Patent ID: 8326081

Claim:
A method for detecting correlation between images, comprising the steps of: obtaining a mean of absolute values of correlation coefficients in a correlation image; determining a Rayleigh parameter from said mean; determining a threshold value based on a desired false detection probability; and registering a detection if a peak one of said correlation coefficients exceeds a product of said threshold and said Rayleigh parameter; wherein said mean is obtained from the relationship ρ _ = 1 MN ⁢ ∑ i = 1 M ⁢ ⁢ ∑ j = 1 N ⁢ ⁢  ρ ⁡ ( i , j )  , where: ρ denotes said mean; M and N are dimensions of said correlation image; and ρ(i,j) denotes said correlation coefficients; and wherein said Rayleigh parameter is determined from the relationship s - ρ _ ⁢ 2 π , where s denotes said Rayleigh parameter.