- A pixel’s brightness is determined by
- Light source (strength, direction, color)
- Surface orientation
- Surface material and albedo
- Reflected light and shadows from surrounding surfaces
- Properties of the sensor
- Pixel intensities are complex to interpret on their own, but the information is often contained in local differences of brightness
- Information is also contained in patterns of intensity variations
- Changes in surface normal
- Texture
- Proximity
- Indents and bumps
- Grooves and creases