High efficient generation of holographic stereograms
based on wavefront recording plane
Xuemei Cao (曹雪梅)
1,
*, Mingxiang Guan (管明祥)
1
, Linzhong Xia (夏林中)
1
,
Xinzhu Sang (桑新柱)
2
, and Zhidong Chen (陈志东)
2
1
School of Electronic and Communication, Shenzhen Institute of Information Technology, Shenzhen 518172, China
2
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and
Telecommunications (BUPT), Beijing 100876, China
*Corresponding author: xuemei_cao88@163.com
Received August 4, 2017; accepted September 22, 2017; posted online October 25, 2017
A computer generated holographic stereogram based on the wavefront recording plane (WRP) is presented. A
WRP closed to the parallax image plane is introduced to record the complex amplitude in a small region for each
point in the parallax image. By using three times of fast Fourier transform (FFT) to execute the Fresnel dif-
fraction calculation between the WRP and the holographic stereogram plane, the object wave contributing to
the hologram pattern can be achieved. The computation complexity of the proposed approach is dramatically
reduced. The results show that the calculation time can be decreased by more than one order of magnitude.
OCIS codes: 090.1760, 090.2870.
doi: 10.3788/COL201715.120901.
Holography technology has attracted considerable atten-
tions since it was first reported by Gabor
[1–3]
. For tradi-
tional optical holography, the holographic recording of
a real object is performed by the interference of waves.
An extreme stability of the optical system and a powerful,
highly coherent laser source is required, whi ch seriously
restricts its application outside the laboratory. Numerous
new holographic techniques for the incoherent illuminated
three-dimensional (3D) scenes were reported. Multiple
viewpoints projection (MVP) holography
[4–6]
and holo-
graphic stereograms
[7–9]
are two important approaches.
For conventional holographic stereograms
[7]
, a hologram
is divided spatially, and each captured parallax image is
coherently recorded on part of the holographic film by
moving a mask over the film. When the hologram film
is illuminated by the same reference wave, the area re-
corded by the parallax image becomes the corresponding
viewpoint. Subsequently, computer generated holographic
stereograms-based parallax image calculation and
diffraction calculation were performed developed
[9–11]
.A
computer generated holographic stereogram is a combina-
tion of an optical holographic stereogram with a com-
puter, which can record and reconstruct vivid 3D
scenes of both virtual and real objects without requiring
a highly stable coherent optical system, which attracted
intense attention. Recently, a simplified calculation
method for computer generated holographic stereograms
based on conventional holographic stereograms from
multi-view images was reported
[12]
. The holographic ster-
eogram was obtained by adding all of the wavefronts
converging to the viewpoints from the parallax images.
Although the parallax images are arranged on the same
plane, they cannot be directly converted into two-
dimensional (2D) wavefronts based on fast Fourier trans-
forms (FFTs). Because, the premise of the 2D wavefront
calculation based on FFTs is that the pixel number of two
2D planes are the same. Since the pixel number of the par-
allax image is not the same as the hologram, the parallax
image cannot be directly converted into 2D wavefronts
based on FFTs. The complex amplitude of the parallax
image should be recorded on the hologram point by point.
Since the hologram is not divided spatially, and each point
of the parallax images contributes to the entire hologram,
the implementation of the calculation process is time
consuming.
Some effective approaches for accelerating hologram
calculation were proposed. Algorithms and hardware im-
plementations for fast generation of computer holograms
were reviewed
[13,14]
. The wavefront recording plane (WRP)
technique was reported to accelerate the calculation of
a computer generated hologram (CGH) which based on
the ray tracing technique
[15]
. Different from traditional
methods
[16,17]
aimed to enhance the generating efficiency
of a hologram from an object, the WRP scheme converted
the object information into a WRP that was placed closed
to the object scene. The object wave emitted from each
object point covered a small area on the WRP. By adding
the contribution of an individual object point, the overall
diffraction pattern on the WRP could be achieved. The
implementation can proceed with a very small amount
of calculation. The hologram can be easily acquired by
Fresnel diffraction between the WRP and holographic
plane. The WRP was successfully deployed for fast gener-
ation and processing of digital holograms
[18–20]
.
Here, the WRP is applied into the generation of a
holographic stereogram. An accelerated calculation
scheme for the generation of holographic stereograms from
a sequence of parallax images and the WRP is presented,
and the calculation time can be greatly reduced by more
than one order of magnitude.
COL 15(12), 120901(2017) CHINESE OPTICS LETTERS December 10, 2017
1671-7694/2017/120901(5) 120901-1 © 2017 Chinese Optics Letters