Tomographic single pixel spatial frequency projection imaging

Abstract

Conventional methods for three-dimensional (3D) imaging frequently rely on voxel-by-voxel data acquisition, which restricts the range of specimens in which they can be effectively employed. While advances in imaging technology now permit the routine acquisition of 3D images approaching video rates, there are other limitations to image formation in fluorescent microscopy that prohibit studies in large volume samples, highly scattering media, and dynamic environments. Some approaches to 3D image collection circumvent this need by the use of tomographic imaging, where sub-3D projections are collected at varying illumination angles and reconstructed through an inversion algorithm to compute an estimate of the 3D fluorophore distribution. Many such methods rely on spatially coherent light, and thus prohibit the use of fluorescent light. By employing unique spatio-temporally varying illumination patterns in conjunction with computational imaging approaches to image reconstruction, we show that some limitations of laser scanning and wide-field imaging can be overcome. We outline several approaches that utilize tomographic projections with patterned illumination to collect 3D image data. All three dimensional optical imaging exploits projection of the desired 3D information into a lower-dimensional subspace, and then a full three dimensional object is estimated from these data. We discuss a number of such single pixel strategies that project object information onto a zero-dimensional, usually a power, measurement. Further, we outline computational image reconstruction approaches that enhance the object estimates by employing a forward model for the image formation process.