Digital Image Fundamentals

1
Digital Image Fundamentals

• Human visual system
• A simple image model
• Sampling and quantization
• Color models and Color imaging

2
Human Visual System

• Elements of visual perception

3
Human Visual System

• Brightness adaptation
• Brightness discrimination
• Weber ratio
• Mach band pattern
• Simultaneous contrast

4
A simple image model

• Two-dimensional light-intensity function
• Illumination
• Reflectance
• Typical ranges of illumination
• Typical ranges of reflectance
• Gray-level of monochrome images
• Grayscale

5
Sampling

• Digitization of the spatial coordinates

6
Quantization

• Digitization of the light intensity

7
Sampling and Quantization

• How many samples to take?
• How many gray-levels to store?

8
Sampling and Quantization

• Non-uniform sampling
• Non-uniform quantization

9
Basic relationships between pixels

• Neighbors
• Connectivity

10
Color Imaging

• Light

11
Color Imaging

• Trichromacy and human color vision

12
Color Imaging

• Color image formation (acquisition)

13
Color Imaging

• Color models

14
Color Imaging

• Color models