Pixels with Alpha
Alpha channel convention:
- (r, g, b, a) represents a pixel that is a covered by the color C = (r/a, g/a, b/a)
- Color comonents are premultiplied by a
- Can display (r,g,b) values directly
- Closure in composition algebra
What is the meaning of the following?
- (0, 1, 0, 1) = ?
- (0, 1/2, 0, 1) = ?
- (0, 1/2, 0, 1/2) = ?
- (0, 1/2, 0, 0) = ?
Full green, full coverage
Half green, full coverage
Full green, half coverage