BitmapDataExtensionsAdjustContrast(IReadWriteBitmapData, Single, IDitherer, ColorChannels) Method

public static void AdjustContrast(
	this IReadWriteBitmapData bitmapData,
	float contrast,
	IDitherer? ditherer = null,
	ColorChannels channels = ColorChannels.Rgb
)

<ExtensionAttribute>
Public Shared Sub AdjustContrast ( 
	bitmapData As IReadWriteBitmapData,
	contrast As Single,
	Optional ditherer As IDitherer = Nothing,
	Optional channels As ColorChannels = ColorChannels.Rgb
)

public:
[ExtensionAttribute]
static void AdjustContrast(
	IReadWriteBitmapData^ bitmapData, 
	float contrast, 
	IDitherer^ ditherer = nullptr, 
	ColorChannels channels = ColorChannels::Rgb
)

[<ExtensionAttribute>]
static member AdjustContrast : 
        bitmapData : IReadWriteBitmapData * 
        contrast : float32 * 
        ?ditherer : IDitherer * 
        ?channels : ColorChannels 
(* Defaults:
        let _ditherer = defaultArg ditherer null
        let _channels = defaultArg channels ColorChannels.Rgb
*)
-> unit 

Parameters

bitmapData  IReadWriteBitmapData

The IReadWriteBitmapData to be transformed.

contrast  Single

A float value between -1 and 1, inclusive bounds. Positive values increase the contrast, while negative values decrease it.

ditherer  IDitherer  (Optional)

An optional IDitherer instance to dither the result of the transformation if the transformed colors are not compatible with the PixelFormat of the specified bitmapData. This parameter is optional.
Default value: .

channels  ColorChannels  (Optional)

The ColorChannels, on which the adjustment has to be performed. This parameter is optional.
Default value: Rgb.

Usage Note

If bitmapData has an indexed PixelFormat and ditherer is , then its palette entries are tried to be transformed instead of the actual pixels in the first place (if it is supported by bitmapData). To transform the colors of an indexed IBitmapData without changing the palette specify a non- ditherer. Transforming the palette is both faster and provides a better result.

If ditherer is , this method attempts to preserve the original color depth, including wide pixel formats.

The ditherer may have no effect for KnownPixelFormats with more than 16 bits-per-pixel and for grayscale formats.

Reference