Color mixing and image enhancement

Wei Luo, Northern Illinois University


The objectives of this lab are: (1) to be familiar with reflectance spectra of vegetation especially in infrared region and understand color mixing; (2) to experience different image enhancement technique (contract stretching, band indexing/ratioing, and spatial filtering).


Type and level of course

This is a lab for an introductory remote sensing course after we covered image enhancement and color mixing in lectures.

Some background of ADAR image: The Airborne Data Acquisition and Registration (ADAR) System is an airborne multispectral digital camera system. The ADAR wavebands are band 1: blue (450-540 nm), band 2: green (520-600 nm), band 3: red (610-690 nm), and band 4: near-infrared (780-1000 nm). Note 1 μm =1,000 nm. The spatial resolution is 1 m (3.28084 ft). The image used in this exercise is taken over a golf course.

Geoscience background assumed in this assignment

GIS/remote sensing skills/background assumed in this assignment
basic understanding of remote sensing, electomagnetic wave, spectra, wavelength, color mixing, image enhancment

Software required for this assignment/activity:
ENVI 4.5

Time required for students to complete the assignment:
2 hours


GIS/remote sensing techniques students learn in this assignment
How to use reflectance at different wavelength and different color mixing to visualize and interprete image data

Other content/concepts goals for this activity

Higher order thinking skills goals for this activity
Data analysis and visualization

Description of the activity/assignment

Determining whether students have met the goals

given two input images and spectra of specific object, student is able to predict what specic objects will look like on the output image
More information about assessment tools and techniques.

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