Intensity-based dynamic speckle method using JPEG and JPEG2000 compression

2021 ◽  
Author(s):  
Elena Stoykova ◽  
Blaga Blagoeva ◽  
Nataliya Berberova ◽  
Mikhail Levchenko ◽  
Dimana Nazarova ◽  
...  
Keyword(s):  
Jpeg2000 Compression ◽  
Dynamic Speckle

Secure Watermarking using Diophantine Equations for Authentication and Recovery

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Jayashree Nair ◽  
T. Padma
Keyword(s):  
Diophantine Equation ◽  
Diophantine Equations ◽  
Jpeg Compression ◽  
Authentication Scheme ◽  
Original Image ◽  
Invariant Features ◽  
Jpeg2000 Compression ◽  
Frequency Properties ◽  
Visual Authentication

This paper describes an authentication scheme that uses Diophantine equations based generation of the secret locations to embed the authentication and recovery watermark in the DWT sub-bands. The security lies in the difficulty of finding a solution to the Diophantine equation. The scheme uses the content invariant features of the image as a self-authenticating watermark and a quantized down sampled approximation of the original image as a recovery watermark for visual authentication, both embedded securely using secret locations generated from solution of the Diophantine equations formed from the PQ sequences. The scheme is mildly robust to Jpeg compression and highly robust to Jpeg2000 compression. The scheme also ensures highly imperceptible watermarked images as the spatio –frequency properties of DWT are utilized to embed the dual watermarks.

scholarly journals Dynamic Speckle Illumination Digital Holographic Microscopy by Doubly Scattered System

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 276
Author(s):  
Yun Liu ◽  
Peihua Bu ◽  
Mingxing Jiao ◽  
Junhong Xing ◽  
Ke Kou ◽  
...  
Keyword(s):  
Time Correlation ◽  
Digital Holographic Microscopy ◽  
Laser Source ◽  
Speckle Reduction ◽  
Single Shot ◽  
Coherent Noise ◽  
Real Time Measurement ◽  
Dynamic Speckle ◽  
Holographic Microscopy ◽  
Speckle Suppression

The coherent noise always exists in digital holographic microscopy due to the laser source, degrading the image quality. A method of speckle suppression using the dynamic speckle illumination, produced by double-moving diffusers, is presented in digital holographic microscopy. The space–time correlation functions are theoretically analyzed from the statistics distribution in the doubly and singly scattered system, respectively. The configuration of double-moving diffusers is demonstrated to have better performance in speckle suppression compared with the single diffuser and moving-static double diffusers cases. The experiment results verify the feasibility of the approach. The presented approach only requires a single shot interferogram to realize the speckle reduction, accordingly it has the potential application in real-time measurement.

scholarly journals Dynamic speckle multiplexing scheme in volume holographic data storage and its realization

2003 ◽  
Vol 11 (4) ◽  
pp. 366 ◽  
Author(s):  
Qingsheng He ◽  
Jinnan Wang ◽  
Jiangang Wang ◽  
Minxian Woo ◽  
Guofan Jin
Keyword(s):  
Data Storage ◽  
Holographic Data Storage ◽  
Dynamic Speckle ◽  
Volume Holographic Data Storage

CHARACTERIZING DYNAMIC SPECKLE TIME SERIES WITH THE HURST COEFFICIENT CONCEPT

Fractals ◽  
2004 ◽  
Vol 12 (03) ◽  
pp. 319-329 ◽  
Author(s):  
L. I. PASSONI ◽  
H. RABAL ◽  
C. M. ARIZMENDI
Keyword(s):  
Speckle Pattern ◽  
Time History ◽  
Speckle Interferometry ◽  
Active Materials ◽  
Laser Illumination ◽  
Corn Seed ◽  
Dynamic Speckle ◽  
Hurst Coefficient ◽  
History Of ◽  
Living Tissues

We propose in this work a dynamic speckle descriptor based on a Hurst wavelet estimator. The dynamic speckle or biospeckle is a phenomenon produced by laser illumination of active materials, such as biological tissue or the drying process of paint. Dynamic speckle interferometry is a useful technique for assessing the time evolution of surfaces as also to segment the loci of different activity in living tissues. Considering previous biospeckle characterization based on the autocorrelation function and its relation with the Hurst coefficient, a wavelet-based estimator is proposed as a feature extraction of the dynamic speckle characteristic. Encouraging results of the descriptor performance are obtained via three different experiments: a time history of speckle pattern applied to the drying of painting, segmenting regions in whole field image applied to the viability test of a corn seed and also to the bruising in fruits.

Dynamic speckle processing using wavelets based entropy

2005 ◽  
Vol 246 (1-3) ◽  
pp. 219-228 ◽  
Author(s):  
I. Passoni ◽  
A. Dai Pra ◽  
H. Rabal ◽  
M. Trivi ◽  
R. Arizaga
Keyword(s):  
Dynamic Speckle

A numerical model for dynamic speckle and its application to the analysis of temporally evolving processes

2006 ◽  
Author(s):  
Héctor Rabal ◽  
Marcelo Trivi ◽  
Ricardo Arizaga ◽  
Alejandro Federico ◽  
Gustavo E. Galizzi ◽  
...  
Keyword(s):  
Numerical Model ◽  
Dynamic Speckle
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