Apparatus and methods for coding and storing raster scan images

US4630306A · kind A · utility

Assignee

• NATIONAL RESEARCH DEVELOPMENT CORPORATION · GB

Inventors

• Geoffrey Alec William West · London, GB
• Walter Hill · Mettmann, DE

Key dates

• Filing date: Apr 17, 1984
• Grant date: Dec 16, 1986
• Expiry date: Apr 17, 2004

Classification

• Technology area (CPC G): Physics
• CPC primary: G06T2207/30141
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

In automatically checking circuit boards by raster scanning, it is useful to code and store conductor boundaries for later analysis. Coding time can be reduced by storing an identification of a chain of boundary segments in one of two arrays each time a boundary is detected in a scan line, the identification being stored at an address corresponding to the position of the segment detected. At the same time signals describing the segment are stored in another store at an address related to the identification. When in the next scan line a boundary segment is detected, an address corresponding to its position is used to address the said array and if an identification is found, the new segment is stored in the other store as part of the chain identified. In order to reduce the size of the other store signals describing segments are not stored in areas allocated to chains but in the next vacant location and a RAM stores links between segments.