Image display apparatus

• Main Author: RICHARDS, NORMAN DENNIS
• Format: Patent
• Language: English; French; German
• Published: 02.03.1994
• Edition: 5
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

Pixel information for image display is available in a mass memory as two sets of digital data of which, a first set represents values for the difference between pixel component values for an image of a given (enchanced) resolution and pixel component values for an image of lower resolution of the same pixel density, and a second set represents a lesser number of pixel component values for the lower resolution image but of reduce pixel density. In order to obtain pixel component values for displaying the enhanced resolution image, the first and second set of digital data are decoded and the pixel component values from the second set are expanded by interpolation and then added to the difference values from the first set. Different embodiments of display apparatus are described in which a display generator performs these operations in real time for a raster scan display device. This enables the two sets of digital data to be transferred from the mass memory to a display memory of the display apparatus without being recoded, thereby achieving more efficient use of the display memory. Figure 6 gives a general layout of the display apparatus.