1. A method comprising the steps of: (A) shading a target from ambient light; (B) acquiring from the target a first plurality of images; (C) reducing background in the first plurality of images to generate a first plurality background-reduced images; (D) acquiring from the target a second plurality of images; (E) reducing background in the second plurality of images to generate a second plurality of background-reduced images; (F) reducing noise in the second plurality of background-reduced images to generate a noise-reduced image; (G) multiplying the noise-reduced image to generate an amplified image; and (H) detecting a structure of interest in the amplified image.