Can I display the area of a raster image?
May 12, 2011 Leave a comment
The areas of fields, oak groves or bodies of water that you see on a raster image don’t mean a thing to a software function that computes areas. If you were to find the area of a rectangle, you will need to know the length and width of the rectangle in order to apply the l x w formula. Similarly, the software needs to know the relationship between the lines and curves that encompass the area in order to compute the area.
The Line and Area Features created by iCMTGIS and iGPSGIS contain such vector information. So do the polylines and polygons in a Shapefile. Therefore, the View Area function will work on such shapes. With a built-in Map, a topo map or an aerial photo, you will need to help the software by digitizing around the area of interest to make an Area Feature. Then iCMTGIS and iGPSGIS will be able to display the area for you.