readme

Author: joshday

README.md

@@ -25,4 +25,25 @@ str = geojson(features[])  # String representation of the GeoJSON
 write("features.geojson", str)  # Save the GeoJSON to a file
 ```
 
+
+## Graphical User Interface
+
 ![](https://github.com/user-attachments/assets/dc7c8641-873b-4b9f-ade9-cff07a01b3ee)
+
+The above GUI is launched via the `draw_features` function.  The left panel contains the UI, and the right panel contains the map/raster.
+
+Going top down, the UI contains the following components:
+
+### Display Settings
+
+- **Aggregate Function and Aggregate Scale.**  To avoid visualizing every pixel of a large raster, InteractiveGeospatial will aggregate the raster data into a smaller number of bins.  These two inputs are passed to the [`Rasters.aggregate`](https://rafaqz.github.io/Rasters.jl/dev/api#Rasters.aggregate) function.
+- **Remap Function**.  This function is applied to the raster data before visualization.  For example, you can apply a logarithmic transformation to the data.
+- **Colormap**.  The color map used to visualize the raster data.
+
+### Draw Polygon
+
+- **Color**.  The color of the polygon and text displayed over the image.
+- **Clear Current Drawing**.  Clear the current drawing.
+- **Label (Unique Identifier)**.  Polygons must be labeled with a unique name before they can be saved.
+- **Save to Return Value**.  Save the polygon to the returned `Observable` from the `draw_features` function.
+- **View Drawing**.  Display a previously-saved polygon over the image.