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 | |
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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 | |
---|---|
Public constructors
ColorMatrix
public ColorMatrix ()
Create a new colormatrix initialized to identity (as if reset() had been called).
ColorMatrix
public ColorMatrix (float[] src)
Create a new colormatrix initialized with the specified array of values.
Parameters | |
---|---|
src |
float |
ColorMatrix
public ColorMatrix (ColorMatrix src)
Create a new colormatrix initialized with the specified colormatrix.
Parameters | |
---|---|
src |
ColorMatrix |
Public methods
equals
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 returntrue
. - It is symmetric: for any non-null reference values
x
andy
,x.equals(y)
should returntrue
if and only ify.equals(x)
returnstrue
. - It is transitive: for any non-null reference values
x
,y
, andz
, ifx.equals(y)
returnstrue
andy.equals(z)
returnstrue
, thenx.equals(z)
should returntrue
. - It is consistent: for any non-null reference values
x
andy
, multiple invocations ofx.equals(y)
consistently returntrue
or consistently returnfalse
, provided no information used inequals
comparisons on the objects is modified. - For any non-null reference value
x
,x.equals(null)
should returnfalse
.
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 | |
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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
public final float[] getArray ()
Return the array of floats representing this colormatrix.
Returns | |
---|---|
float[] |
postConcat
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
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
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
public void set (float[] src)
Assign the array of floats into this matrix, copying all of its values.
Parameters | |
---|---|
src |
float |
set
public void set (ColorMatrix src)
Assign the src colormatrix into this matrix, copying all of its values.
Parameters | |
---|---|
src |
ColorMatrix |
setConcat
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 |
setRotate
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
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
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 |