SIGGRAPH 98 - Course 25

Orlando, July 20, 1998 (morning)
Half-day course

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Color Image Coding

Computers have been used to generate synthetic images since the first SIGGRAPH, and to generate color images for nearly that long. But only recently has it become practical to create and reproduce digital images with predictable, accurate color. This course introduces the science behind image digitization and color reproduction in computer graphics and video. A key aspect of obtaining accurate color is understanding the objective meaning of RGB codes: The interpretation of a particular RGB code by one system may not match the interpretation of the same RGB code by a different system. We describe how color information is coded into RGB, then we detail the transformations among various color image coding systems.

Prerequisites

You should be comfortable with mathematics. You should have experience in designing or implementing hardware or software that processes color images; alternatively, you should be very experienced in manipulating digital imagery.

Topics beyond the prerequisites

Much information is available about color specification systems such as CIE XYZ, L*a*b*, L*u*v*, HLS, HSB, and HVC, but the coding of color image data has a different set of constraints than color specification. We describe how linear-light intensity representations are transformed into the nonlinear R'G'B' system, and then into the Y'C_BC_R representations (4:2:2, 4:1:1, and 4:2:0) used in studio video, DVC, JPEG, and MPEG. We review the Y'UV and Y'IQ derivatives of Y'C_BC_R.

You may also be interested in the companion course, Color management: Technology & implementation.

If your interest in color coding is associated with video, you may also be interested in the course, Digital video: Algorithms & interfaces.

Registration

Registration and other information is available at the SIGGRAPH 98 courses page.

Charles Poynton - Courses & seminars
1998-02-10