BitmapExtensionsInvert Method

Inverts the colors of the specified bitmap.

Definition

Namespace: KGySoft.Drawing
Assembly: KGySoft.Drawing (in KGySoft.Drawing.dll) Version: 10.0.0-rc.1

C#

public static void Invert(
	this Bitmap bitmap,
	IDitherer? ditherer = null
)

VB

<ExtensionAttribute>
Public Shared Sub Invert ( 
	bitmap As Bitmap,
	Optional ditherer As IDitherer = Nothing
)

C++

public:
[ExtensionAttribute]
static void Invert(
	Bitmap^ bitmap, 
	IDitherer^ ditherer = nullptr
)

F#

[<ExtensionAttribute>]
static member Invert : 
        bitmap : Bitmap * 
        ?ditherer : IDitherer 
(* Defaults:
        let _ditherer = defaultArg ditherer null
*)
-> unit

Parameters

bitmap Bitmap: The Bitmap to be inverted.
ditherer IDitherer (Optional): An optional IDitherer instance to dither the result of the transformation if the inverse of the bitmap has no exact representation with its PixelFormat. This parameter is optional.
Default value: .

Usage Note

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

This method adjusts the degree of parallelization automatically, blocks the caller, and does not support cancellation or reporting progress. Use the BitmapDataExtensions.BeginInvert or BitmapDataExtensions.InvertAsync (in .NET Framework 4.0 and above) methods for asynchronous call and to adjust parallelization, set up cancellation and for reporting progress.

If bitmap has an indexed PixelFormat and ditherer is , then its palette entries will be transformed instead of the actual pixels. To transform the colors of an indexed Bitmap without changing the palette specify a non- ditherer. Transforming the palette is both faster and provides a better result.

The ditherer is ignored for PixelFormats with more than 16 bits-per-pixel and for the Format16bppGrayScale format.

Note

This method uses the color space that naturally matches the pixel format of the bitmap. To use an arbitrary color space, obtain an IReadWriteBitmapData instance by the GetReadWriteBitmapData(Bitmap, WorkingColorSpace, Color, Byte) method, and call the BitmapDataExtensions.Invert extension method on it.

Examples

Example 1: Simple usage

C#

using Bitmap bmp = Icons.Shield.ExtractBitmap(new Size(256, 256));
bmp.SaveAsPng(@"c:\temp\before.png");
bmp.Invert();
bmp.SaveAsPng(@"c:\temp\after.png");

The example above produces the following results:

before.png
after.png

Example 2: Using linear color space

This method uses the color space that naturally matches the pixel format of the bitmap. In Example 1 the original bitmap had a 32 BPP pixel format, so the sRGB color space was used. To specify a color space explicitly, you can obtain an IReadWriteBitmapData instance and use the BitmapDataExtensions.Invert method instead:

C#

using Bitmap bmp = Icons.Shield.ExtractBitmap(new Size(256, 256));
bmp.SaveAsPng(@"c:\temp\before.png");
using (IReadWriteBitmapData bitmapData = bmp.GetReadWriteBitmapData(WorkingColorSpace.Linear))
    bitmapData.Invert();
bmp.SaveAsPng(@"c:\temp\after.png");