Add information about georeferenced images to user guide

pozi · Sep 6, 2024 · 88d597c · 88d597c
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diff --git a/user-guide/img/print-map.png b/user-guide/img/print-map.png
diff --git a/user-guide/img/qgis-crs-settings.png b/user-guide/img/qgis-crs-settings.png
diff --git a/user-guide/img/qgis-layer-without-projection.png b/user-guide/img/qgis-layer-without-projection.png
diff --git a/user-guide/img/qgis-open-raster-layer.png b/user-guide/img/qgis-open-raster-layer.png
diff --git a/user-guide/img/qgis-project-crs.png b/user-guide/img/qgis-project-crs.png
diff --git a/user-guide/img/qgis-select-crs.png b/user-guide/img/qgis-select-crs.png
diff --git a/user-guide/img/save-map-as-image.png b/user-guide/img/save-map-as-image.png
diff --git a/user-guide/img/save-map-world-file.png b/user-guide/img/save-map-world-file.png
diff --git a/user-guide/print.md b/user-guide/print.md
@@ -7,7 +7,7 @@ icon: file-symlink-file
 
 The Pozi map view and associated information can be saved to a PDF for printing or sharing.
 
-`Menu` > `Tools` > `Print/Save` > `Print`
+![](./img/print-map.png){style="width:200px"}
 
 ## Settings
 
@@ -68,10 +68,46 @@ Pick from these scales:
 
 ##### Add Statistics
 
-Print an addition page that contains statistics for any active vector layer. Pozi will generate statistics based on the any number fields for any features within the map bounds.
+Print an additional page that contains statistics for any active vector layer. Pozi will generate statistics based on the any number fields for any features within the map bounds.
 
 ## Save Map
 
-The Pozi map view can be exported to an image that you can save to your device.
+The current Pozi map view can be exported to an image file on your device.  Go to the `Tools` panel in Pozi and select `Print\Save`.
 
-`Menu` > `Tools` > `Print/Save` > `Print`
+![](./img/save-map-as-image.png)
+
+When selected, the option to `Save map as image` will save the map as a **PNG**, and will expose the option to save a corresponding world file
+
+![](./img/save-map-world-file.png)
+
+If this button is pushed a **.PNGW** file will also be downloaded that contains georeference information about the image. 
+
+The image and the world file will have the same name but different extensions. So if the image file is **"Bendigo Community Compass 20240906073714.png"**, the world file created will be called **"Bendigo Community Compass 20240906073714.pngw"**.
+
+### Adding a Georeferenced Image to QGIS
+
+Start QGIS.
+
+Select `Layer` -> `Add Layer` -> `Add Raster Layer..` to open the following dialog:
+
+![](./img/qgis-open-raster-layer.png)
+
+Navigate to the downloaded PNG file, and then click the `Add` button.  Then click the `Close` button
+
+You might see a warning message that the CRS for the image is undefined, if you have QGIS set to `Prompt for CRS` (see below).
+
+![](./img/qgis-crs-settings.png)
+
+In any case the world file (.PNGW file) will be applied to the image as long as it is in the same directory as the PNG file.
+
+To correctly project the image the new layers projection should be set to **EPSG:3857**.  This can either be done when prompted, or by clicking on the question mark next to the layer in the `Layer Panel`.  Depending on any other layers that are currently open in QGIS, it may correctly guess the projection without requiring the CRS to be set.
+
+![](./img/qgis-layer-without-projection.png)
+
+In the dialog box that presents, filtering to `3857` will limit the list to the relevant projection.  Then select `WGS 84 / Pseudo-Mercator` in the highlighted box and push the `OK` button.
+
+![](./img/qgis-select-crs.png)
+
+Depending on the project based CRS that is currently defined, the image may disappear from view and/or appear distorted once the layer CRS has been set.  In order to remove distortion set the project based CRS to `WGS 84 / Pseudo-Mercator` by clicking on the `EPSG` setting in the bottom-right corner of the screen.  If the image is still out of view the `Zoom to Layer` or `Previous Zoom` functionality of QGIS can be used to zoom to the correct location.
+
+![](./img/qgis-project-crs.png)