Calibration method for quick scanning starts

A method of calibrating a scanner, comprising the steps of:

• performing a full calibration scan;
• performing at least one partial calibration scan;
• comparing the full calibration scan to the partial calibration scan;
• adjusting the gains globally for the full calibration scan when the difference between the partial calibration scan and the full calibration scan is less than a predetermined amount.

A method of calibrating a scanner, comprising the steps of:

• performing a full calibration scan and storing the results as a reference scan;
• performing at least one partial calibration scan without moving the scan head;
• comparing the reference scan to the partial calibration scan;
• performing a PRNU calibration scan and storing the results as a reference scan when the difference between the partial calibration scan and the reference scan is at least equal to a predetermined amount.

A method of calibrating a scanner, comprising the steps of:

• performing a full calibration scan and storing the results as a reference scan;
• performing at least one partial calibration scan without moving the scan head;
• comparing the reference scan to the partial calibration scan;
• adjusting the gains globally for the reference scan when the difference between the partial calibration scan and the reference calibration scan is less than a predetermined amount.

A method of calibrating a scanner, comprising the steps of:

• performing a PRNU calibration scan and storing the results as a reference scan;
• performing at least one partial calibration scan without moving the scan head;
• comparing the reference scan to the partial calibration scan;
• re-performing the PRNU calibration scan when the difference between the partial calibration scan and the reference scan is at least equal to a predetermined amount.