ColorCorrectionFilter Class

Modifies an image using a color lookup table (a.k.a. "color grading").

Inheritance Hierarchy

SystemObject
DigitalRune.Graphics.PostProcessingPostProcessor
DigitalRune.Graphics.PostProcessingColorCorrectionFilter

Namespace: DigitalRune.Graphics.PostProcessing
Assembly: DigitalRune.Graphics (in DigitalRune.Graphics.dll) Version: 1.2.0.0 (1.2.1.14562)

Syntax

C++

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public class ColorCorrectionFilter : PostProcessor

Public Class ColorCorrectionFilter
	Inherits PostProcessor

public ref class ColorCorrectionFilter : public PostProcessor

type ColorCorrectionFilter =  
    class
        inherit PostProcessor
    end

The ColorCorrectionFilter type exposes the following members.

Constructors

	Name	Description
	ColorCorrectionFilter	Initializes a new instance of the ColorCorrectionFilter class.

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Methods

	Name	Description
	ConvertLookupTexture	Converts a 2D lookup texture to a 3D lookup texture.
	CreateLookupTexture2D(GraphicsDevice)	Creates the default 2D lookup texture (no color transformations) with 16 entries per color channel.
	CreateLookupTexture2D(GraphicsDevice, Int32)	Creates the default 2D lookup texture (no color transformations) with the specified lookup table size.
	Dispose	Releases all resources used by an instance of the PostProcessor class. (Inherited from PostProcessor.)
	Dispose(Boolean)	Releases the unmanaged resources used by an instance of the PostProcessor class and optionally releases the managed resources. (Overrides PostProcessorDispose(Boolean).)
	Equals	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	OnDisable	Called when this post-processor is disabled. (Inherited from PostProcessor.)
	OnEnable	Called when this post-processor is enabled. (Inherited from PostProcessor.)
	OnProcess	Called when the post-processor should perform the post-processing. (Overrides PostProcessorOnProcess(RenderContext).)
	Process	Performs the post-processing using the SourceTexture and the RenderTarget specified in the render context. (Inherited from PostProcessor.)
	SetLookupTexture	Obsolete. Sets the 3D lookup texture (LookupTextureA). (Overwrites the existing 3D lookup texture.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Properties

	Name	Description
	DefaultTargetFormat	Gets or sets the default target format. (This property is used by the PostProcessorChain). (Inherited from PostProcessor.)
	Enabled	Gets or sets a value indicating whether this post-processor is enabled. (Inherited from PostProcessor.)
	GraphicsService	Gets the graphics service. (Inherited from PostProcessor.)
	InterpolationParameter	Gets or sets the interpolation parameter for interpolating between the result of LookupTextureA and LookupTextureB.
	IsDisposed	Gets a value indicating whether this post-processor has been disposed of. (Inherited from PostProcessor.)
	LookupTexture	Obsolete. Gets or sets the primary color lookup texture (a 3D texture). Same as LookupTextureA.
	LookupTextureA	Gets or sets the primary color lookup texture (a 3D texture).
	LookupTextureB	Gets or sets a secondary, optional color lookup texture (a 3D texture).
	Name	Gets or sets the name of the post-processor. (Inherited from PostProcessor.)
	Strength	Gets or sets the strength of the effect.

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Remarks

This processor uses a 3D volume texture as a color lookup table to transform the colors of an image. LookupTextureA can be set directly. But it is usually easier to load it from a 2D texture. The method CreateLookupTexture2D(GraphicsDevice) creates a default 2D lookup texture (without any color transformations). Use ConvertLookupTexture(Texture2D) to convert a 2D lookup texture to a 3D lookup texture.

Workflow:
To define a color lookup texture, the artist can use following steps:

Make a screenshot of the game and load it in Photoshop.
Load the default lookup texture in Photoshop.
Copy the lookup texture in Photoshop and paste it into the document with the screenshot.
Apply color manipulations to the screenshot and the lookup texture. (Usually using adjustment layers.)
Select the lookup table inside the screenshot. (Select the layer with the lookup table and use the menu Select | Load Selection.)
Select the menu Edit | Copy Merged to select the lookup table including the adjustments.
Paste the lookup texture into a new image and save it.

(Of course the color lookup texture can also be created in any other image editing tool.)

Interpolation between lookup textures:
Optionally, you can set a second lookup texture in LookupTextureB and use InterpolationParameter to interpolate between both. This can be used to gradually change the color correction when transitioning to a new zone in the game level. If only LookupTextureA or LookupTextureB is set, then one lookup texture is applied with the specified Strength and InterpolationParameter is ignored.

Reference

DigitalRune.Graphics.PostProcessing Namespace