## 4 3D Integral Imaging Display Experimental Results
\begin{table}
\begin{tabular}{c c} \hline \hline
**Description** & **Parameters** \\ \hline Total number of elemental images (EIs) & 11 (H) \(\times\) 11 (V) \\ Resolution on each EI & 2000 (H) \(\times\) 2000 (V) \\ Sensor pitch & 15 mm (H) \(\times\) 15 mm (V) \\ Focal length & 18.1 mm \\ Field-of-view of each sensor & 50 degree \\ Angular resolution & 0.025 degree \\ Distances between the surface of & Pyramid: 190 mm \\ objects and the pickup plane & Box: 490 mm \\
3D scene depth range & 300 mm \\  & Approx. \\ Scene size & 220 mm (H) \(\times\) 120 mm (V) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Specifications of computer-generated integral imaging pickup. Figure 4: Computer-generated 3D scene. (**a**) Two captured elemental images; (**b**) the corresponding depth maps. Another group of experiments for a real 3D scene obtained by the synthetic aperture integral imaging technique was conducted. The 3D scene consists of a white bear toy and a globe with a large depth range of 425 mm. Both objects are over 2000 mm away from the pickup camera array; the parameters of the 3D scene and the synthetic aperture pickup process are shown in Table 3.  
Two of the captured elemental images and the corresponding estimated depth maps are shown in Figure 6. In the estimated depth maps, the pixel color represents the relative position of the corresponding 3D points recorded by the camera. In the depth map, pixel intensities encode the depth information of the points captured by the camera. Objects that are farther away appear with higher intensity values. For the real 3D scene group, the nearest surface (\(z_{rmr}\)) is located at 1975 mm in front of the pickup camera. We rescale the depth range (\(d_{s}\)) to 100 mm. Based on Equations (1)-(3), two reference planes were selected to encompass the 3D scene at 1975 mm and 2400 mm. The corresponding virtual pinhole arrays are calculated at 2025 mm and 2350 mm. Two ref  
Figure 5: Synthetically generated elemental image arrays for 3D display: (**a**) Using the conventional SPOC method, preserving a large depth range of 300 mm. (**b**) Depth range rescaled to 80 mm; however, the field-of-view exceeds the capacity of the device. (**c**) Depth range rescaled to 80 mm along the z axis, with the field-of-view resized on the x-y axis by a factor of 0.5. \begin{table}
\begin{tabular}{c c} \hline \hline
**Description** & **Parameters** \\ \hline Total number of elemental images (EIs) & 5 (H) \(\times\) 8 (V) \\ Resolution on each EI & 2808 (H) \(\times\) 1872 (V) \\ Sensor pitch & 36 mm (H) \(\times\) 24 mm (V) \\ Focal length & 35 mm \\ Field-of-view of each sensor & 14 (H) \(\times\) 9.4 (V) degree \\ Angular resolution & 0.005 degree \\ Distances between the surface of objects and & Globe: 1975 mm \\ the pickup plane & Bear toy: 2400 mm \\
3D scene depth range & 425 mm \\ Approx. \\ Object sizes & 330 mm (H) \(\times\) 220 mm (V) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Specifications of synthetic aperture integral imaging pickup—real 3D scene. erence planes are synthetically captured by their respective virtual pinhole array, positioned at \(-\)50 mm and 50 mm relative to the plane. By superimposing the synthetic elemental images, the synthetic elemental image array is regenerated with a rescaled depth range of 100 mm, centered at the display plane. The scene size is about 330 mm (H) \(\times\) 200 mm (V). Considering the field-of-view of the virtual pinhole array within the depth range, the synthetic capture area is approximately 117 mm (H) \(\times\) 72 mm (V) at \(\pm\)50 mm from the pinhole array. The 3D scene is fully recorded by the regenerated elemental image array with a resizing factor of 0.35. Figure 7 illustrates the synthetically captured elemental image arrays for the 3D display. The generated elemental image array by the conventional SPOC method preserves the original depth and size information of the 3D scene, as shown in Figure 7a.