Recognition of documents having copy-prevention

摘要

The method involves laying a photograph on a scanner, scanning with low resolution, and determining the skew angle and position of the photograph. The photograph is then scanned at high resolution, and de-skewed. The presence of absence of one or more micro-points in the high resolution image is detected, and when they are present, the use of the high resolution image is prevented. DETAILED DISCRIPTION - Four further independent claims are provided for methods of detecting copy-protected documents.