Analysis of misfocus effects in compressive optical imaging

In this paper, we investigate the effect of misfocus on the performance of compressive optical imaging. Misfocus occurs either when a thin object sheet is off the focal plane of the optical system, or when the object is extended along the optical axis (3-D imaging). We derive an upper bound on the error in reconstructing a sparse object object, as a function of magnification and misfocus in the optical system. Our theoretical analysis, along with our numerical results, suggest that compressed sensing is robust to misfocus at modest magnification factors. However, at high magnifications factors, which is typical in optical microscopy, compressive imaging performance degrades considerably.