8. The digital image processing method as recited in claim 1 , wherein said plurality of formulas are derived using logistic regression.
8. The digital image processing method as recited in claim 1 , wherein said plurality of formulas are derived using logistic regression. 9. The digital image processing method as recited in claim 8 , wherein said step of providing a plurality of formulas includes learning parameters for said plurality of formulas using logistic regression.