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Added in API level 1

ColorMatrix

public class ColorMatrix
extends Object

java.lang.Object
   ↳ android.graphics.ColorMatrix


4x5 matrix for transforming the color and alpha components of a Bitmap. The matrix can be passed as single array, and is treated as follows:

  [ a, b, c, d, e,
    f, g, h, i, j,
    k, l, m, n, o,
    p, q, r, s, t ]

When applied to a color [R, G, B, A], the resulting color is computed as:

   R’ = a*R + b*G + c*B + d*A + e;
   G’ = f*R + g*G + h*B + i*A + j;
   B’ = k*R + l*G + m*B + n*A + o;
   A’ = p*R + q*G + r*B + s*A + t;

That resulting color [R’, G’, B’, A’] then has each channel clamped to the 0 to 255 range.

The sample ColorMatrix below inverts incoming colors by scaling each channel by -1, and then shifting the result up by 255 to remain in the standard color space.

   [ -1, 0, 0, 0, 255,
     0, -1, 0, 0, 255,
     0, 0, -1, 0, 255,
     0, 0, 0, 1, 0 ]

Summary

Public constructors

ColorMatrix()

Create a new colormatrix initialized to identity (as if reset() had been called).

ColorMatrix(float[] src)

Create a new colormatrix initialized with the specified array of values.

ColorMatrix(ColorMatrix src)

Create a new colormatrix initialized with the specified colormatrix.

Public methods

final float[] getArray()

Return the array of floats representing this colormatrix.

void postConcat(ColorMatrix postmatrix)

Concat this colormatrix with the specified postmatrix.

void preConcat(ColorMatrix prematrix)

Concat this colormatrix with the specified prematrix.

void reset()

Set this colormatrix to identity:

 [ 1 0 0 0 0   - red vector
   0 1 0 0 0   - green vector
   0 0 1 0 0   - blue vector
   0 0 0 1 0 ] - alpha vector
 

void set(float[] src)

Assign the array of floats into this matrix, copying all of its values.

void set(ColorMatrix src)

Assign the src colormatrix into this matrix, copying all of its values.

void setConcat(ColorMatrix matA, ColorMatrix matB)

Set this colormatrix to the concatenation of the two specified colormatrices, such that the resulting colormatrix has the same effect as applying matB and then applying matA.

void setRGB2YUV()

Set the matrix to convert RGB to YUV

void setRotate(int axis, float degrees)

Set the rotation on a color axis by the specified values.

void setSaturation(float sat)

Set the matrix to affect the saturation of colors.

void setScale(float rScale, float gScale, float bScale, float aScale)

Set this colormatrix to scale by the specified values.

void setYUV2RGB()

Set the matrix to convert from YUV to RGB

Inherited methods

From class java.lang.Object

Public constructors

ColorMatrix

Added in API level 1
ColorMatrix ()

Create a new colormatrix initialized to identity (as if reset() had been called).

ColorMatrix

Added in API level 1
ColorMatrix (float[] src)

Create a new colormatrix initialized with the specified array of values.

Parameters
src float

ColorMatrix

Added in API level 1
ColorMatrix (ColorMatrix src)

Create a new colormatrix initialized with the specified colormatrix.

Parameters
src ColorMatrix

Public methods

getArray

Added in API level 1
float[] getArray ()

Return the array of floats representing this colormatrix.

Returns
float[]

postConcat

Added in API level 1
void postConcat (ColorMatrix postmatrix)

Concat this colormatrix with the specified postmatrix.

This is logically the same as calling setConcat(postmatrix, this);

Parameters
postmatrix ColorMatrix

preConcat

Added in API level 1
void preConcat (ColorMatrix prematrix)

Concat this colormatrix with the specified prematrix.

This is logically the same as calling setConcat(this, prematrix);

Parameters
prematrix ColorMatrix

reset

Added in API level 1
void reset ()

Set this colormatrix to identity:

 [ 1 0 0 0 0   - red vector
   0 1 0 0 0   - green vector
   0 0 1 0 0   - blue vector
   0 0 0 1 0 ] - alpha vector
 

set

Added in API level 1
void set (float[] src)

Assign the array of floats into this matrix, copying all of its values.

Parameters
src float

set

Added in API level 1
void set (ColorMatrix src)

Assign the src colormatrix into this matrix, copying all of its values.

Parameters
src ColorMatrix

setConcat

Added in API level 1
void setConcat (ColorMatrix matA, 
                ColorMatrix matB)

Set this colormatrix to the concatenation of the two specified colormatrices, such that the resulting colormatrix has the same effect as applying matB and then applying matA.

It is legal for either matA or matB to be the same colormatrix as this.

Parameters
matA ColorMatrix
matB ColorMatrix

setRGB2YUV

Added in API level 1
void setRGB2YUV ()

Set the matrix to convert RGB to YUV

setRotate

Added in API level 1
void setRotate (int axis, 
                float degrees)

Set the rotation on a color axis by the specified values.

axis=0 correspond to a rotation around the RED color axis=1 correspond to a rotation around the GREEN color axis=2 correspond to a rotation around the BLUE color

Parameters
axis int
degrees float

setSaturation

Added in API level 1
void setSaturation (float sat)

Set the matrix to affect the saturation of colors.

Parameters
sat float: A value of 0 maps the color to gray-scale. 1 is identity.

setScale

Added in API level 1
void setScale (float rScale, 
                float gScale, 
                float bScale, 
                float aScale)

Set this colormatrix to scale by the specified values.

Parameters
rScale float
gScale float
bScale float
aScale float

setYUV2RGB

Added in API level 1
void setYUV2RGB ()

Set the matrix to convert from YUV to RGB

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