Method of comparing a handwriting with a reference writing

Claim 1

A method of verifying the authenticity of a handwritten sample by use of a reference handwriting comprising the steps of: (a) measuring and recording speed component signals V x and V y of a reference handwriting and a handwritten sample, respectively, where V x and V y are the speed component signals along the abscissa and ordinate of a rectangular coordinates system; (b) dividing each speed component signal of the movement which produced the writing into equal discrete time segments; (c) coordinating the position of each said segment of the handwritten sample with the corresponding segment of the reference writing; (d) tracing vectors from the signals V x and V y corresponding to said discrete tine segments in the plane bounded by coordinate axes OX and OY to produce the hodograph of respectively the reference handwriting and the handwritten sample; (e) selecting position R 1 to R n of the reference writing hodograph and positions M 1 to M n of the handwritten sample hodograph at times t 1 to t n ; (f) calculating the Euclidian distance between the positions of the two hodographs at a given time t, the distance corresponding to the length of the vector MR; (g) dividing the length of the vector MR by the length of the vector OR; (h) comparing the value of the ratio MR/OR to a predetermined acceptance threshold; and (i) repeating steps (e) to (g) for all values of M and R corresponding of values t 1 to t n and tabulating the number of positions at which the value of the ratio MR/OR is acceptable.

Claim 2

A method of verifying the authenticity of a handwritten sample by use of a reference handwriting comprising the steps of: (a) measuring and recording speed component signals V x and V y of a reference handwriting and a handwritten sample, respectively, where V x and V y are the speed component signals along the abscissa and ordinate of a rectangular coordinates system; (b) dividing each speed component signal of the movement which produced the writing into equal discrete time segments; (c) coordinating the position of each said segment of the handwritten sample with the corresponding segment of the reference writing; (d) tracing vectors from the signals V x and V y corresponding to said discrete tine segments in the plane bounded by coordinate axes OX and OY to produce the hodograph of respectively the reference handwriting and the handwritten sample; (e) selecting position R 1 to R n of the reference writing hodograph and positions M 1 to M n of the handwritten sample hodograph at times t 1 to t n ; (f) calculating the Euclidian distance between the positions of the two hodographs at a given time t, the distance corresponding to the length of the vector MR; (g) dividing the length of the vector MR by the length of the vector OR; (h) comparing the value of the ratio MR/OR to a predetermined acceptance threshold; and (i) repeating steps (e) to (g) for all values of M and R corresponding of values t 1 to t n and tabulating the number of positions at which the value of the ratio MR/OR is acceptable.