Added in API level 1

Summary: Ctors | Methods | Inherited Methods

ColorMatrix

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Kotlin |Java

public class ColorMatrix
extends Object

java.lang.Object
↳	android.graphics.ColorMatrix

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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(ColorMatrix src) Create a new colormatrix initialized with the specified colormatrix.
ColorMatrix(float[] src) Create a new colormatrix initialized with the specified array of values.

Public methods
boolean	equals(Object obj) Indicates whether some other object is "equal to" this one.
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 Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public constructors

ColorMatrix

Added in API level 1

public ColorMatrix ()

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

ColorMatrix

Added in API level 1

public ColorMatrix (ColorMatrix src)

Create a new colormatrix initialized with the specified colormatrix.

Parameters
src	ColorMatrix

ColorMatrix

Added in API level 1

public ColorMatrix (float[] src)

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

Parameters
src	float

Public methods

equals

Added in API level 1

public boolean equals (Object obj)

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters
obj	Object: the reference object with which to compare.

Returns
boolean	true if this object is the same as the obj argument; false otherwise.

getArray

Added in API level 1

public final float[] getArray ()

Return the array of floats representing this colormatrix.

Returns
float[]

postConcat

Added in API level 1

public 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

public 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

public 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

public 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

public 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

public 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

public void setRGB2YUV ()

Set the matrix to convert RGB to YUV

setRotate

Added in API level 1

public 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

public 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

public 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

public void setYUV2RGB ()

Set the matrix to convert from YUV to RGB