Digital Image Processing

Study Notes

A digital image is a two-dimensional function, F(x,y), where x and y are spatial coordinates, and the amplitude of F at any pair of coordinates (x,y) is called the intensity of that image at that point.
Common image formats include:
- 1 sample per point (B&W or Grayscale)
- 3 samples per point (Red, Green, and Blue)

Image Enhancement: improve quality, remove noise, etc.
The Hubble Telescope: used image processing techniques to fix incorrect mirror images
Medicine: take slice from MRI scan of canine heart, and find boundaries between types of tissue
Geographic Information Systems (GIS): use digital image processing techniques to manipulate satellite imagery
Industrial Inspection: use machines to inspect products, reducing human error
Human Computer Interaction (HCI): use digital image processing to make human-computer interfaces more natural, e.g. face recognition and gesture recognition

The amount of light entering the eye is controlled by the pupil
The light is focused on the retina, where receptors convert it into nerve signals that pass to the brain
Elements of visual perception:
- Cones: 6-7 million in each eye, involved in photopic or bright-light vision, highly sensitive to color
- Rods: 75-150 million, involved in scotopic or dim-light vision, not involved in color vision

Simultaneous Contrast: a region's perceived brightness does not depend simply on its intensity
Optical Illusions: the eye fills in nonexisting information or wrongly perceives geometrical properties of objects