Simplified digital content generation based on an inverse-directed propagation algorithm for holographic stereogram printing

Abstract

Holographic stereogram (HS) printing requires extensive memory capacity and long computation time during perspective acquisition and implementation of the pixel re-arrangement algorithm. Hogels contain very weak depth information of the object. We propose a HS printing system that uses simplified digital content generation based on the inverse-directed propagation (IDP) algorithm for hogel generation. Specifically, the IDP algorithm generates an array of hogels using a simple process that acquires the full three-dimensional (3D) information of the object, including parallax, depth, color, and shading, via a computer-generated integral imaging technique. This technique requires a short computation time and is capable of accounting for occlusion and accommodation effects of the object points via the IDP algorithm. Parallel computing is utilized to produce a high-resolution hologram based on the properties of independent hogels. To demonstrate the proposed approach, optical experiments are conducted in which the natural 3D visualizations of real and virtual objects are printed on holographic material. Experimental results demonstrate the simplified computation involved in content generation using the proposed IDP-based HS printing system and the improved image quality of the holograms.

Simplified digital content generation using single-shot depth estimation for full-color holographic printing system

“…Then 3D object information is obtained according to the depth information that estimated using CNN-based pre-trained model and captured 2D high-resolution image. After that, the sub-holograms (hogels) array pickup is applied by using the simple and fast IDP algorithm [13] based on computer-generated integral imaging (CGII) from acquired 3D scene data. Then, the red, green, and blue (RGB) channels of each hogel are resized according to the used RGB laser beam wavelengths to remove chromatic dispersion error in full-color hologram by following Eq.…”

“…In addition, a digital holographic printing that records a color image hologram with a full parallax of 120° is presented [11]. Also, an HS printing system with simple and fast computation for digital content generation using the inverse-directed propagation (IDP) algorithm is proposed [13]. Moreover, depth estimation is one of the effective methods that is utilized in several applications such as 3D imaging and scanning, background removal and separation, and 3D object rendering.…”

High-Quality 3D Visualization System for Light-Field Microscopy with Fine-Scale Shape Measurement through Accurate 3D Surface Data

“…A high-quality 3D model is generated by obtaining the RGB-D point cloud object from the depth map, including the 3D surface and the 2D image, including color and texture. After that, the EIA is generated using the 3D object with high-quality, as shown in Figure 6 c, by applying the DRC method [ 30 ]. This is based on the backward rendering of computer-generated integral imaging, where depth and color information of the 3D model is obtained according to the layered depth data and the main parameters of a virtual lens array and display device are given by the user.…”

Color optimization of a full-color holographic stereogram printing system using a single SLM based on iterative exposure control

“…Moreover, several HS methods based on InIm techniques are presented by using fast Fourier transform (FFT) calculations to convert an elemental image (EI) into a hogel; this improves HS image quality [8,9]. Also, an HS printing system with simplified fast digital content generation using the inverse-directed propagation (IDP) algorithm has been applied for direct HS printing [10]. Moreover, there are several articles for full-color holographic printing and those are especially focused on wavefront printing.…”