Patent ID: 7420595

Claim:
A method for detecting a flicker noise of an image sensor, comprising the steps of: (a) securing information about images of a first pair of pixel rows by differing exposure points of the first pair of pixel rows having a first exposure time and repeating the image information securing process as changing the exposure points of the first pair of pixel rows; (b) capturing information about images of a second pair of pixel rows by differing exposure points of the second pair of pixel rows having a second exposure time and repeating the image information capturing process as changing the exposure points of the second pair of pixel rows; (c) calculating an average value of the image information for each pixel row of the first and the second pairs of pixel rows in every image information detecting process; (d) ciphering a maximum value and a minimum value among average values for said each pixel row obtained from the step (c); (e) determining a first subtract value by subtracting the minimum value from the maximum value of one pixel row having the first exposure time, deciding a second subtract value by subtracting the minimum value from the maximum value of the other pixel row having the first exposure time, and outputting a smaller one of the first subtract value and the second subtract value as a first minimum subtract value; (f) determining a third subtract value by subtracting the minimum value from the maximum value of one pixel row having the second exposure time, deciding a fourth subtract value by subtracting the minimum value from the maximum value of the other pixel row having the second exposure time, and outputting a smaller one of the third subtract value and the fourth subtract value as a second minimum subtract value; and (g) deciding an exposure time corresponding to the flicker noise by comparing the first minimum subtract value and the second minimum subtract value.