| PhD Seminar

Name of the Speaker: Mr. Naveen Kumar P (EE19D015)
Guide: Prof. Shanti Bhattacharya
Venue: ESB-244 (Seminar Hall)
Date/Time: 28th February 2025 (Friday), 3:00 PM
Title: Computational techniques for axial resolution improvement and image reconstruction in spectral domain OCT

Abstract :

Fourier-domain Optical Coherence Tomography (FDOCT) is a well-established, high-resolution optical imaging technique used to visualize semi-transparent structures at the micron scale. Despite its advantages in terms of speed and resolution, there are challenges and limitations associated with using Fourier techniques for image reconstruction. In this context, we aim to address some of these limitations by adapting existing linear and non-linear transforms for signal post-processing in spectral-domain OCT.

Initially, we discuss the adaptation of continuous wavelet transforms (CWT) for generating axial scans from raw OCT data, along with its limitations. Subsequently, we present a spatial resolution enhancement technique that leverages the smoothed pseudo Wigner-Ville distribution (SPWVD) for spectral-domain OCT [1]. The proposed technique analyzes the local spectral characteristics of an N-point interferometric signal and generates high-resolution A-scans over N samples rather than N/2, thereby overcoming certain limitations of the FFT method. Experimental results demonstrate a twofold increase in A-scan resolution, effectively resolving closely spaced layers in the sample. Additionally, B-scan images processed with the proposed method exhibit an improved contrast-to-noise ratio compared to the FFT method, enabling high-resolution OCT imaging.

Finally, we discuss some potential applications of spectral-domain OCT in plant health monitoring and the fabric/textile industry