Shape recognition process

In a process of recognizing an object by comparing an objective shape representative of said object with a shape model of the object, the process comprising the steps of:

• A) representing a known shape model in a two dimensional plane as a plurality of first nodal points and a plurality of line segments interconnecting respective pairs of said first nodal points, each line segment including a length characteristic and gradient characteristic;
• B) establishing standard values for the length and gradient characteristics, respectively, of each line segment;
• C) establishing tolerance ranges for the length and gradient characteristics, respectively, of each line segment;
• D) representing said object as a plurality of separate objective shapes each comprised of a row of dots disposed on a two-dimensional plane and having the same number of nodal points as said shape model, said row comprised of a plurality of second nodal points and a plurality of dot segments interconnecting respective pairs of said second nodal points,
• E) separately evaluating each objective shape determined from step D by:
• E1) determining an average spacing of all dots of said dot row from said line segments of said shape model,
• E2) comparing lengths of said dot segments to said tolerance ranges of respective line segment lengths, to determine a length deviation of each dot segment outside of said tolerance range therefor, and summing said length deviations of all dot segments to establish a length deviation sum,
• E3) comparing gradients of said dot segments to said tolerance ranges of respective line segment gradients, to determine a gradient deviation of each dot segment outside of said tolerance range therefor, and summing said gradient deviations of all dot segments to establish a gradient deviation sum,
• E4) summing values of said average spacing, said length deviation sum, and said gradient deviation sum for defining a deviation quantity total, and
• E5) selecting the objective shape having a lowest deviation quantity total for comparison with the shape model.