Browse Prior Art Database

Overlay Processing with Color Compare Definition

IP.com Disclosure Number: IPCOM000110683D
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Kusano, M: AUTHOR [+2]

Abstract

Disclosed is method for overlay processing with color compare definition between a color image data and a computer graphics data. This is useful for overlaying not only a whole computer graphics data but also a partial computer graphics data on the color image data which is displayed on the CRT screen.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 93% of the total text.

Overlay Processing with Color Compare Definition

       Disclosed is method for overlay processing with color
compare definition between a color image data and a computer graphics
data.  This is useful for overlaying not only a whole computer
graphics data but also a partial computer graphics data on the color
image data which is displayed on the CRT screen.

      This processing is realized with the above block diagram.

      Generally, overlay processing acts between two fields.  One is
a base field 1 for a color image data, such as a photograph or a
TV-type screen.  The other is an overlay field 2 for a color graphics
data, such as a character or a figure.

      For example, the base field consists of 24-bit data, that is,
8-bit Red, 8-bit Green, 8-bit Blue 3.  The overlay field consists of
8-bit data 4.

      The content in the color compare register 5 selects a color of
the compute graphics data which should be overlaid with.

      The content in the color don't care resister 6 enables plural
colors of those computer graphics data to be specified.

      Exclusive NOR gates 7 are used as a comparator.  Each of OR
gates 8 ignores the comparison result.

      An AND gate 9 generates the selection signal which selects the
color image data or the computer graphics data.

      This processing can change the computer graphics data which is
being overlaid with on the color image data only with the contents in
those two resister...