|
|
Bardia Region Overview - Image processing - Part 3  This excercise is divided into eight parts and requires the use of LEOWorks. In a greyscale image, it is difficult to identify various Earth surface features with the human eye. It is therefore useful to combine 3 greyscale images into one RGB colour image to increase its interpretability. In this exercise, three-band composite images will be created by using three Landsat spectral bands to control the amount of red, green and blue in a colour image. The nature of the features being investigated will determine which 3 bands out of the 7 are chosen to be displayed as red, green, and blue. The true-colour combination requires the Red (band 3 - 0, 63 - 0, 69 µm), the Green (band 2 - 0, 52 - 0, 60 µm) and the Blue (band 1 - 0, 45 - 0, 52 µm) Landsat channels. Open the LEOWorks programme. If you have not downloaded the images of Bardia yet, go to Download at the top of the Worksheet and follow the instructions. If they are not on your screen yet, open:
Use Image>Combine from… to generate a colour image assigning band 3 to red, band 2 to blue, and band 1 to green.
1. Describe the image in general.
2. Why does enhancing improve the quality of an image? 3. Which features of Bardia can you identify in the Landsat true-colour image? Point to the Karnali bridge (NW corner of the image and the Park), the forests, clearances, agriculture, etc. Which features in the image are clearer? 4. Describe the image by dividing land cover into five groups: forests, grass lands, agricultural lands, rivers and river beds. 5. Why does this combination lead to an image closely resembling a colour photograph? What happens if you change the order? (e.g. Red = band 1, Blue = band 2 and Green = band 3)
Last update: 16 April 2013
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Previous