scholarly journals A fast Gabor wavelet transform for high-precision phase retrieval in spectral interferometry

2007 ◽  
Vol 15 (22) ◽  
pp. 14313 ◽  
Author(s):  
J. Bethge ◽  
C. Grebing ◽  
G. Steinmeyer
Keyword(s):  
Wavelet Transform ◽  
High Precision ◽  
Phase Retrieval ◽  
Gabor Wavelet ◽  
Gabor Wavelet Transform ◽  
Spectral Interferometry ◽  
Precision Phase

scholarly journals ISAR Autofocus Imaging Algorithm for Maneuvering Targets Based on Phase Retrieval and Gabor Wavelet Transform

2018 ◽  
Vol 10 (11) ◽  
pp. 1810 ◽  
Author(s):  
Hongyin Shi ◽  
Ting Yang ◽  
Zhijun Qiao
Keyword(s):  
Wavelet Transform ◽  
Motion Compensation ◽  
Rotational Motion ◽  
Phase Retrieval ◽  
Translational Motion ◽  
Gabor Wavelet ◽  
Retrieval Algorithm ◽  
Gabor Wavelet Transform ◽  
Time Frequency ◽  
Maneuvering Target

The imaging issue of a rotating maneuvering target with a large angle and a high translational speed has been a challenging problem in the area of inverse synthetic aperture radar (ISAR) autofocus imaging, in particular when the target has both radial and angular accelerations. In this paper, on the basis of the phase retrieval algorithm and the Gabor wavelet transform (GWT), we propose a new method for phase error correction. The approach first performs the range compression on ISAR raw data to obtain range profiles, and then carries out the GWT transform as the time-frequency analysis tool for the rotational motion compensation (RMC) requirement. The time-varying terms, caused by rotational motion in the Doppler frequency shift, are able to be eliminated at the selected time frame. Furthermore, the processed backscattered signal is transformed to the one in the frequency domain while applying the phase retrieval to run the translational motion compensation (TMC). Phase retrieval plays an important role in range tracking, because the ISAR echo module is not affected by both radial velocity and the acceleration of the target. Finally, after the removal of both the rotational and translational motion errors, the time-invariant Doppler shift is generated, and radar returned signals from the same scatterer are always kept in the same range cell. Therefore, the unwanted motion effects can be removed by applying this approach to have an autofocused ISAR image of the maneuvering target. Furthermore, the method does not need to estimate any motion parameters of the maneuvering target, which has proven to be very effective for an ideal range–Doppler processing. Experimental and simulation results verify the feasibility of this approach.

Down Syndrome Diagnosis Based on Gabor Wavelet Transform

2011 ◽  
Vol 36 (5) ◽  
pp. 3205-3213 ◽  
Author(s):  
Şafak Saraydemir ◽  
Necmi Taşpınar ◽  
Osman Eroğul ◽  
Hülya Kayserili ◽  
Nuriye Dinçkan
Keyword(s):  
Down Syndrome ◽  
Wavelet Transform ◽  
Gabor Wavelet ◽  
Gabor Wavelet Transform ◽  
Syndrome Diagnosis

Content Based Image Retrieval Based on Log Gabor Wavelet Transform

2011 ◽  
Vol 403-408 ◽  
pp. 871-878 ◽  
Author(s):  
Megha Agarwal ◽  
Rudra Prakash Maheshwari
Keyword(s):  
Wavelet Transform ◽  
Image Retrieval ◽  
Retrieval System ◽  
Gabor Wavelet ◽  
Content Based Image Retrieval ◽  
Natural Image ◽  
Feature Descriptor ◽  
Gabor Wavelet Transform ◽  
Log Gabor Wavelet ◽  
Log Gabor

This paper proposes a novel approach of content based image retrieval based on Log Gabor Wavelet Transform (LGWT). It is observed that LGWT better represents an image compared to Gabor Wavelet Transform (GWT). Experimental results illustrate the comparative analysis of proposed retrieval system and the retrieval system based on GWT feature descriptor. It is verified that LGWT based retrieval system improves the average precision and average recall (55.46% and 32.03% respectively) from GWT based retrieval system (50.61% and 31.63% respectively). All the experiments are performed on Corel 1000 natural image database.

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