Patent ID: 7319805

Claim:
A vision system for a vehicle comprising: a light source generating an illumination beam; a receiver generating a first image signal and a second image signal, at least one of said first image signal and said second image signal being generated in response to at least a reflected portion of said illumination beam; and a controller coupled to said light source and said receiver, said controller generating an image in response to said first image signal and said second image signal; wherein said receiver in generating a first image signal and a second image signal generates an illuminated image signal having pixel intensity values I b and a non-illuminated image signal having pixel intensity values I d ; wherein said controller generates said image in response to a maximum image intensity threshold I b,max and a minimum image intensity threshold I b,min ; and wherein said controller determines pixel intensity values of at least a portion of said image to be approximately equal to I avg - ( I b , max - I b ) ⁢ ( I avg - I b , min ) Δ , where average intensity values I avg are approximately equal to I b + I d 2 and threshold difference Δ is approximately equal to I b,max −I b,min .