BitmapSourceExtensionsConvertPixelFormatAsync(BitmapSource, PixelFormat, Color, Byte, TaskConfig) Method

Converts the specified bitmap to a WriteableBitmap of the desired PixelFormat asynchronously.

Definition

Namespace: KGySoft.Drawing.Wpf
Assembly: KGySoft.Drawing.Wpf (in KGySoft.Drawing.Wpf.dll) Version: 8.1.0
C#
public static Task<WriteableBitmap?> ConvertPixelFormatAsync(
	this BitmapSource bitmap,
	PixelFormat newPixelFormat,
	Color backColor = default,
	byte alphaThreshold = 128,
	TaskConfig? asyncConfig = null
)

Parameters

bitmap  BitmapSource
The original bitmap to convert.
newPixelFormat  PixelFormat
The desired new pixel format.
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: The bitwise zero instance of Color, 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  TaskConfig  (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

TaskWriteableBitmap
A task that represents the asynchronous operation. Its result is the new WriteableBitmap instance with the desired pixel format, or , if the operation was canceled and the ThrowIfCanceledproperty of the asyncConfig parameter was .

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type BitmapSource. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

Alternatively, you can also use the BeginConvertPixelFormat(BitmapSource, PixelFormat, Color, Byte, AsyncConfig) method, which is available on every platform.

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

  Caution

This method can be called from any thread but if it is called from a different one from the thread of the source bitmap's dispatcher, then the result WriteableBitmap will be created by using a synchronized callback. To avoid possible deadlocks, the thread of the source bitmap must not be blocked and the dispatcher must run. The result will be usable in the same thread as the source bitmap. To avoid blocking waiting for the result use the keyword in C# (when using .NET Framework 4.5 or newer), or use the Task.ContinueWith method to access the Result of the completed task from there.

Exceptions

ArgumentNullExceptionbitmap is .
ArgumentOutOfRangeExceptionnewPixelFormat does not specify a valid format.

See Also