Patent ID: 6373983
Filing Date: 2002-04-16
Classification: G06T,H04N

Abstract:
A method for detecting missing lines occurred in a scanned image generated by an optical scanner according to a standard deviation value, a slanting line segment is used to reflect the occurrence of missing lines, comprises the steps of:a. initializing a first index for X axis, a second index for Y axis, a shift index and a counter, and said first index denoted as i, said second index as j, said shift index as k; b. predetermining an error tolerance value; c. setting a starting pixel (Xi,Yj) of said image for gray-level comparison, said starting pixel having gray levels closest to a median value of predetermined highest gray levels; d. comparing the gray levels of said starting pixel (Xi,Yj) and pixel on (Xiâˆ’1,Yj+1), and then outputting a first comparison result; e. when said first comparison result is smaller than said predetermined error tolerance value, shifting said index i by k+1 and increasing said index j by one, and then executing said step (d); f. when said first comparison result is larger than said predetermined error tolerance, comparing the gray levels of the pixels on (Xi,Yj), (Xiâˆ’k,Yj+1) and (Xi(k+1),Yj+1) and outputting a second comparison result; g. determining if said second comparison result is correspondent to a predetermined comparison condition; h. increasing said counter by one, and executing said step (d) when said second comparison result is correspondent to said predetermined comparison condition,; i. marking pixels on (Xiâˆ’k,Yj+1) and (Xi(k+1),Yj+1), increasing said counter by one, and executing said step (f) when said second comparison result is not correspondent to said predetermined comparison condition; and j. when said j plus one equals to a length of said slanting line segment, outputting a detection result.