ContrastEffect Class |
Namespace: Microsoft.Graphics.Canvas.Effects
public sealed class ContrastEffect : ICanvasEffect, IGraphicsEffect, IGraphicsEffectSource, ICanvasImage, IDisposable
The ContrastEffect type exposes the following members.
Name | Description | |
---|---|---|
ContrastEffect | Initializes a new instance of the ContrastEffect class. |
Name | Description | |
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BufferPrecision | Specifies what precision to use for intermediate buffers when drawing this effect. | |
CacheOutput | Enables caching the output from drawing this effect. | |
ClampSource | Indicates whether to clamp input values to 0-1 range before contrast adjustment. Default value false. | |
Contrast | Amount by which to adjust the contrast of the image. Default value 0, range -1 to 1. | |
Name | Attaches a user-defined name string to the effect. | |
Source | Gets or sets the input source for Contrast effect. |
Name | Description | |
---|---|---|
Dispose | Releases all resources used by the effect. | |
GetBounds(ICanvasResourceCreator) | Retrieves the bounds of this ContrastEffect. | |
GetBounds(ICanvasResourceCreator, Matrix3x2) | Retrieves the bounds of this ContrastEffect. | |
GetInvalidRectangles | Queries what regions of the effect output have changed since it was last drawn. | |
GetRequiredSourceRectangle | Queries what part of an effect source image is needed to draw an output region. | |
GetRequiredSourceRectangles | Queries what parts of the effect source images are needed to draw an output region. | |
InvalidateSourceRectangle | Notifies the effect that one of its source images has changed. |
The contrast function modifies each color channel value using two piecewise quadratic polynomials that meet with slope continuity at the point (0.5, 0.5).
Effect inputs and outputs are assumed to be in premultiplied alpha format, but this effect operates internally on straight alpha data, so its input values will be unpremultiplied, then the contrast adjustment applied, and finally the result converted back to premultiplied format.
This Windows Runtime type corresponds to the D2D Contrast effect.