Patent ID: 6188801
Filing Date: 2001-02-13
Classification: G06K,H04N

Abstract:
A method for automatic image calibration comprising the steps of:a. initializing an index i for X axis and j for Y axis, and a block number;b. reading a pixel on As (i,j), wherein said As (i,j) representing coordinates for a skew image;c. computing an obliquity ratio of said pixel on As (i,j);d. determining if said obliquity ratio divided by the length of said pixel on As (i,j) has a residue less than half the length of said pixel on As (i,j);e. when said residue is smaller than half the length of said pixel on As (i,j), executing first calibration procedure to generate a calibrated pixel for said pixel on As (i,j), wherein said first calibration procedure follows the formula of (A.sub.s (i,j)*((b.sup.2 -a.sub.1 -a.sub.4)/b.sup.2))+(A.sub.s (i,j-1)*(a.sub.2 /b.sup.2))+(A.sub.s (i+1,j)*((a.sub.3 /b.sup.2)), wherein said b representing the length of said pixel on As (i,j) , a.sub.1 representing left calibration portion of said pixel on As (i,j), a.sub.2 representing top calibration portion of said pixel on As (i,j), a.sub.3 representing right calibration portion of said pixel on As (i,j), a.sub.4 representing bottom calibration portion of said pixel on As (i,j);f. when said residue is larger than half the length of said pixel on As (i,j), executing second calibration procedure to generate a calibrated pixel for said pixel on As (i,j) and incrementing said block number by one, wherein said second calibration procedure follows the formula of (A.sub.s (i,j)*((a.sub.4 /b.sup.2))+(A.sub.s (i,j+1)*(a.sub.3 /b.sup.2))+(A(i,j-1)*((a.sub.2 /b.sup.2));g. storing said calibrated pixel in a memory according to said block number;h. increasing said index i and said index j by one; andi. repeating said step (b) and said step (h) until said index i is equal to a predetermined number and reading said calibrated pixels from said memory according said block number.