Distortion
The Distortion Raster Preview shows the distortion caused by the web growth. When Distortion is selected, Raster Preview applies the web-growth compensation, otherwise Raster Preview shows the uncompensated raster.
NOTE: This option requires a special license.
To view the DistortionĀ 
Select the Preview window which contains the image you want to view the distortion.
*Choose Window > Palettes > Show Tools to open the Tools palette and click Distortion (Web Growth) tool button.
OR
*Choose View > Distortion (Web Growth), or press ALT+G.
You can toggle between the distorted and not-distorted views. To view the distortion better, it is recommended to zoom in higher resolutions.
doc. version 13.1.1