Patent ID: 8295635

Claim:
A method of facilitating elimination of ambient light from an image, comprising: A) obtaining a first image of an object using a first illumination arrangement; B) obtaining a second image of the object using a second illumination arrangement; C) obtaining a dark image without illumination; D) comparing an intensity value of a first pixel in the first image to an intensity value of a corresponding, first pixel in the second image to determine a first minimum intensity value; E) determining if the first minimum intensity value is greater than an intensity value of a corresponding, first pixel in the dark image by greater than a predetermined amount; and F) identifying an ambient intensity value (a) as the first minimum intensity value, if the first minimum intensity value is not greater than the intensity value of the first pixel in the dark image by greater than the predetermined amount, or (b) as the intensity value of the first pixel in the dark image, if the first minimum intensity value is greater than the intensity value of the first pixel in the dark image by greater than the predetermined amount; G) subtracting an intensity value equal to the ambient intensity value from one or both of the first pixel in the first image and the first pixel in the second image; H) comparing an intensity value of a second pixel in the first image to an intensity value of a corresponding, second pixel in the second image to determine a second minimum intensity value; I) determining if the second minimum intensity value is greater than an intensity value of a corresponding, second pixel in the dark image by greater than a second predetermined amount; and J) identifying an ambient intensity value (a) as the second minimum intensity value, if the second minimum intensity value is not greater than the intensity value of the second pixel in the dark image by greater than the predetermined amount, or (b) as the intensity value of the second pixel in the dark image, if the second minimum intensity value is greater than the intensity value of the second pixel in the dark image by greater than a second predetermined amount.