In the process of 3D scene reconstruction, the spatial resolution of the light field camera (LFC) affects the recoverable spatial details as well as the depth resolution, thereby influencing the accuracy of the 3D reconstruction. Therefore, calculating and analyzing the spatial resolution of the LFC is crucial for identifying the high and low resolution regions. In this paper, a calculation method for the spatial resolution of an LFC is explored based on the forward ray-tracing technique, which has the advantage of high accuracy. The spatial resolutions of LFC 1.0 and LFC 2.0 under different microlens array configurations are quantitatively calculated and compared. In addition, the effects of the inverse magnification (
M l ) of the main lens on the depth resolution of the LFC are investigated. The results show that the LFC exhibits higher depth resolution in regions away from the intersection of the object plane and the optical axis. The depth resolution of LFC 2.0 near the region of (0,0,0) is better than that of LFC 1.0. For a microlens array arranged in a square pattern, the lateral resolution of LFC 2.0 shows a slight improvement over that of LFC 1.0. The depth resolution of the LFC 1.0 gradually decreases asM l increases.-
Key words:
- light field camera /
- spatial resolution /
- reconstruction /
- ray tracing /
- depth resolution
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图 1 光场相机的成像原理示意图
Figure 1. Schematic diagram of the imaging principle of the light field camera
图 4 正方形微透镜阵列光场相机1.0沿Z轴的深度分辨率
Figure 4. Depth resolution along Z axis of light field camera 1.0 with square microlens array
图 5 正方形微透镜阵列光场相机1.0沿X轴的横向分辨率
Figure 5. Lateral resolution along X axis of light field camera 1.0 with square microlens array
图 6 正方形微透镜阵列光场相机1.0沿Y轴的横向分辨率
Figure 6. Lateral resolution along Y axis of light field camera 1.0 with square microlens array
图 7 前向光线追迹和逆向光线追迹技术的空间分辨率结果对比
Figure 7. Comparison of spatial resolution calculation results between forward ray tracing and backward ray tracing techniques
图 8 蜂窝型微透镜阵列光场相机1.0沿Z轴的深度分辨率
Figure 8. Depth resolution along the Z axis of light field camera 1.0 with honeycomb microlens array
图 9 蜂窝型微透镜阵列光场相机1.0沿X轴的横向分辨率
Figure 9. Lateral resolution along the X axis of light field camera 1.0 with honeycomb microlens array
图 10 蜂窝型微透镜阵列光场相机1.0沿Y轴的横向分辨率
Figure 10. Lateral resolution along the Y axis of light field camera 1.0 with honeycomb microlens array
图 11 正方形微透镜阵列光场相机2.0沿Z轴的深度分辨率
Figure 11. Depth resolution along Z axis of light field camera 2.0 with square microlens array
图 12 正方形微透镜阵列光场相机2.0沿X轴的横向分辨率
Figure 12. Lateral resolution along X axis of light field camera 2.0 with square microlens array
图 13 正方形微透镜阵列光场相机2.0沿Y轴的横向分辨率
Figure 13. Lateral resolution along Y axis of light field camera 2.0 with square microlens array
图 14 蜂窝型微透镜阵列光场相机2.0沿Z轴的深度分辨率
Figure 14. Depth resolution along Z axis of light field camera 2.0 with honeycomb microlens array
图 15 蜂窝型微透镜阵列光场相机2.0沿X轴的横向分辨率
Figure 15. Lateral resolution along X axis of light field camera 2.0 with honeycomb microlens array
图 16 蜂窝型微透镜阵列光场相机2.0沿Y轴的横向分辨率
Figure 16. Lateral resolution along Y axis of light field camera 2.0 with honeycomb microlens array
表 1 光场相机1.0的光学参数
Table 1. Parameters of the light field camera 1.0
d1
(mm)d2
(mm)fm
(mm)f
(mm)l1
(mm)lm
(mm)Pm
(mm)Px
(μm)0.6 - 0.6 100 200 200 0.1045 5.5 
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表 2 光场相机2.0的光学参数
Table 2. Parameters of the light field camera 2.0
d1
(mm)d2
(mm)fm
(mm)f
(mm)l1
(mm)l2
(mm)Pm
(mm)Px
(μm)0.54 5.4 0.6 100 200 200 0.1045 5.5
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表 3 不同Ml下光场相机1.0的光学参数
Table 3. Parameters of the light field camera 1.0 with different Ml
d1 (mm) fm (mm) f (mm) Ml l1 (mm) lm (mm) Pm (mm) Px (μm) 0.6 0.6 100 1 200 200 0.1045 5.5 0.6 0.6 100 1.5 250 166.667 0.1045 5.5 0.6 0.6 100 2 300 150 0.1045 5.5 0.6 0.6 100 2.5 350 140 0.1045 5.5
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