Use of Graphical Data Display Manager Color Masters to Provide Graphical Interchange Format Output
Original Publication Date: 1996-Jun-01
Included in the Prior Art Database: 2005-Mar-31
A facility to enable IBM's Graphical Data Display Manager (GDDM*) product to support output of color images in Graphical Interchange Format (GIF*) is proposed.
Use of Graphical Data Display Manager Color Masters to
Interchange Format Output
A facility to
enable IBM's Graphical Data Display Manager
(GDDM*) product to support output of color images in Graphical
Interchange Format (GIF*) is proposed.
One way of
achieving this would be to change GDDM internally to
support output of color image and then use a utility to convert this
to GIF output. However, this would entail a substantial change to
GDDM HRIG code which deals with the rastering of Graphics Data Format
(GDF) orders to produce color image output.
To avoid this
problem it is possible to use an existing color
separation table, which outputs image information to eight color
files. A pixel from each color file is combined to give a byte of
color information, which can then be encoded into GIF output.
GDDM has a
function which produces color-separation masters.
This was originally intended for high quality publications printing.
When used with the color-master table ADM00003 this produces ideal
output that can be used to create color image information. The
output is eight files of separated color information in the form of a
binary progression, so a pixel from each color file can be easily
combined to give a byte of color image information. The final color
image will contain a series of bytes where one byte represents the
color (0-255) of a pixel. This color image can then be encoded into
this solution a new GDDM application needs to be
written in any one of the GDDM supported programming languages (e.g.,
C, PLI, REXX). This is far preferable to the alternative of major
changes to GDDM HRIG code.
This application would need to have the following logic: