Patent Document ID: 20090297021
Application ID: 12386814
Patent Status: 0

Claim One:
1. A method of transforming a plurality of training images into a synthetic discriminant function (SDF) reference image for use with an optical pattern recognition system, the method comprising: (a) constructing a synthesized weighted average function of the training images according to: r SDF ( x , y ) = ∑ i = 1 N a i r i ( x , y ) ∑ i = 1 N a i wherein a i represents a coefficient for each training image; (b) initializing the a i coefficients to unity; (c) calculating an SDF reference image for each iteration; (d) creating a correlation matrix by comparing each training image with the current SDF reference image according to: 
 corr i k ( x,y )= r SDF k ( x,y )⊕ r i ( x,y ) where k is the iteration number and ⊕ represents the correlation operation; (e) determining the correlation peak intensities for each training image; (f) determining an error value based on the maximum correlation peak intensity and minimum correlation peak intensity among the training images according to: ξ k = ( C ma x k - C m i n k ) C m ax k where ξ k is the error calculated in the k-th iteration and C max k and C min k are the maximum and the minimum correlation peaks computed in the k-th iteration; and (g) if the error value is not within a predetermined threshold, then (h) updating the a i coefficients for the next iteration according to: 
 α i k+1 =α i k +( C max k −C i k )δ where δ is a relaxation factor that determines the rate of changing the coefficients from one iteration to the next; and (i) repeating steps (c) through (g) until the error value is within the predefined threshold.