Image analysis applied to two-dimensional hand-drawn geometrical figures for the monitoring of visuoperceptual dysfunction

The authors describe a study of the automated analysis of hand-copied two-dimensional line drawings to develop a technique which utilises automatic image analysis to overcome some of these difficulties. The task domains considered require the specification of target line drawings which are to be copied freehand by the subject, and these tasks must be chosen to offer an appropriate degree of cognitive and motor difficulty. A particular task domain of interest has been the generation of a sketch of a regular geometric shape such as 3-dimensional cube, a target which both imposes a requirement of reasonably complex visual-motor coordination and which can exercise cognitive skills relating to the perception of perspective and three-dimensional conceptualisation. The physical infrastructure for a prototype system is based on the use of an IBM or compatible personal computer and a high resolution graphics tablet. The purpose of the graphics tablet is to provide a peripheral through which the two-dimensional drawing of a subject in a figure copying task can be digitised and transmitted to the computer as a set of (x-y) coordinates