Patent ID: 8295642
Filing Date: 2012-10-23
Classification: H04N

Abstract:
1. An image processing apparatus comprising: a first line sensor that is arranged in a main-scanning direction and optically reads a first surface of an original, to obtain first line image data; a second line sensor that is arranged in parallel to the first line sensor at a predetermined distance and optically reads a second surface of the original, to obtain second line image data; and a tilt detecting unit that detects a first main-scanning coordinate of a first edge and a second main-scanning coordinate of a second edge from the first line image data, detects a third main-scanning coordinate of a third edge and a fourth main-scanning coordinate of a fourth edge from the second line image data, and detects a tilt of the original with respect to a sub-scanning direction based on detected main-scanning coordinates, wherein the tilt detecting unit calculates a first value by subtracting the third main-scanning coordinate from the first main-scanning coordinate and a second value by subtracting the fourth main-scanning coordinate from the second main-scanning coordinate, and when a difference between the first value and the second value is within a predetermined range, detects the tilt based on the first value, the second value, and the predetermined distance, the first line sensor obtains a plurality of pieces of the first line image data at a plurality of reading times, the second line sensor obtains a plurality of pieces of the second line image data at a plurality of reading times, and the tilt detecting unit calculates the first value for all the pieces of the first line image data, calculates the second value for all the pieces of the second line image data, calculates a representative value of pairs of first values and second values that have differences within the predetermined range among calculated first values and second values, and detects the tilt based on the representative value and the predetermined distance.