SKBitmapExtensionsConvertPixelFormat(SKBitmap, SKColorType, SKAlphaType, WorkingColorSpace, SKColor, Byte) Method

Converts the pixel format of this bitmap using the specified colorType, alphaType and targetColorSpace.

Definition

Namespace: KGySoft.Drawing.SkiaSharp
Assembly: KGySoft.Drawing.SkiaSharp (in KGySoft.Drawing.SkiaSharp.dll) Version: 8.1.0
C#
public static SKBitmap ConvertPixelFormat(
	this SKBitmap bitmap,
	SKColorType colorType,
	SKAlphaType alphaType = SKAlphaType.Unknown,
	WorkingColorSpace targetColorSpace = WorkingColorSpace.Default,
	SKColor backColor = default,
	byte alphaThreshold = 128
)

Parameters

bitmap  SKBitmap
The original bitmap to convert.
colorType  SKColorType
Determines the ColorType property of the result SKBitmap. Can be Unknown to use the original color type of the source bitmap.
alphaType  SKAlphaType  (Optional)
Determines the AlphaType property of the result SKBitmap. It might be ignored if the colorType cannot have the specified alpha type. Can be Unknown to use the original alpha type of the source bitmap. This parameter is optional.
Default value: Unknown.
targetColorSpace  WorkingColorSpace  (Optional)
Determines both the ColorSpace property of the result SKBitmap, and also the working color space if the result does not support transparency and source pixels needed to be blended with backColor. Can be Default to preserve the original color space. This parameter is optional.
Default value: Default.
backColor  SKColor  (Optional)
If the result does not support 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 Alpha property of the background color is ignored. This parameter is optional.
Default value: The bitwise zero instance of SKColor, which has the same RGB values as Black.
alphaThreshold  Byte  (Optional)
If the result supports alpha, then specifies a threshold value for the Alpha property, under which the color is considered completely transparent. If 0, then the converted colors attempt to preserve their original alpha value. This parameter is optional.
Default value: 128.

Return Value

SKBitmap
A new SKBitmap instance with the desired parameters.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type SKBitmap. 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

  Note

If the result SKBitmap can represent fewer colors than the source bitmap, then a default quantization will occur during the conversion. To use a specific quantizer (and optionally a ditherer) use the ConvertPixelFormat(SKBitmap, IQuantizer, IDitherer, SKColorType, SKAlphaType, WorkingColorSpace) overload. To use a quantizer with a specific palette you can use the PredefinedColorsQuantizer class.

Example

The method may produce the following results:

Original image
Quantized image

Color hues with alpha gradient
Color hues with alpha gradient

Color hues with unpremultiplied ARGB4444 sRGB pixel format
colorType = Argb4444, alphaType = Unpremul, targetColorSpace = Srgb, the other parameters have their default value.

Color hues with RGB565 sRGB pixel format and black background
colorType = Rgb565, targetColorSpace = Srgb, the other parameters have their default value.

Color hues with RGB565 linear pixel format and black background
colorType = Rgb565, targetColorSpace = Linear, the other parameters have their default value.

Exceptions

ArgumentNullExceptionbitmap is .
ArgumentOutOfRangeExceptioncolorType, alphaType or targetColorSpace does not specify a defined value.

See Also