Patent ID: 6256117
Filing Date: 2001-07-03
Classification: H04N

Abstract:
A method for distinguishing an object to be scanned by a transmissive/reflective dual-mode image scanner as a transmissive object or a reflective object, said transmissive/reflective dual-mode image scanner having a transmitting light source and a reflecting light source, and said method comprising:(a) lighting up either one of said transmitting light source and said reflecting light source as a pre-scan light source;(b) pre-scanning a portion of said object by using said pre-scan light source to obtain a pre-scan image signal;(c) calculating a scanning value of said pre-scan image signal; and(d) distinguishing said object to be said transmissive object or said reflective object according to said scanning value of said pre-scan image signals as to determine which one of said transmitting light source and said reflecting light source will be used for a subsequent scanning operation.