Flat featureless image areas have to be used to build accurate device noise profiles.

In the example below, the flat featureless area is marked with white frame and several areas that are not featureless are marked with black frames.

Auto Profile function in Neat Image plug-in /Mac can automatically find flat featureless areas if such areas exist in the input image. You can also select such an area manually. If there are no such areas then you have to use either another image from the same series or the Calibration Target to build new noise profile for the input image.

To build a noise profile:

• click the Auto Profile button to automatically find and analyze a flat featureless area in the input image
  or
• select such an area manually and then click the Auto Profile button to automatically analyze the selected area