The SEDRIS Data Representation Model
APPENDIX A - Classes
RGB Colour

Class Name: RGB Colour

Superclass - <Colour Data>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies the actual Red, Green, and Blue data values for a colour defined within the Red Green Blue colour model. These values shall between 0.0 and 1.0, inclusive.

The RGB colour model is probably the best known colour model, and is often visualized as a cube, where the Red, Green, and Blue values define coordinates within the cube.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

This class appears on only one page of the DRM class diagram.

Example

  1. A RGB colour for pure black (rgb_data. red = 0.0, rgb_data. green = 0.0, rgb_data. blue = 0.0).

  2. A RGB colour for bright red (rgb_data. red = 1.0, rgb_data. green = 0.0, rgb_data. blue = 0.0).

FAQs

How can a data consumer who doesn't use the RGB colour model retrieve the colour values in the model he or she does use?

Data consumers who use the CMY, CMYK, or HSV colour models, are in luck. If you tell it to, before you retrieve any colour objects, the SEDRIS Level 0 Read API will change all of the colour objects into <RGB Colour>, <CMY Colour>, or <HSV Colour> instances. And if you need CMYK, ask for CMY, then use the utility functions provided in the DRM API to convert from CMY to CMYK. To tell the SEDRIS Level 0 Read API which colour model you want, after opening the transmittal, before you retrieve any <Colour Data> instances, (or even before you open the transmittal), call the SE_SetColourModel() function, passing in the colour model you want to use.

Also, if you ever have colour data you want to convert from one colour model to another (such as from CMY to RGB), standard utility functions are provided in the DRM API to carry out these data conversions.

Constraints

Composed of (two-way)

Component of (two-way) (inherited)

Inherited Field Elements

This class has no inherited field elements.

Field Elements

SE_RGB_Data rgb_data; (notes)

Notes

Fields Notes


rgb_data

 The rgb_data field specifies the RGB colour coordinate.

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Last updated: July 16, 2004 Copyright © 2004 SEDRIS