Abstract

A reader for cards having handwritten marks positioned to encode data, is provided with an image recorder for capturing an instantaneous image of the possible mark-bearing area of the card, including the handwritten marks and identification marks printed on the card. A data processor digitizes the data to a matrix of pixels representing grey levels at spaced points in the image. Digital means are provided to locate the identifcation marks and define the expected mark areas of the image field while accounting for positioning error such as skew, and to map the image field into potential mark-bearing areas. A comparator then compares the grey levels at successive pixels or groups of pixels in the mark areas with immediate adjacent pixels or groups, thereby detecting marks by finding contrasting edges. The identification marks printed on the card can be variable in type or position to provide for separate game cards. The reader is adaptable to be reprogrammed for additional games and functions.