Image transformations on an interactive raster scan or matrix display
US4688181A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1986 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Apr 30, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T11/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An interactive raster-scanned display device has a microprocessor (1) and random access memory (3) which operate to issue instructions to a drawing engine (7) to cause it to load and erase image pel representation in an image buffer (9) in order to control display of images on, or removal of images from a display screen (8) in a conventional manner. A cursor control device (10) enables a user to interact by means of a cursor symbol with images on the screen. In order to reduce the demands imposed on the drawing engine during transformation of images over the screen, the system is configured so that transformation operations are performed using alternative images substituted for the full images. Each alternative image contains considerably less detail to be drawn and erased than the full image it replaces and therefore the operation is more likely to be performed at the rate desired by the user. Thus, complex graphics images containing many vectors are replaced during transformation by simple skeletal or outline drawings. If a large size cross-hair cursor is used for easy indentification on a screen, then this also is replaced by a small symbol whenever it is moved. At the end of th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.