Raster image data is in GeoTIFF format.
A raster file contains a matrix of pixels that are organized into rows and columns. Each pixel can be regarded as a cell and contains a value that represents a specific type of data, such as temperature or height. Rasters can be satellite images, digital images and even scanned maps. A shapefile, or “.shp” file, is a vector data format used by many geographic information systems, or GIS, software. Converting a raster to a shapefile is possible if you use a third-party tool.
1. Open your Web browser and enter this address into the address bar: sourceforge.net/projects/saga-gis/files/. Click on the “SAGA – 2.0” link. You see a list containing all versions. Click on the “SAGA 2.0.8” link. Click on the “saga_2.0.8_x64_setup.exe” or “saga_2.0.8_win32_setup.exe” file, depending on your operating system’s architecture, to start downloading the installer.
2. Save the setup file somewhere on your hard disk drive. Double-click the executable file to start installing the SAGA software. Follow the on-screen instructions to install the tool.
3. Double-click the SAGA icon on your desktop or click the SAGA icon in the Start menu to start the tool.
4. Click the “Modules” menu. Click “File,” “Grid” and double-click on “Import.” Click “Image” and use the file browser to highlight the raster file. Click “False” in the Split Channels drop-down box. Click “OK” to open the raster file.
5. Click the “Modules” menu, “Grid,” “Shapes,” and double-click on “Vectorising Grid Classes.” Select the raster you imported in the Input Grid and select “Polygons” in the Output As drop-down menu. Click “OK” and wait for the program to finish vectorising the raster. You hear a sound when the operation is complete.
6. Click the “Shapes” tab you see in the bottom left corner. Right-click on the shape layer created by vectorising the raster and click “Save” from the resulting menu. Click “Shapefile (.shp)” as the file type and enter a name for your new shapefile. Select a location where to save the shapefile and click on the “Save” button to save it.