Grayscale and gamma

CS 248 - Introduction to Computer Graphics
Autumn Quarter, 2003
Marc Levoy
Lecture notes for Tuesday, October 7 (second half of class)

Table of contents:

1. Television chain
2. Graphics chain
3. Quantization for graphics
4. So how many bits?

IV. So how many bits do we need per pixel?

• Synthetic images: 6-8 bits. Some people claim they need more.
  
• Quantization in a linear perceived brightness space: 5 bits looks acceptable (at least for this example)
  
• Scanned/painted images: 5 bits usually ok. Why? Noise breaks up contouring artifacts.
• Antialiased edges: 3 bits suffice! Why? Shorter distance, so contours are compressed.
  This example was also hand drawn, which breaks up contours.