BitmapSourceExtensionsConvertPixelFormatAsync(BitmapSource, PixelFormat, Color, Color, Byte, TaskConfig) Method
Namespace: KGySoft.Drawing.WpfAssembly: KGySoft.Drawing.Wpf (in KGySoft.Drawing.Wpf.dll) Version: 8.1.0
public static Task<WriteableBitmap?> ConvertPixelFormatAsync(
this BitmapSource bitmap,
PixelFormat newPixelFormat,
Color[]? palette,
Color backColor = default,
byte alphaThreshold = 128,
TaskConfig? asyncConfig = null
)
<ExtensionAttribute>
Public Shared Function ConvertPixelFormatAsync (
bitmap As BitmapSource,
newPixelFormat As PixelFormat,
palette As Color(),
Optional backColor As Color = Nothing,
Optional alphaThreshold As Byte = 128,
Optional asyncConfig As TaskConfig = Nothing
) As Task(Of WriteableBitmap)
public:
[ExtensionAttribute]
static Task<WriteableBitmap^>^ ConvertPixelFormatAsync(
BitmapSource^ bitmap,
PixelFormat newPixelFormat,
array<Color>^ palette,
Color backColor = Color(),
unsigned char alphaThreshold = 128,
TaskConfig^ asyncConfig = nullptr
)
[<ExtensionAttribute>]
static member ConvertPixelFormatAsync :
bitmap : BitmapSource *
newPixelFormat : PixelFormat *
palette : Color[] *
?backColor : Color *
?alphaThreshold : byte *
?asyncConfig : TaskConfig
(* Defaults:
let _backColor = defaultArg backColor new Color()
let _alphaThreshold = defaultArg alphaThreshold 128
let _asyncConfig = defaultArg asyncConfig null
*)
-> Task<WriteableBitmap>
- bitmap BitmapSource
- The original bitmap 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: 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: .
TaskWriteableBitmapA 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
.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).
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.
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.
See the
Remarks section of the
ConvertPixelFormat(BitmapSource, PixelFormat, Color, Color, Byte) method for more details, or the other overloads for image examples.