Abhijit Patil

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A phase-shifting piezo device commonly employed in phase-shifting interferometry exhibits a nonlinear response to applied voltage. Hence, a method for estimation of phase distribution in the presence of nonlinear phase steps is presented. The proposed method compensates for the harmonics present in the intensity fringe, allows the use of arbitrary(More)
BACKGROUND Health care workers' potential exposure to ionizing radiation has increased. Annual radiation exposure limit for the general public per US Nuclear Regulatory Commission is 100 mrem (1 mSv). The whole-body annual occupational radiation exposure limit is 5,000 mrem (50 mSv). Studies have been done to evaluate patient radiation exposure. To date,(More)
A new phase-shifting interferometric technique that uses an unknown phase step is described in which the phase step is determined by use of an algorithm called Probabilistic Global Search Lausanne (PGSL). One of the main sources of error in phase stepping is piezoelectric device (PZT) nonlinearity. The PGSL algorithm identifies the characteristics of the(More)
Recently, a method of finding the spectral samples of non-periodic-finite-rate-of-innovation (NP-FRI) signals using a sum-of-sincs (SoS) sampling kernel was proposed in the literature. In the SoS approach, the kernel is repeated at a rate dependent on the delays of the FRI signal. The number of repetitions depends on both the duration and the delays of(More)
Signal processing methods based on maximum-likelihood theory, discrete chirp Fourier transform, and spectral estimation methods have enabled accurate measurement of phase in phase-shifting interferometry in the presence of nonlinear response of the piezoelectric transducer to the applied voltage. We present the statistical study of these generalized(More)
Organizations be it private or public often collect personal information about an individual who are their customers or clients. The personal information of an individual is private and sensitive which has to be secured from data mining algorithm which an adversary may apply to get access to the private information. In this paper we have consider the(More)
The objective of this paper is to describe an integral approach - based on the use of a super-resolution frequency estimation method - to phase shifting interferometry, starting from phase step estimation to phase evaluation at each point on the object surface. Denoising is also taken into consideration for the case of a signal contaminated with white(More)
A novel generalized approach to phase-shifting interferometry in which phase distribution in an interferogram is evaluated in the presence of nonsinusoidal waveforms and piezoactuator device miscalibration is proposed. The approach is based on the underlying rotational invariance of signal subspaces spanned by two temporally displaced data sets. The(More)
Cramér-Rao Bounds (CRB) for the expected variance in the parameter space were examined for Diffuse Optical Tomography (DOT), to define the lower bound (CRLB) of an ideal system. The results show that the relative standard deviation in the optical parameter estimate follows an inverse quadratic function with respect to signal to noise ratio (SNR). The CRLB(More)
Abdominal tuberculosis is the sixth most common site of extra pulmonary tuberculosis. 1 TB may affect any portion of the GI tract however, in 85% of cases ileocecal region is affected whereas gastroduodenal region is involve only 0.3-2.3% of TB cases of abdominal TB. 2 When gastroduodenal TB is seen without any other lesion of TB in body it is known as(More)