Patent ID: 6549655
Filing Date: 2003-04-15
Classification: G06K,G06T

Abstract:
An image binarization method comprising the steps of setting a threshold value range for a value concerning a Y value representing brightness of a pixel selected from an image and extracting a pixel with the value concerning the Y value in the image within the threshold value range,wherein when a pixel is selected in the image, the threshold value range is set in a range of adding a predetermined value to the value concerning the Y value of the selected pixel and/or subtracting the predetermined value therefrom, and wherein when after the pixel is selected, a pixel different from that pixel is selected, if the value concerning the Y value of the selected pixel is greater than the value concerning the Y value of the pixel for which the threshold value range is set, between the predetermined value added to the value concerning the Y value of the selected pixel and a lower limit value in the threshold value range, a new threshold value range is set, or if the value concerning the Y value of the selected pixel is smaller than the value concerning the Y value of the pixel for which the threshold value range is set, between the predetermined value subtracted from the value concerning the Y value of the selected pixel and an upper limit value in the threshold value range, a new threshold value range is set.