Remote Sensing and GIS Application Lecturer Ruba Yousif
Remote Sensing and GIS Application Lecturer Ruba Yousif Hussain Third Year 1
Remote Sensing and GIS Application Third Year Lecturer Ruba Yousif Hussain Laboratory Creating a Composite Image Purpose By creating a composite image , you can display the images in color. Displaying bands in the RGB format allows you to see different features within a scene and become more familiar with the scene to identify urban areas , forests , agriculture , and water bodies. Familiarity with your image scene is important in order to do different types of analyses, such as classification and different indices. The electromagnetic spectrum differs for each band. Each one of these bands is useful for distinguishing different features. Application Arc. GIS Tutorial Open Arc. Map Open new map document Add all bands to map document Remember, each image will be listed separately in Table of Contents and displayed in the Arc. Map document window on top of each other , so you will only see the image listed on top. Set Workspace Open Image Analysis window. 2
Remote Sensing and GIS Application Third Year Lecturer Ruba Yousif Hussain In the top of the Image Analysis window , highlight all bands. Notice that several additional buttons are now enabled. 3
Remote Sensing and GIS Application Third Year Lecturer Ruba Yousif Hussain Left click on this button. This button creates a temporary composite image containing all bands. Why do we want to create a composite image ? Compositing an image will allow us to display the image in color , most specifically in RGB style ( Red , Green , Blue ). The human eye can only see that portion of the electromagnetic spectrum within the visual spectrum. By Compositing the image , we can display different bands using the RGB color scheme , even those not visible to the naked eye. The composite file that you will created is a temporary file. If you look in your workspace folder, you will not see this file listed. It cannot be added to any other map document and if you close this map document without saving the map document , it will disappear. You can use this temporary file if you immediately plan to proceed to the Creating Different Band Combinations tutorial. We recommended that you make this file permanent by saving it. 4
Remote Sensing and GIS Application Third Year Lecturer Ruba Yousif Hussain Saving New Composite Image Under the processing section , left click on save button. Click save. 5
Remote Sensing and GIS Application Third Year Lecturer Ruba Yousif Hussain Click No Click Yes. The file is now a permanent file. 6
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