1. Digital image processing
Why?

2. OK. Starting today, we start moving into:
Digital image processing – which is the science of extracting information from digital images of the earth using math (as opposed to airphoto interpretation).

3. Why process digitally?
Analyst can only distinguish 8-16 different shades of one color – computers can handle thousands.
Results are repeatable (theoretically, no human error)
Computers can handle huge datasets
Easier to store, upgrade, etc (digital data)
Continuous coverage of the entire globe (16 days for landsat)
Data is readily available

4. Manual interp (airphoto interp)
Tone
Size
Shape
Texture
Pattern
Height
Shadow
Site
association

5. Digital interpretation
Tone. Plus, perhaps, texture
But.. Can add other info such as elevation, slope, aspect, yada, yada

6. What can we do with image processing?
Class ID
Physical location
Physical data (ie. elevation, etc)

7. Directly measure: Color X,y Z (if you have stereo imagery)
Chlorophyll absorption
Vegetation biomass
Vegetation moisture
Soil moisture
Temperature
Texture/surface roughness
OH (clay) absorption

8. And hybrid variables Landcover/landuse Turbidity Vegetation stress
Geology/soils

9. Overview of image processing considerations
Problem statement
Image processing system
Data acquisition
Initial display and stats
Preprocessing
Analysis (turning the raw imagery into something useful)
To GIS, ho!
Solve problems.
Assess results.
Rinse and repeat.