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ColorSpaceTransform

public final class ColorSpaceTransform
extends Object

java.lang.Object
   ↳ android.hardware.camera2.params.ColorSpaceTransform


Immutable class for describing a 3x3 matrix of Rational values in row-major order.

This matrix maps a transform from one color space to another. For the particular color space source and target, see the appropriate camera metadata documentation for the key that provides this value.

See also:

Summary

Public constructors

ColorSpaceTransform(Rational[] elements)

Create a new immutable ColorSpaceTransform instance from a Rational array.

ColorSpaceTransform(int[] elements)

Create a new immutable ColorSpaceTransform instance from an int array.

Public methods

void copyElements(int[] destination, int offset)

Copy the Rational elements in row-major order from this matrix into the destination.

void copyElements(Rational[] destination, int offset)

Copy the Rational elements in row-major order from this matrix into the destination.

boolean equals(Object obj)

Check if this ColorSpaceTransform is equal to another ColorSpaceTransform.

Rational getElement(int column, int row)

Get an element of this matrix by its row and column.

int hashCode()

Returns a hash code value for the object.

String toString()

Return the color space transform as a string representation.

Inherited methods

Public constructors

ColorSpaceTransform

added in API level 21
public ColorSpaceTransform (Rational[] elements)

Create a new immutable ColorSpaceTransform instance from a Rational array.

The elements must be stored in a row-major order.

Parameters
elements Rational: An array of 9 elements

Throws
IllegalArgumentException if the count of elements is not 9
NullPointerException if elements or any sub-element is null

ColorSpaceTransform

added in API level 21
public ColorSpaceTransform (int[] elements)

Create a new immutable ColorSpaceTransform instance from an int array.

The elements must be stored in a row-major order. Each rational is stored contiguously as a (numerator, denominator) pair.

In particular:

int[] elements = new int[
     N11, D11, N12, D12, N13, D13,
     N21, D21, N22, D22, N23, D23,
     N31, D31, N32, D32, N33, D33
 ];

 new ColorSpaceTransform(elements)
where Nij and Dij is the numerator and denominator for row i and column j.

Parameters
elements int: An array of 18 elements

Throws
IllegalArgumentException if the count of elements is not 18
NullPointerException if elements is null

Public methods

copyElements

added in API level 21
public void copyElements (int[] destination, 
                int offset)

Copy the Rational elements in row-major order from this matrix into the destination.

Each element is stored as a contiguous rational packed as a (numerator, denominator) pair of ints, identical to the constructor.

Parameters
destination int: an array big enough to hold at least 18 elements after the offset

offset int: a non-negative offset into the array

Throws
NullPointerException If destination was null
ArrayIndexOutOfBoundsException If there's not enough room to write the elements at the specified destination and offset.

copyElements

added in API level 21
public void copyElements (Rational[] destination, 
                int offset)

Copy the Rational elements in row-major order from this matrix into the destination.

Parameters
destination Rational: an array big enough to hold at least 9 elements after the offset

offset int: a non-negative offset into the array

Throws
NullPointerException If destination was null
ArrayIndexOutOfBoundsException If there's not enough room to write the elements at the specified destination and offset.

equals

added in API level 21
public boolean equals (Object obj)

Check if this ColorSpaceTransform is equal to another ColorSpaceTransform.

Two color space transforms are equal if and only if all of their elements are equal.

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

Returns
boolean true if the objects were equal, false otherwise

getElement

added in API level 21
public Rational getElement (int column, 
                int row)

Get an element of this matrix by its row and column.

The rows must be within the range [0, 3), and the column must be within the range [0, 3).

Parameters
column int

row int

Returns
Rational element (non-null)

Throws
IllegalArgumentException if column or row was out of range

hashCode

added in API level 21
public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)

Returns
int a hash code value for this object.

toString

added in API level 21
public String toString ()

Return the color space transform as a string representation.

Example: "ColorSpaceTransform([1/1, 0/1, 0/1], [0/1, 1/1, 0/1], [0/1, 0/1, 1/1])" is an identity transform. Elements are printed in row major order.

Returns
String string representation of color space transform