TABLE OF CONTENTS This is a plea for precise terminology. The notation YUV, and the term luminance, are widespread in digital video. In truth, digital video almost never uses Y?UV color difference components, and never directly represents the luminance of color science. The common terms are almost always wrong. This note explains why. I urge video engineers and computer graphics specialists to use the correct terms, almost always Y ?C B C R and luma.
I'll demonstrate by analogy why it is important to use correct terms. Next time you're waiting in line for a bus, ask the person next to you in line what building material is used to construct a sidewalk. Chances are that person will answer, "cement."
The correct answer is concrete. Cement is calcined lime and clay, in the form of a fine, gray powder. Cement is one ingredient of concrete; the other ingredients are sand, gravel, and water.
In an everyday situation, you need not be precise about which of these terms are used: If you refer to a sidewalk as being constructed of "cement," people will know what you mean. Lay people are not confused by the term cement. Interestingly, experts are not confused either. If a construction superintendent yells out to his foreman, "Get me 500 pounds of cement!" the foreman understands immediately from context...
