Evaluation of handwriting peculiarities utilizing laser speckle contrast imaging

Abstract

Functional handwriting is a process involving various complex interactions between physical, cognitive and sensory systems. Since muscular motion is of a peculiar nature for each person, handwriting properties, such as pencil pressure and speed of writing, can be considered as a unique marker of identity. Moreover, impairments of handwriting in many cases are connected to neurodevelopmental disorders such as attention deficit hyperactivity disorder, developmental coordination disorder, autism spectrum disorders, Parkinson's disease, etc. From this point of view, investigations of handwriting kinematics and pressure can be highly important for both forensic science and medicine. Commonly, the kinematic and pressure features of handwriting are evaluated using a graphics tablet with a stylus or electronic pens. The production of such devices is quite expensive. Therefore, the development of new methods for individual handwriting analysis is an important and current goal. Laser speckle contrast imaging (LSCI) is a powerful method, which is sensitive to both motion and pressure. Since the developed technique requires the use of only a simple laser diode and camera for image acquisition, LSCI is a cost-effective and practical tool for handwriting analysis. In the current letter we present a robust LSCI-based method for handwriting pressure and kinematics evaluation. The introduced approach was validated by an Archimedean spiral writing task.

Interpol questioned documents review 2019–2022

“…Kuznetsov et al evaluated handwriting using laser speckle contrast imaging, a technique sensitive to both pressure and motion [ 51 ]. Laser speckle contrast imaging requires the use of only a simple laser diode and camera for image acquisition and is thus a cost-effective and practical tool for handwriting analysis, and in particular handwriting pressure and kinematics evaluation.…”

Advances in Dynamic Light Scattering Imaging of Blood Flow

“…[45] There are several commercially available LSCI devices widely used for clinical applications. [46,47] LSCI is also effectively used for non-biological applications such as surface roughness evaluation, [48,49] evaluation of handwriting peculiarities, [50] paint drying monitoring, [51] and others. Doppler-based approach was further combined with the optical coherence tomography (OCT), [52] and the resultant Doppler optical coherence tomography (DOCT) allows simultaneous acquisition of high-resolution structural images and flow velocity measurements, [53,54] including flow dynamics in complex vessels.…”

“…[ 45 ] There are several commercially available LSCI devices widely used for clinical applications. [ 46,47 ] LSCI is also effectively used for non‐biological applications such as surface roughness evaluation, [ 48,49 ] evaluation of handwriting peculiarities, [ 50 ] paint drying monitoring, [ 51 ] and others.…”