1. A scanning method for checking transparency of a document comprising: a. a single optical sensor to capture both surfaces of said document; b. illuminating any one surface of said document through an illumination source facing said surface; c. imaging of opposite surface of said document wherein an illumination source facing said opposite surface is turned off; d. processing said imaging of opposite surface of said document in a data processor; said processing comprising i. measuring bleed-through in said imaging of opposite surface; ii. contrasting said measured bleed-through with a measured bleed-through of reference image stored in said data processor.
1. A scanning method for checking transparency of a document comprising: a. a single optical sensor to capture both surfaces of said document; b. illuminating any one surface of said document through an illumination source facing said surface; c. imaging of opposite surface of said document wherein an illumination source facing said opposite surface is turned off; d. processing said imaging of opposite surface of said document in a data processor; said processing comprising i. measuring bleed-through in said imaging of opposite surface; ii. contrasting said measured bleed-through with a measured bleed-through of reference image stored in said data processor. 12. The scanning method of claim 1 , wherein said processing of imaging of opposite surface of said document detects the presence of any addition of extra layer or any alteration with 2D barcode imprinted on said one surface of said document.