Halftone Palette and Color Adjustment
Halftone palettes are intended to be used whenever the stretching mode of a device context is set to HALFTONE. An application creates a halftone palette by using the CreateHalftonePalette function. The application must select and realize this palette into the device context before calling the StretchBlt or StretchDIBits function.
The system automatically adjusts the input color of source bitmaps whenever applications call the StretchBlt and StretchDIBits functions and the stretching mode of a device context is set to HALFTONE. These color adjustments affect certain attributes of the image, such as contrast and brightness. An application can set the color adjustment values by using the SetColorAdjustment function. The application can retrieve the color adjustment values for the specified device context by using the GetColorAdjustment function.