SIGGRAPH 2004 -
Course 2SIGGRAPH 2004 -
Course 2Organizer: Charles Poynton
Presenters: | Charles Poynton Garrett M. Johnson, Munsell Color Science Lab at RIT |
This course introduces the science behind image digitization, tone reproduction, and color reproduction in computer generated imagery (CGI), HDTV, and digital cinema (D-cinema). We detail how color is represented and processed as images are transferred between these domains. We detail the different forms of nonlinear coding ("gamma") used in CGI, HDTV, and D-cinema. We explain why one system's RGB does not necessarily match the RGB of another system. We explain color specification systems such as CIE XYZ, L*a*b*, L*u*v*, HLS, HSB, and HVC. We describe why the coding of color image data has a different set of constraints than color specification, and we detail color image coding systems such as RGB, R'G'B', CMY, Y'CBCR, and DPX/Cineon. We explain color measurement instruments such as densitometers and colorimeters, and we explain monitor calibration. We explain how color management technology works, and how it is currently being used in motion picture film production (both animation and live action).
Reproducing the tristimulus numbers of classical color science only reproduces colors accurately in an identical viewing environment. If the viewing situation changes, color is not completely described by numbers. In applying color science to image reproduction, we wish to reproduce images in environments where angular subtense, background, surround, and ambient illumination may differ from the conditions at image origination. Recent advances in color appearance modelling allow us to quantify the alterations necessary to reproduce color appearance in different conditions. We will introduce the theory and standards of color appearance models. We will then describe the application of color science and color appearance models to commercial motion imaging in computer graphics, video, HDTV, and D-cinema.
Prerequisites
This course is suitable for people who have no fear of mathematics and who are experienced in creating or manipulating digital images in CG and/or video. We assume some familiarity with color color image coding, perhaps gained through attending a color course at a previous SIGGRAPH.
Registration
Registration and other information is available at the SIGGRAPH 2004 courses page, or the page specific to Course 2.
Charles Poynton - Courses & seminars
2004-03-04