Image overlays can be used to quickly render frequently changing images in a map view or scene view. For example, you can render real-time sensor data, such as weather, where each static image displayed represents a single frame from the radar satellite image. A user perceives the display of the static images in succession as an animation if the images are displayed at small enough time intervals.
Image overlays and graphics overlays both render above all layers in the map or scene. Image overlays render below any graphics overlays you've added to the view. This order ensures that graphics you want to display won't be obscured by your image overlays. For example, you might want to show graphics representing aircraft on top of image overlays showing the sensor data they are collecting.
Since they are designed for quick display, image overlays do not support the rich processing and rendering capabilities of a raster layer, which still provides the best option for workflows that require static image rendering, analysis, and persistence. See Add raster data for more information about working with raster layers.
Add an image overlay
A map or scene view manages a collection of image overlays. Each ImageOverlay contains a single ImageFrame that defines an image to display. Georeferenced images (those with a world file) are added at the correct geographic location. Otherwise, you must define a geographic extent for the image frame. If a spatial reference is not defined for the extent, it is assumed to be the same as the map or scene. If the spatial reference of the extent is different from that of the map or scene, the image will fail to render.
Animate an image overlay
You can animate the display of image overlays by changing the frame they contain at a specified interval. You might use a timer, for example, to read the next image in a sequence, use it to create a new ImageFrame, and replace the current frame in the ImageOverlay.