Extracting Sub-Exposure Images from a Single Capture Through Fourier-based Optical Modulation

TL;DR

This paper presents a Fourier-based optical modulation technique for extracting multiple sub-exposure images from a single capture, enabling applications like high-speed and high-dynamic-range imaging.

Contribution

It introduces a novel frequency division multiplexing inspired coding pattern and a prototype system using LCoS spatial light modulator for pixel-wise exposure coding.

Findings

Successful extraction of sub-exposure images demonstrated

Effective Fourier domain separation achieved with coding masks

Prototype system validates practical feasibility

Abstract

Through pixel-wise optical coding of images during exposure time, it is possible to extract sub-exposure images from a single capture. Such a capability can be used for different purposes, including high-speed imaging, high-dynamic-range imaging and compressed sensing. In this paper, we demonstrate a sub-exposure image extraction method, where the exposure coding pattern is inspired from frequency division multiplexing idea of communication systems. The coding masks modulate sub-exposure images in such a way that they are placed in non-overlapping regions in Fourier domain. The sub-exposure image extraction process involves digital filtering of the captured signal with proper band-pass filters. The prototype imaging system incorporates a Liquid Crystal over Silicon (LCoS) based spatial light modulator synchronized with a camera for pixel-wise exposure coding.