Multiple-view compressed-sensing ultrafast photography (mv-cup)

Abstract

A system and method for compressed-sensing ultrafast photography for two-dimensional dynamic imaging is disclosed. The system and method may capture non-repetitive time-evolving events at up to about 100 billion frames per second. In an aspect, a digital micromirror device (DMD) may be added as the spatial encoding module. By using the DMD and applying the CUP reconstruction algorithm, a conventional 1D streak camera may be transformed to a 2D ultrafast imaging device. The resultant system may capture a single, non-repetitive event at up to 100 billion frames per second with appreciable sequence depths (up to about 350 frames per acquisition). In another aspect, a dichroic mirror may be used to separate signals into two color channels, and may further expand CUP's functionality into the realm of four-dimensional x, y, λ, t ultrafast imaging, maximizing the information content that may be simultaneously acquired from a single instrument. On the basis of compressed sensing (CS), CUP may encode the spatial domain with a pseudo-random binary pattern, followed by a shearing operation in the temporal domain, performed using a streak camera with a fully opened entrance slit. This encoded, sheared three-dimensional (3D) x, y, t scene may then be measured by a 2D detector array, such as a CCD, within a single snapshot. The image reconstruction process follows a strategy similar to CS-based image restoration—iteratively estimating a solution that minimizes an objective function. However, unlike CS-based image restoration algorithms, which target the reconstruction of a 2D x, y image, CUP reconstruction recovers a 3D x, y, t movie by applying regularization over both the spatial domain and the temporal domain.