scholarly journals Improvement of the image quality of random phase-free holography using an iterative method

2015 ◽  
Vol 355 ◽  
pp. 596-601 ◽  
Author(s):  
Tomoyoshi Shimobaba ◽  
Takashi Kakue ◽  
Yutaka Endo ◽  
Ryuji Hirayama ◽  
Daisuke Hiyama ◽  
...  
Keyword(s):  
Image Quality ◽  
Iterative Method ◽  
Random Phase

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

Improvement of image quality of phase-only hologram using random phase-free method

2020 ◽  
Author(s):  
Yumi Yamaguchi ◽  
Yuki Nagahama ◽  
Yota Yamamoto ◽  
Tomoyoshi Shimobaba ◽  
Takashi Kakue ◽  
...  
Keyword(s):  
Image Quality ◽  
Random Phase

scholarly journals Improvement of Image Quality of Phase-Only Hologram using Random Phase-Free Method and Verification by Simulation and Optical Experiments

2020 ◽  
Vol 74 (2) ◽  
pp. 390-394
Author(s):  
Yumi Yamaguchi ◽  
Yuki Nagahama ◽  
Yota Yamamoto ◽  
Tomoyoshi Shimobaba ◽  
Takashi Kakue ◽  
...  
Keyword(s):  
Image Quality ◽  
Random Phase

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Organ doses and subjective image quality of indirect digital panoramic radiography

2001 ◽  
Vol 30 (6) ◽  
pp. 308-313 ◽  
Author(s):  
F Gijbels ◽  
G Sanderink ◽  
C Bou Serhal ◽  
H Pauwels ◽  
R Jacobs
Keyword(s):  
Image Quality ◽  
Panoramic Radiography ◽  
Organ Doses ◽  
Subjective Image Quality ◽  
Digital Panoramic Radiography

Image Quality Enhancing by Efficient Histogram Equalization

2014 ◽  
Vol 2 (2) ◽  
pp. 47-58
Author(s):  
Ismail Sh. Baqer
Keyword(s):  
Image Quality ◽  
Contrast Enhancement ◽  
Mean Squared Error ◽  
Signal To Noise Ratio ◽  
Histogram Equalization ◽  
Gray Level ◽  
Signal To Noise ◽  
Squared Error ◽  
Noise Ratio

A two Level Image Quality enhancement is proposed in this paper. In the first level, Dualistic Sub-Image Histogram Equalization DSIHE method decomposes the original image into two sub-images based on median of original images. The second level deals with spikes shaped noise that may appear in the image after processing. We presents three methods of image enhancement GHE, LHE and proposed DSIHE that improve the visual quality of images. A comparative calculations is being carried out on above mentioned techniques to examine objective and subjective image quality parameters e.g. Peak Signal-to-Noise Ratio PSNR values, entropy H and mean squared error MSE to measure the quality of gray scale enhanced images. For handling gray-level images, convenient Histogram Equalization methods e.g. GHE and LHE tend to change the mean brightness of an image to middle level of the gray-level range limiting their appropriateness for contrast enhancement in consumer electronics such as TV monitors. The DSIHE methods seem to overcome this disadvantage as they tend to preserve both, the brightness and contrast enhancement. Experimental results show that the proposed technique gives better results in terms of Discrete Entropy, Signal to Noise ratio and Mean Squared Error values than the Global and Local histogram-based equalization methods

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