Patent ID: 7158660

Claim:
A method of detecting a structure comprising the steps of: (A) providing a cylindrical illuminator having a light source; (B) shading a target from ambient light with a portion of the illuminator; (C) illuminating the target with the light source; (D) acquiring from the target a plurality of images; (E) reducing background in the plurality of images to generate a second plurality of background-reduced images; (F) reducing noise in the plurality of background-reduced images to generate a noise-reduced image; (G) applying the noise-reduced image a predetermined gains of at least 10 to generate an amplified image; (H) performing steps (A) through (G) with a first wavelength of light to generate a noise-reduced image at a first wavelength to generate an amplified image of the first wavelength; and further comprising repeating steps (A) through (G) with a second wavelength of light to generate an amplified image at the second wavelength that includes noise-subtracted pixels at the second wavelength; and subtracting the amplified image at the first wavelength from the amplified image at the second wavelength to generate a color-subtracted image; and (I) detecting a structure of interest in the color-subtracted image.