Patent ID: 7274486

Claim:
An image data correcting device for correcting a reverse-side projection image that is generated when reading a document from one side of the document, the document having images on both sides thereof, the image data correcting device comprising: a flat detection part configured to detect an intensity difference between first image data corresponding to a part of a predetermined small area and second image data corresponding to the remaining parts of the predetermined small area, and compare the intensity difference with a first predetermined value; an average computing part configured to compare a subtraction value with a second predetermined value, the subtraction value being obtained by subtracting an average value of the first image data and the second image data from the intensity of the first image data; an intensity detection part configured to compare the intensity of the first image data with a third predetermined value; and an intensity changing part configured to change an intensity of the first image data to a predetermined low intensity, when the intensity difference is equal to or less than a first predetermined value and the subtraction value is equal to or less than the second predetermined value and the intensity of the first image data is equal to or less than the third predetermined value, thereby correcting the reverse-side projection image.