초록 ▼

A portable, hand-held apparatus for capturing a gray scale image of a signature within a box having fiducial marks in the corners. Portions of the image outside the box are trimmed away and the box is oriented and scaled to a standard size and shape. Signature storage requirements are minimized and

A portable, hand-held apparatus for capturing a gray scale image of a signature within a box having fiducial marks in the corners. Portions of the image outside the box are trimmed away and the box is oriented and scaled to a standard size and shape. Signature storage requirements are minimized and signature recognition is facilitated by thresholding the gray scale image and thinning the strokes of the signature to an image width of one pixel.

대표청구항 ▼

[ I claim:] [1.] A method of representing a digital image of a signature, comprising the steps of(a) acquiring a gray scale digital image of said signature, wherein said digital image is comprised of a plurality of rows of pixels and a plurality of columns of pixels, the ith column of said plurality

[ I claim:] [1.] A method of representing a digital image of a signature, comprising the steps of(a) acquiring a gray scale digital image of said signature, wherein said digital image is comprised of a plurality of rows of pixels and a plurality of columns of pixels, the ith column of said plurality of pixels and the jth row of said plurality of pixels being denoted by location [i,j], and the gray scale value of the pixel at location [i,j] being denoted by P[i,j];(b) computing, for at least one location [i,j] in a region of said digital image containing said signature, a plurality of directional second derivatives of P[i,j];(c) selecting from among said second derivatives of P[i,j] the largest magnitude second derivative; and(d) constructing a thresholded digital image of said signature by assigning a first preselected value to a location corresponding to location [i,j] of said digital image if said largest magnitude second derivative is positive and by assigning a second preselected value if said largest magnitude second derivative is not positive.