Improving image quality of 360-degree viewable holographic display system by applying a speckle reduction technique and a spatial filtering

2018 ◽  
Author(s):  
Yongjun Lim ◽  
Keehoon Hong ◽  
Hayan Kim ◽  
Minsik Park ◽  
Jin-Woong Kim
Keyword(s):  
Image Quality ◽  
Spatial Filtering ◽  
Reduction Technique ◽  
Speckle Reduction ◽  
Display System ◽  
Holographic Display

Evoked Potential Correlates of Display Image Quality

1978 ◽  
Vol 20 (5) ◽  
pp. 589-596 ◽  
Author(s):  
Frank E. Gomer ◽  
Kenneth G. Bish
Keyword(s):  
Image Quality ◽  
Human Brain ◽  
Evoked Potential ◽  
Sensory Stimulation ◽  
Horizontal Resolution ◽  
Future Research ◽  
Display System ◽  
System Parameters ◽  
Gray Shade

The electrical activity generated in the human brain following sensory stimulation can be recorded as voltage differences between electrodes attached to the scalp. These voltage differences are referred to as evoked potentials, and they offer a unique, yet objective, means of assessing visual function. As such, they may link subjective judgments concerning the apparent quality of displayed information with more quantitative measures of perception that are obtained from psychophysical investigations. This report describes the changes in evoked potential amplitude which are exhibited in response to variations in two display system parameters, horizontal resolution and gray shade level. Suggestions are made with respect to future research of this nature.

Restoration and Enhancement of Digitally Reconstructed Holographic Images

2011 ◽  
pp. 105-120
Author(s):  
Rajeev Srivastava
Keyword(s):  
Image Quality ◽  
Image Data ◽  
Speckle Noise ◽  
Zero Order ◽  
Speckle Reduction ◽  
Average Intensity ◽  
Robust Algorithms ◽  
Order Diffraction ◽  
High Pass

Holograms can be reconstructed optically or digitally with the use of computers and other related devices. During the reconstruction phase of a hologram by optical or digital methods, some errors may also be introduced that may degrade the quality of obtained hologram, and may lead to a misinterpretation of the holographic image data, which may not be useful for particular application. The basic common errors are zero-order diffraction and speckle noise. These errors have more undesirable effects in digital than in optical holography because the systems of recording and visualization used in the digital holography are extremely sensitive to them or inclusively increase them. The zero-order diffraction can be removed by using high pass filters with low cut-off frequencies and by subtracting the average intensity of all pixels of the hologram image from the original hologram image. Further, the speckle noise introduced during the formation of digital holographic images, which is multiplicative in nature, reduces the image quality, which may not be suitable for specific applications. As the range of applications get broader, demands toward better image quality increases. Hence, the suppression of noise, higher resolution of the reconstructed images, precise parameter adjustment, and faster, more robust algorithms are the essential issues. In this chapter, the various methods available in literature for enhancement and speckle reduction of digital holographic images have been discussed, and a comparative study of results has been presented.

Influence of limited random-phase of objects on the image quality of 3D holographic display

2017 ◽  
Vol 385 ◽  
pp. 153-159 ◽  
Author(s):  
He Ma ◽  
Juan Liu ◽  
Minqiang Yang ◽  
Xin Li ◽  
Gaolei Xue ◽  
...  
Keyword(s):  
Image Quality ◽  
Random Phase ◽  
Holographic Display

scholarly journals Enhancing the Quality of Sampled Phase-Only Hologram (SPOH) Based on Time-Division Comb Filtering

2020 ◽  
Vol 10 (8) ◽  
pp. 2732
Author(s):  
Peter W. M. Tsang ◽  
Jung-Ping Liu ◽  
Hoson Lam ◽  
Ting-Chung Poon
Keyword(s):  
Digital Holography ◽  
Low Complexity ◽  
Research Area ◽  
Reconstructed Image ◽  
Display System ◽  
Holographic Display ◽  
Image Prior ◽  
Important Research Area ◽  
Time Division

Generation of digital phase-only Fresnel holograms is an important research area in digital holography, as it leads to a substantial simplification of a holographic display system. However, the quality of the reconstructed image of a hologram without the magnitude component is heavily degraded. The problem can be reduced by down-sampling the intensity of an image prior to generating the hologram. The method, referred to as “sampled phase-only hologram” (SPOH) generation, results in reconstructed images that are masked with the pattern of the down-sampling lattice. This paper reports a novel, low complexity method to alleviate this problem through the concept of comb filtering. Results reveal prominent enhancement on the reconstructed image of a SPOH.

3D image quality of 200-inch glasses-free 3D display system

2012 ◽  
Author(s):  
M. Kawakita ◽  
S. Iwasawa ◽  
M. Sakai ◽  
Y. Haino ◽  
M. Sato ◽  
...  
Keyword(s):  
Image Quality ◽  
3D Image ◽  
Display System ◽  
3D Display
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