de.lmu.ifi.dbs.elki.data.images
Class BlendComposite.BlendingContext

java.lang.Object
  de.lmu.ifi.dbs.elki.data.images.BlendComposite.BlendingContext

All Implemented Interfaces:

CompositeContext

Direct Known Subclasses:

BlendComposite.AverageBlendingContext, BlendComposite.DarkenBlendingContext, BlendComposite.LightenBlendingContext, BlendComposite.MultiplyBlendingContext, BlendComposite.OverlayBlendingContext, BlendComposite.ScreenBlendingContext

Enclosing class:

BlendComposite

protected class BlendComposite.BlendingContext
extends Object
implements CompositeContext

Abstract blending context that takes care of color space conversion and pixel iteration. The base class does simple replacing.

Field Summary

protected double	alpha Opacity factor
private ColorModel	dstColorModel Destination color model
protected double	ialpha Additive inverse of alpha value.
private ColorModel	srcColorModel Source color model

Constructor Summary

protected

BlendComposite.BlendingContext(ColorModel srcColorModel, ColorModel dstColorModel, double alpha) Constructor.

Method Summary

protected int	blend(int sA, int sR, int sG, int sB, int dA, int dR, int dG, int dB) The actual blending function for two colors.
void	compose(Raster src, Raster dstIn, WritableRaster dstOut) Compose a raster image (source) and a background (destination) to a result raster.
void	dispose()
protected int	mixAlpha(int nA, int nR, int nG, int nB, int dA, int dR, int dG, int dB) Mix the new values with the original values taking the alpha value into account.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

srcColorModel

private ColorModel srcColorModel

Source color model

dstColorModel

private ColorModel dstColorModel

Destination color model

alpha

protected double alpha

Opacity factor

ialpha

protected double ialpha

Additive inverse of alpha value.

Constructor Detail

BlendComposite.BlendingContext

protected BlendComposite.BlendingContext(ColorModel srcColorModel,
                                         ColorModel dstColorModel,
                                         double alpha)

Constructor.

Parameters:

srcColorModel - source color model

dstColorModel - destination color model

alpha - Alpha (opacity) factor

Method Detail

dispose

public void dispose()

Specified by:

dispose in interface CompositeContext

compose

public void compose(Raster src,
                    Raster dstIn,
                    WritableRaster dstOut)

Compose a raster image (source) and a background (destination) to a result raster.

Specified by:

compose in interface CompositeContext

blend

protected int blend(int sA,
                    int sR,
                    int sG,
                    int sB,
                    int dA,
                    int dR,
                    int dG,
                    int dB)

The actual blending function for two colors.

Parameters:

sA - source alpha component (0-255)

sR - source red component (0-255)

sG - source green component (0-255)

sB - source blue component (0-255)

dA - destination alpha component (0-255)

dR - destination red component (0-255)

dG - destination green component (0-255)

dB - destination blues component (0-255)

Returns:

Combined color in single-integer ARGB format (see BlendComposite.combineComponents(int, int, int, int) and mixAlpha(int, int, int, int, int, int, int, int) helper functions)

mixAlpha

protected int mixAlpha(int nA,
                       int nR,
                       int nG,
                       int nB,
                       int dA,
                       int dR,
                       int dG,
                       int dB)

Mix the new values with the original values taking the alpha value into account.

Parameters:

nA - new alpha component (0-255)

nR - new red component (0-255)

nG - new green component (0-255)

nB - new blue component (0-255)

dA - old alpha component (0-255)

dR - old red component (0-255)

dG - old green component (0-255)

dB - old blue component (0-255)

Returns:

Combined color in single-integer ARGB format.