Automatic Gamma Correction

The automatic gamma correction mode is introduced to simplify gamma correction. Automatic gamma correction automatically chooses a gamma value when loading a bitmap in certain cases and always when saving a bitmap. The gamma value is determined based on the file type being used.

NOTE:Bitmap plug-ins that have to load and save linear data (not gamma encoded) can choose to export a new BitmapIOMetadata interface and implement a BitmapIOMetadata::UseLinearStorage() function.