Auto Defeat Controls are required to manually disable any automated or default display features, such as black level enhancement, flesh tone correction, digital noise reduction, etc.
Similar to edge enhancement, features that claim to "enhance" or "correct" some aspect of video display performance typically involve a significant degree of manipulation or distortion of the source video signal. By definition, such extracurricular video processing violates the most fundamental tenet of proper display design – faithfully delivering the complete and unaltered content of the source video signal, in full compliance with agreed industry standards.
While a casual viewer or uneducated consumer may find some initial appeal in these enhancement and correction features, for the discriminating viewer, these features are unwelcome. As a result, there should be some facility for selectively removing or defeating these features, so that the display is fully capable of displaying the content of the video signal, with nothing added or removed.
Note that the range and presence of these automated features vary widely among manufacturers, technologies and form factors.
This is one of the murkiest areas of display design, due to the fact that there is a complete lack of consistency in the naming and application of enhancement/correction features among display manufacturers. In some cases, these features are aggressively promoted as selling points, and therefore are easily detected; but in other cases, these distortions exist far below the surface, excluded from any feature list or specification sheet and ultimately out of the reach of the average user.
In those cases where enhancement circuitry cannot be readily defeated via user or service controls, it may still be possible to eliminate it by completely bypassing the the display’s internal video processing chain through the use of an external video scaler/processor configured to deliver a signal setup for the display’s native resolution.