1. An imaging circuit, comprising: an image detector; accumulator coupled to the image detector; a focus/defocus mechanism focusing and defocusing an optical image onto the image detector; and a controller operatively connected to the focus/defocus mechanism, wherein the controller controls the focus/defocus mechanism to focus and defocus the optical image onto the image detector to provide focused and defocused images; wherein the controller controls the focus/defocus mechanism to focus the optical image onto the image detector to provide charge carriers of the focused image onto the accumulator, where the accumulator accumulates the charge carriers of the focused image, the controller controls the focus/defocus mechanism to defocus the optical image onto the image detector to provide charge carriers of the defocused image onto the accumulator, where the accumulator subtracts the charge carriers of the defocused image, and the imaging circuit reads out the charge carriers from the accumulator representative of a low pass filtered version of the focused image.