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#QGIS DEFINE RASTER EXTENT UPGRADE#
#QGIS DEFINE RASTER EXTENT FULL#
#QGIS DEFINE RASTER EXTENT SOFTWARE#

WGS 84 (EPSG:4326) is the standard coordinate reference system (CRS) used for georeferencing maps that are part of the PCL maps collection and it is recommended that you also select this CRS unless you have a specific reason for choosing another option. In the Project Properties window, click on CRS in the left hand column and then select the CRS you would like your project (and your georeferenced layers) to use in the main window panel.

To do this, click Project at the top of your QGIS window (Windows) or top of your screen (MacOS) and select Properties from the menu that appears. Prior to starting the georeferencing process, it is a good idea to select your QGIS project coordinate system as this will make some of the upcoming steps in this process a little easier. This is fine because we will be selecting the data to be used in the georeferencing process in an upcoming step. Once you have successfully opened QGIS you will notice that your project appears empty - this is because you do not have any data currently loaded into it.If you already have QGIS open, you can also check your version number by accessing the Help menu at the top of the screen and selecting Check QGIS Version.

#QGIS DEFINE RASTER EXTENT SOFTWARE#

If you already have QGIS installed but are unsure which version you have on your computer, try opening QGIS and look closely at the splash screen that displays as the software loads - the version number should be prominently indicated.

#QGIS DEFINE RASTER EXTENT UPGRADE#

Please keep in mind that this guide was developed for QGIS 3.x so if you have QGIS 2.x installed on your computer you will want to upgrade your installation before proceeding to ensure that these instructions match your software version.

Open up QGIS to create a new QQIS project that you can work in for georeferencing scanned map images (see QGIS installation guide if you do not already have the software installed).

#QGIS DEFINE RASTER EXTENT FULL#

Using the Raster > Extraction > Clip Raster by Extent tool to crop off the collar of the georeferenced map image and save it as a compressed JPG fileįor the full guide instructions, continue reading below.

Using the Raster > Georeferencer tool to assign ground control points to the four corners of the map extent of a scanned paper map raster image then saving the image with an assigned coordinate system.

It will walk you through the following major steps: The instructions provided in this guide are highly detailed to ensure that users are able to easily navigate the georeferencing process so you will notice that this guide is longer than most. This guide describes the georeferencing process in QGIS due to the fact that QGIS is free, open source, compatible with a variety of computer operating systems, and has georeferencing tools that are easy to learn and use (refer to the QGIS installation guide if you do not already have the software installed on your computer). If your map does not coordinate information at the corners of the map extent, you should consult the Georeference By Map Features guide instead as the georeferencing process is significantly different for maps lacking this coordinate information. This guide provides instructions for georeferencing scanned images of paper maps that have legible geographic coordinate information provided for each of the 4 corners of the map (see example images below).