scholarly journals Wavelet-based Image Enhancement Techniques for Improving Visual Quality of Ultrasonic Images

2012 ◽  
Vol 39 (17) ◽  
pp. 49-53
Author(s):  
K. Karthikeyan ◽  
C. Chandrasekar
Keyword(s):  
Image Enhancement ◽  
Visual Quality ◽  
Ultrasonic Images

scholarly journals Comparative Study of Different Image Enhancement Techniques

2012 ◽  
Vol 2 (3) ◽  
pp. 131-133
Author(s):  
Saruchi Garg ◽  
Madan Lal
Keyword(s):  
Comparative Study ◽  
Image Enhancement ◽  
Imaging Modality ◽  
Visual Quality ◽  
Low Contrast ◽  
Contrast Image

The main purpose of image enhancement is to bring out detail that is hidden in an image or to increase contrast in a low contrast image. Image enhancement techniques provide a multitude of choices for improving the visual quality of images. Appropriate choice of such techniques is greatly influenced by the imaging modality, task at hand and viewing conditions. This paper analyses the performance of some of existing image enhancement algorithms. The performance of algorithms are evaluated  both qualitatively and quantitatively.

scholarly journals Image Enhancement based on Contrast Enhancement & Fuzzification Histogram Equalization and Comparison with Contrast Enhancement Techniques

2013 ◽  
Vol 7 (2) ◽  
pp. 594-599
Author(s):  
Shubhanshi Gupta ◽  
Ashutosh Gupta ◽  
Gagan Minocha
Keyword(s):  
Fuzzy Logic ◽  
Contrast Enhancement ◽  
Image Enhancement ◽  
Signal To Noise Ratio ◽  
Visual Quality ◽  
Histogram Equalization ◽  
Signal To Noise ◽  
Adaptive Histogram Equalization ◽  
Image Contrast Enhancement

Contrast Enhancement is a technique which comes into the part of Image Enhancement. Contrast Enhancement is used to enhance the visual quality of any captured or other image. Contrast Enhancement can be performed with the help of Histogram equalization (HE). In this technique, the image is collected in the gray scale allocation. The image is then partitioning and applying adaptive Histogram equalization (AHE). Fuzzy logic provides a set of logics which enhance the contrast and visibility of any image. In this technique, the visual quality and the contrast of image will change and then compare these results with previous techniques. The performance of several established image enhancement techniques is presented in terms of different parameters like Absolute mean brightness error (AMBE), Peak signal to noise ratio (PSNR), contrast and Visual quality.

Analysis of color Image Enhancement Using DWT, Wavelet Shrinkageand FHE Methods

2017 ◽  
Vol 7 (8) ◽  
pp. 56
Author(s):  
Ashish Dwivedi ◽  
Nirupma Tiwari
Keyword(s):  
Image Enhancement ◽  
Color Image ◽  
Human Perception ◽  
Histogram Equalization ◽  
Wavelet Shrinkage ◽  
Visual Appearance ◽  
Enhancement Method ◽  
Fuzzy Histogram ◽  
Rgb Image

Image enhancement (IE) is very important in the field where visual appearance of an image is the main. Image enhancement is the process of improving the image in such a way that the resulting or output image is more suitable than the original image for specific task. With the help of image enhancement process the quality of image can be improved to get good quality images so that they can be clear for human perception or for the further analysis done by machines.Image enhancement method enhances the quality, visual appearance, improves clarity of images, removes blurring and noise, increases contrast and reveals details. The aim of this paper is to study and determine limitations of the existing IE techniques. This paper will provide an overview of different IE techniques commonly used. We Applied DWT on original RGB image then we applied FHE (Fuzzy Histogram Equalization) after DWT we have done the wavelet shrinkage on Three bands (LH, HL, HH). After that we fuse the shrinkage image and FHE image together and we get the enhance image.

Enhancing Visual Quality of Multi-view 360 Video Compression Pipeline

2019 ◽  
pp. 135
Author(s):  
Junyoung Yun ◽  
Hong-Chang Shin ◽  
Gwangsoon Lee ◽  
Jong-Il Park
Keyword(s):  
Video Compression ◽  
Visual Quality

scholarly journals ART-UP: A Novel Method for Generating Scanning-Robust Aesthetic QR Codes

2021 ◽  
Vol 17 (1) ◽  
pp. 1-23
Author(s):  
Mingliang Xu ◽  
Qingfeng Li ◽  
Jianwei Niu ◽  
Hao Su ◽  
Xiting Liu ◽  
...  
Keyword(s):  
State Of The Art ◽  
Visual Quality ◽  
Qr Code ◽  
Quick Response ◽  
Estimation Model ◽  
Qr Codes ◽  
Excellent Performance ◽  
Novel Method ◽  
Coarse To Fine

Quick response (QR) codes are usually scanned in different environments, so they must be robust to variations in illumination, scale, coverage, and camera angles. Aesthetic QR codes improve the visual quality, but subtle changes in their appearance may cause scanning failure. In this article, a new method to generate scanning-robust aesthetic QR codes is proposed, which is based on a module-based scanning probability estimation model that can effectively balance the tradeoff between visual quality and scanning robustness. Our method locally adjusts the luminance of each module by estimating the probability of successful sampling. The approach adopts the hierarchical, coarse-to-fine strategy to enhance the visual quality of aesthetic QR codes, which sequentially generate the following three codes: a binary aesthetic QR code, a grayscale aesthetic QR code, and the final color aesthetic QR code. Our approach also can be used to create QR codes with different visual styles by adjusting some initialization parameters. User surveys and decoding experiments were adopted for evaluating our method compared with state-of-the-art algorithms, which indicates that the proposed approach has excellent performance in terms of both visual quality and scanning robustness.

Effect of defocus combined with rotation on the optical performance of trifocal toric IOLs

2021 ◽  
pp. 112067212110021
Author(s):  
Javier Ruiz-Alcocer ◽  
Irene Martínez-Alberquilla ◽  
Amalia Lorente-Velázquez ◽  
José F Alfonso ◽  
David Madrid-Costa
Keyword(s):  
Visual Quality ◽  
Optical Quality ◽  
Refractive Errors ◽  
Focal Points ◽  
Modulation Transfer ◽  
Optical Analysis ◽  
Toric Intraocular Lens ◽  
Toric Iols ◽  
Reference Situation

Purpose: To objectively analyze the optical quality of the FineVision Toric intraocular lens (IOL) with two cylinder powers when different combinations of rotations and residual refractive errors are induced. Methods: This study assessed the FineVision Toric IOL with two different cylinder powers: 1.5 and 3.0 diopters (D). Three different rotation positions were considered: centered, 5° and 10° rotated. An optical bench (PMTF) was used for optical analysis. The optical quality of the IOLs was calculated by the modulation transfer function (MTF) at five different focal points (0.0, 0.25, 0.50, 0.75, and 1.00 D). Results: The MTF averaged value of the reference situation was 38.58 and 37.74 for 1.5 and 3.0 D of cylinder, respectively. For the 1.5 D cylinder, the combination of 5° of rotation with a defocus of 0.25, 0.50, 0.75, and 1.0 D induced a decrease on the MTF of 12.39, 19.94, 23.43, 24.23 units, respectively. When induced rotation was 10°, the MTF decrease was 17.26, 23.40, 24.33, 24.48 units, respectively. For the 3.0 D cylinder, the combination of 5° with 0.25, 0.50, 0.75, and 1.0 D of defocus, induced a decrease on the MTF of 12.51, 18.97, 22.36, 22.48 units, respectively. When induced rotation was 10°, the MTF decrease was: 18.42, 21.57, 23.08, and 23.61 units, respectively. Conclusion: For both FineVision Toric IOLs there is a certain optical tolerance to rotations up to 5° or residual refractive errors up to 0.25 D. Situations over these limits and their combination would affect the visual quality of patients implanted with these trifocal toric IOLs.

scholarly journals A New Instrument for Evaluating the Visual Quality of Air

1967 ◽  
Vol 17 (7) ◽  
pp. 467-469 ◽  
Author(s):  
Norman C. Ahlquist ◽  
Robert J. Charlson
Keyword(s):  
Visual Quality ◽  
New Instrument

K out of N Secret Sharing Scheme for Multiple Color Images with Steganography and Authentication

2016 ◽  
Vol 16 (02) ◽  
pp. 1650010 ◽  
Author(s):  
P. Mohamed Fathimal ◽  
P. Arockia Jansi Rani
Keyword(s):  
Secret Sharing ◽  
Visual Quality ◽  
Color Images ◽  
Pixel Expansion ◽  
Image Sharing ◽  
Digital Ecosystem ◽  
Sharing Scheme ◽  
Text Steganography ◽  
Key Aspects

With our lives trundling toward a fully-digital ecosystem in break-neck speed, today’s encryption and cryptography are facing the challenge of ensuring security and future-readiness of our transactions. When such transactions involve multiple hands, transmission of such data in discrete and recoverable parts (secret shares) guarantees confidentiality. This paper’s objective is to present a foolproof way of multiple secret sharing, eliminating issues such as half-toning and degradation of visual quality of the recovered images. This [Formula: see text] out of [Formula: see text] steganography and authenticated image sharing (SAIS) scheme for multiple color images generates [Formula: see text] relevant shares with the ability to reconstruct the secret images using [Formula: see text] shares and facility to find out any move for appropriation of share cover images. The key aspects of this proposed scheme is to use simple Boolean and arithmetic operations with reduction of computational complexity from [Formula: see text] to [Formula: see text] and to share multiple images without any pixel expansion.

scholarly journals Aspheric Intraocular Lenses Implantation for Cataract Patients with Extreme Myopia

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Yanwen Fang ◽  
Yi Lu ◽  
Aizhu Miao ◽  
Yi Luo
Keyword(s):  
Contrast Sensitivity ◽  
Visual Quality ◽  
Intraocular Lenses ◽  
Wavefront Aberrations ◽  
Spatial Frequencies ◽  
Aspheric Iol ◽  
Significant Difference ◽  
Composite Scores ◽  
Cataract Patients

Objective. To evaluate the postoperative visual quality of cataract patients with extreme myopia after implantation of aspheric intraocular lenses (IOLs). Methods. Thirty-three eyes were enrolled in this prospectivestudy. Eighteen eyes with an axial length longer than 28 mm were included in the extreme myopia group, and the other 15 eyes were included in the nonextreme myopia group. Phacoemulsification and aspheric IOL implantation were performed. Six months after cataract surgery, best-corrected visual acuity (BCVA), contrast sensitivity, and wavefront aberrations were measured, and subjective visual quality was assessed. Results. The BCVA improved significantly after surgery for both groups, and patients in the nonextreme myopia group achieved better postoperative BCVA due to better retinal status of the eyes. The evaluation of contrast sensitivity without glare was the same in both groups, whereas patients in the nonextreme myopia group performed better at intermediate spatial frequencies under glare conditions. The two groups did not show a significant difference in high-order aberrations. With regard to subjective visual quality, the composite scores of both groups did not differ significantly. Conclusions. Aspheric IOLs provided good visual outcomes in cataract patients with extreme myopia. These patients should undergo careful evaluation to determine the maculopathy severity level before surgery.

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