4. A method as in claim 1 , wherein detecting portrait or landscape orientation based on values computed from strip-based projection profiles comprises: computing a number-of-low-values for vertical document strips and for horizontal document strips; and computing a number-of-valleys from a strip-based horizontal projection profile and from a strip-based vertical projection profile.
4. A method as in claim 1 , wherein detecting portrait or landscape orientation based on values computed from strip-based projection profiles comprises: computing a number-of-low-values for vertical document strips and for horizontal document strips; and computing a number-of-valleys from a strip-based horizontal projection profile and from a strip-based vertical projection profile. 5. A method as in claim 4 , further comprising: converting a number-of-low-values for vertical document strips and for horizontal document strips into a percentage of rows having low values (% RowsLowValues) and a percentage of columns having low values (% ColsLowValues); and logically combining the % RowsLowValues and % ColsLowValues with the number-of-valleys to determine a portrait or landscape document orientation.