ImageExtensionsBeginConvertPixelFormat(Image, PixelFormat, Color, Color, Byte, AsyncConfig) Method

public static IAsyncResult BeginConvertPixelFormat(
	this Image image,
	PixelFormat newPixelFormat,
	Color[]? palette,
	Color backColor = default,
	byte alphaThreshold = 128,
	AsyncConfig? asyncConfig = null
)

<ExtensionAttribute>
Public Shared Function BeginConvertPixelFormat ( 
	image As Image,
	newPixelFormat As PixelFormat,
	palette As Color(),
	Optional backColor As Color = Nothing,
	Optional alphaThreshold As Byte = 128,
	Optional asyncConfig As AsyncConfig = Nothing
) As IAsyncResult

public:
[ExtensionAttribute]
static IAsyncResult^ BeginConvertPixelFormat(
	Image^ image, 
	PixelFormat newPixelFormat, 
	array<Color>^ palette, 
	Color backColor = Color(), 
	unsigned char alphaThreshold = 128, 
	AsyncConfig^ asyncConfig = nullptr
)

[<ExtensionAttribute>]
static member BeginConvertPixelFormat : 
        image : Image * 
        newPixelFormat : PixelFormat * 
        palette : Color[] * 
        ?backColor : Color * 
        ?alphaThreshold : byte * 
        ?asyncConfig : AsyncConfig 
(* Defaults:
        let _backColor = defaultArg backColor new Color()
        let _alphaThreshold = defaultArg alphaThreshold 128
        let _asyncConfig = defaultArg asyncConfig null
*)
-> IAsyncResult 

Parameters

image  Image

The original image to convert.

newPixelFormat  PixelFormat

The desired new pixel format.

palette  Color

The desired target palette if newPixelFormat is an indexed format. If , then the source palette is taken from the source image if it also has a palette of no more entries than the target indexed format can have; otherwise, a default palette will be used based on newPixelFormat.

backColor  Color  (Optional)

If newPixelFormat does not support alpha or supports only single-bit alpha, then specifies the color of the background. Source pixels with alpha, which will be opaque in the result will be blended with this color. The Color.A property of the background color is ignored. This parameter is optional.
Default value: Empty, which has the same RGB values as Black.

alphaThreshold  Byte  (Optional)

If newPixelFormat can represent only single-bit alpha or newPixelFormat is an indexed format and the target palette contains a transparent color, then specifies a threshold value for the Color.A property, under which the color is considered transparent. If 0, then the result will not have transparent pixels. This parameter is optional.
Default value: 128.

asyncConfig  AsyncConfig  (Optional)

The configuration of the asynchronous operation such as parallelization, cancellation, reporting progress, etc. When Progress is set in this parameter, then this library always passes a DrawingOperation instance to the generic methods of the IAsyncProgress interface. This parameter is optional.
Default value: .

Return Value

Usage Note

In .NET Framework 4.0 and above you can use also the ConvertPixelFormatAsync(Image, PixelFormat, Color, Color, Byte, TaskConfig) method.

To get the result or the exception that occurred during the operation you have to call the EndConvertPixelFormat method.

This method is not a blocking call even if the MaxDegreeOfParallelism property of the asyncConfig parameter is 1.

Reference