Revealing rasters using the Flicker tool

You can reveal hidden layers using the Flicker tool. This lets you display the layers underneath a particular layer by quickly turning it on and off. This is useful for temporal change detection (especially of satellite images or aerial photographs taken at different times of the same location), data quality comparison, and other analysis where you want to see the difference between layers.

You can access the Flicker tool from within the Image Analysis window, where you interact with raster layers, and also from the Effects toolbar, where you can interact with any layer in the table of contents.

To use the Flicker tool from the Effects toolbar, choose the layer you want to turn on and off from the Layer drop-down menu on the Effects toolbar. Click the Flicker button to start flickering and click the button again to stop flickering. You can adjust the flicker interval in the Flicker Rate box.

To use the Flicker tool from within the Image Analysis window, see the steps below.

Steps:

1. To view the Image Analysis window, click Windows on the Main menu and click Image Analysis.
2. Click the raster layer in the Image Analysis window that you want to look underneath.

   This raster layer must be visible to view it in the Image Analysis window.

3. Set the flicker interval you want (in milliseconds) in the Flicker Rate box.
4. Click the Flicker button to start.
5. Click the button again to stop flickering.

   You can also stop flickering by zooming or panning the display (if you are using a 2D map).