Patent ID: 7292365

Claim:
A method for estimating an average background value and an average foreground value of an image data formed by a plurality of pixels, the method comprising: selecting a first plurality of pixels forming a first calculation window from the plurality of pixels; determining at least first, second and third statistical moments for the first plurality of pixels; determining an average background value and an average foreground value using the at least first, second and third statistical moments determined for the first plurality of pixels; and outputting results based on the determined statistical moments; wherein determining at least one of average background value and average foreground value is based on the first, second and third statistical moments determined for the first plurality of pixels, determining at least one of average background value and average foreground value beina performed using first approximation techniciue equations a = 1 2 + M 3 2 ⁢ M 3 2 + 4 ⁢ M 2 3 μ 1 = M 1 + M 3 2 ⁢ M 2 - M 3 2 + 4 ⁢ M 2 3 2 ⁢ M 2 μ 2 = M 1 + M 3 2 ⁢ M 2 + M 3 2 + 4 ⁢ M 2 3 2 ⁢ M 2 where M n , represents the n th central moment, “a” represents the relative strength of peaks formed by background and foreground data of the image data, and “μ 1 ” and “μ 1 ” represent mean values of the peaks formed by foreground and background data of the image data.