1. ERDAS 1: INTRODUCTION TO ERDAS IMAGINE
GEO 420

2. Goals: Display raster image using panchromatic, normal & false color.
Use zoom tool/buttons to properly display image and inquire cursor to identify pixel locations and digital numbers.
Display image automatically scaled with DN’s stretched from 0-255, or with natural spectral variation.
Use histogram to view spectral variability and frequency/proportion of DN’s within each class.
4. Perform a linear contrast stretch
5. Measure distances and areas within an image.
6. Create spatial and spectral profiles of an image.

3. 1. Displaying an Image
No stretch image
View/Edit Image Metadata

4. Lanier.img - Landsat Thematic Mapper (TM) image that has 7 wavebands of information with 512 rows and columns of raster information.
You have displayed a False Color Composite which sends Near Infrared (NIR) Light in TM Band 4 to the Red color gun, Red Light in TM Band 3 to the Green gun, and Green Light TM Band 2 to the Blue gun.
Display Options settings - No Stretch – so it looks dark.
Home > Metadata Icon and choose View/Edit Image Metadata - gives you all of the info Imagine has on this image (number of layers is 7 for TM, min and max DN values, the Measurement Units, and the Projection (if any), etc.

5. 2. Inquire Cursor Utility

6. Google Earth Capabilities

7. 3. Histograms Type of Image Enhancement: Contrast manipulation
– contrast stretching of histogram distn

8. 4. Stretching an image
Swipe

9. 5. Measurements

10. 6. Spectral Profiles Band 1 = blue (high due to scattering)
Band 2 = green
Band 3 = red
Band 4 = near infrared
Band 6 = thermal

11. 6. Spatial Profiles

12. Landsat 7 and TM & ETM+ Characteristics:
Band Spectral Range(µm) Resolution(m) to to
.63 to
.75 to
1.55 to to
10.40 to (thermal) 60

13. NDVI