## 2 Depth Rescaling Process (Z Axis)  
To rescale the depth of a captured scene and match the depth capacity of a 3D display system, we processed a depth rescaling method. This implementation works by generating a synthetic elemental image array. The depth range of the scene can then be adjusted in the newly generated elemental image array by setting multiple virtual pinhole arrays in the synthetics capture process. Similar to the MP POC method [16; 18], the generation of synthetic elemental images includes two stages:  
1. Simulated Display: The captured elemental images (from the real pickup process) are first virtually displayed on multiple reference planes (RPs). The parameters in the simulated display process include (i) the pitch of the lenslet array (\(p\)), (ii) the gap (\(g\)) between the captured elemental images and the lenslet array, and (iii) the focal length (\(f\)) of the lenslet array; they should be identical to the parameters of the real pickup process. 2. Synthetic Capture: A virtual pinhole array (VPA) is set up to implement pixel mapping from the reference planes to an image sensor, then regenerate the synthetic elemental image array (EIA). The virtual pinhole array parameters depend on the specific 3D display system (display device and lenslet array). The complete procedure is illustrated in Figure 2. Note that to optimize the use of the display system's depth range, the display plane needs to be positioned at the center of the reconstructed 3D scene [18]. Additionally, the synthetic elemental image array is loaded onto the display device for 3D InIm display. The position of the virtual pinhole array needs be identical to the position of the lenslet array placed in front of the display device. In addition, the MP POC method not only performs depth rescaling but also mitigates the issue of inaccurate depth information [18]. By employing multiple reference planes (see Figure 2), the MP-POC method enables accurate pixel mapping for objects located at different depths. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Method**} & \multicolumn{3}{c}{**Enhancement**} & \multirow{2}{*}{**Other Limitation**} \\ \cline{2-3}  & **Depth** & & **Field of View** & \\ \hline SPOC [16] & & & Low resolution, mainly for \\ Use of real and virtual fields [17] & X & & static 3D image \\ MP SPOC [18] & X & & \\ MALT [20] & & X & Uniformly scaling, needs \\ IVRT-based scaling [21] & X & X & identical lens array \\ Tunable focus techniques [22; 23; 24] & X & & Need specialized devices \\ Transmissive mirror and & X & X & Need specialized devices \\ semi-transparent mirror [25] & & X & \\ Proposed method in this paper & X & X & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison between methods for optimized integral imaging optical display. In conventional synthetic capture, a single virtual pinhole array is positioned at a specific location. As a result, the depth information recorded by the synthetic elemental images remains unchanged from the original depth range of the scene. To adapt the captured 3D scene to the depth range of a display system, we propose to use multiple virtual pinhole arrays at different positions in the synthetic capture stage. Each virtual pinhole array corresponds to a specific reference plane and records information about it. The multiple elemental image arrays captured through this process are then superimposed to create a new elemental image array. The distance between each reference plane and its corresponding virtual pinhole array in the synthetic capture process is set to match the distance between the image and the display device in the 3D display process. By carefully configuring these parameters (distance between each reference plane and its corresponding virtual pinhole array, \(d\), as shown in Figure 2), the depth of the 3D scene can be effectively rescaled. The proposed depth rescaling method includes the following steps:  
1.