To search, Click below search items.


All Published Papers Search Service


An Implementation of Virtual Colored Overlay for Dyslexics


Young Gun Jang


Vol. 9  No. 8  pp. 101-109


A film colored overlay has been used as an assistive device for dyslexics, Recently, several virtual colored overlays which can be used in computer were developed. But existing virtual overlays have some drawbacks which have limited colors and limited control capability over overlapped window by the overlays. Limited colors may prevent optimum color selection and limited control capability can obstruct to transfer keyboard and mouse operation to the overlapped window. In this paper, we implemented an overlay function which controls an overlapped window under the overlay window by using keyboard hooking and tray icon. We propose a method to determine the source color of a virtual overlays by estimating alpha value of alpha blending algorithm through measurement of the chromaticity and transmissivity of film overlays and implemented all colors which we can produce colors by using Intuitive Overlays. Test results of the developed virtual overlay show that all mentioned drawbacks of existing virtual overlays were eliminated and result of WRRT for 3 visual dyslexics using developed overlay shows that reading speed of 2 person are improved by 17.6%, 9.2% respectively, the speed of one person is not improved, but his reading durability is improved from 3 pages to 10 pages.


Dyslexia, Virtual colored overlay, Alpha value estimation, Control an overlapped window, WRRT