About Signature RecognitionAt the signature reconnaissance one distinguishes between a dynamic (on line) and static signature reconnaissance (offstage line). While at the dynamic signature reconnaissance the analysed features like acceleration, speed, pressure as well as the sample arisen at the end are measured including the course, merely the geometric sample of the signature is analysed at the static method. The dynamic methods contain unlike the static methods in addition the temporal dimension, must, though the signing be present why one then speaks about online signature examination, too. The online signature reconnaissance uses time-dependent signals of the pen position, the Stiftanpressdrucks and the pen inclination. These signals are measured by a special digitalization board.
As a rule, at the offline signature analysis the user signs with pen and paper, through what merely the document course and the geometric sample can electronically be analysed. Being needed for the static (offstage line) signature analysis merely graphical data of the signature as input data. Signature pads which are used at the static signature reconnaissance are already used as a replacement for credit card pieces of evidence by delivering goods for payments or at acknowledgements of receipt. At the online signature reconnaissance an additional device is needed; it provides considerably more information since they are measuring and evaluating at the speed, pressure and acceleration by a digitalization board.
Quantitative features of the signature are type height, writing breadth, the number and form of bows (like the bow of an l or g) as well as the bow form (convex or concave bow). Also crossroads (e.g. if the t line crosses the vertical line) and junctions (e.g. junction of the vertical P line with his bow) have to be assigned to the quantitative features. Broader parameters for the signature reconnaissance are distinctive beginning and end-points of every stroke as well as interruptions the respective. The full stops of the vowel mutations happening in some documents (for example in German) are also distinctive factors (i, �¤, �¶, �¼). A single stroke (Stroke) stands out due to an uninterrupted contact of the writing pen with the writing surface.
Global parameters like the duration of the complete writing process, the duration of single strokes as well as the middle typing speed are part of the writing dynamics. The temporal functions of the horizontal and vertical writing movement are also classified. In principle, the signature is temporal variant in younger years of life. Signature reconnaissance is generally used merely for the verification because an identification is hardly possible or not sensible due to the high wrong acceptance instalment or too many wrong reconnaissances are carried out. |