Patent ID: 9118785
Filing Date: 2015-08-25
Classification: H04N

Abstract:
1. A method of scanning a physical medium by an image scanner comprising a first image sensor having a plurality of image sensor elements that provide image signals recorded at a first area of the physical medium, and a first light source associated with said first image sensor, said method comprising: guiding light emitted from said first light source towards a first group of image sensor element(s) positioned in a first end of said first image sensor, recording a first light calibration value using said first group of image sensor element(s) indicative of a light intensity, at a first end of the first image sensor, of the light generated by the first light source; repeating the guiding and the recording using a second group of image sensor element(s) positioned in a second end of said first image sensor, thus resulting in a second light calibration value indicative of a light intensity, at a second end of the first image sensor, of the light generated by the first light source; and generating a first compensation signal for image sensor elements positioned between said first and said second group of image sensor element(s) by processing said first and said second light calibration value together; compensating said image signals provided by said first image sensor using said first compensation signal for variations in light intensity of the first light source and sensitivities of the image sensor elements of the first image sensor.