  Digital two-dimensional (2D) spatial sampling devices (such as charge-coupled
device) have been widely used in various imaging systems, especially in
computational imaging systems. However, the undersampling of digital sampling
devices is a problem that limits the resolution of the acquired images. In this
study, we present a synthetic sampling imaging (SSI) concept to solve the
undersampling problem. It combines the structured illumination system and
conventional 2D image detection system to simultaneously sample the specimen
from the illumination and the detection sides. Then, we synthesize the
illumination sampling rate and the detection sampling rate to reconstruct a
high sampling rate image. The concept of the proposed SSI is demonstrated by an
example of microscopy. Experimental results confirm that the proposed method
can double the sampling resolution of the microscope. The synthetic sampling
scheme, where the sampling task is shared by the illumination and detection
sides, provides insight for resolving the undersampling problem of the digital
imaging system.
