Added in API level 1

Summary: Enums | Methods | Inherited Methods

PorterDuff.Mode

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Kotlin |Java

public static final enum PorterDuff.Mode
extends Enum<PorterDuff.Mode>

java.lang.Object
↳	java.lang.Enum<android.graphics.PorterDuff.Mode>
	↳	android.graphics.PorterDuff.Mode

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The name of the parent class is an homage to the work of Thomas Porter and Tom Duff, presented in their seminal 1984 paper titled "Compositing Digital Images". In this paper, the authors describe 12 compositing operators that govern how to compute the color resulting of the composition of a source (the graphics object to render) with a destination (the content of the render target).

"Compositing Digital Images" was published in Computer Graphics Volume 18, Number 3 dated July 1984.

Because the work of Porter and Duff focuses solely on the effects of the alpha channel of the source and destination, the 12 operators described in the original paper are called alpha compositing modes here.

For convenience, this class also provides several blending modes, which similarly define the result of compositing a source and a destination but without being constrained to the alpha channel. These blending modes are not defined by Porter and Duff but have been included in this class for convenience purposes.

Diagrams

All the example diagrams presented below use the same source and destination images:

Source image

Destination image

The order of drawing operations used to generate each diagram is shown in the following code snippet:

 Paint paint = new Paint();
 canvas.drawBitmap(destinationImage, 0, 0, paint);

 PorterDuff.Mode mode = // choose a mode
 paint.setXfermode(new PorterDuffXfermode(mode));

 canvas.drawBitmap(sourceImage, 0, 0, paint);
 

Alpha compositing modes

Source	Source Over	Source In	Source Atop
Destination	Destination Over	Destination In	Destination Atop
Clear	Source Out	Destination Out	Exclusive Or

Blending modes

Darken	Lighten	Multiply
Screen	Overlay

Compositing equations

The documentation of each individual alpha compositing or blending mode below provides the exact equation used to compute alpha and color value of the result of the composition of a source and destination.

The result (or output) alpha value is noted \(\alpha_{out}\). The result (or output) color value is noted \(C_{out}\).

Summary

Enum values
PorterDuff.Mode	ADD Adds the source pixels to the destination pixels and saturates the result.
PorterDuff.Mode	CLEAR Destination pixels covered by the source are cleared to 0.
PorterDuff.Mode	DARKEN Retains the smallest component of the source and destination pixels.
PorterDuff.Mode	DST The source pixels are discarded, leaving the destination intact.
PorterDuff.Mode	DST_ATOP Discards the destination pixels that are not covered by source pixels.
PorterDuff.Mode	DST_IN Keeps the destination pixels that cover source pixels, discards the remaining source and destination pixels.
PorterDuff.Mode	DST_OUT Keeps the destination pixels that are not covered by source pixels.
PorterDuff.Mode	DST_OVER The source pixels are drawn behind the destination pixels.
PorterDuff.Mode	LIGHTEN Retains the largest component of the source and destination pixel.
PorterDuff.Mode	MULTIPLY Multiplies the source and destination pixels.
PorterDuff.Mode	OVERLAY Multiplies or screens the source and destination depending on the destination color.
PorterDuff.Mode	SCREEN Adds the source and destination pixels, then subtracts the source pixels multiplied by the destination.
PorterDuff.Mode	SRC The source pixels replace the destination pixels.
PorterDuff.Mode	SRC_ATOP Discards the source pixels that do not cover destination pixels.
PorterDuff.Mode	SRC_IN Keeps the source pixels that cover the destination pixels, discards the remaining source and destination pixels.
PorterDuff.Mode	SRC_OUT Keeps the source pixels that do not cover destination pixels.
PorterDuff.Mode	SRC_OVER The source pixels are drawn over the destination pixels.
PorterDuff.Mode	XOR Discards the source and destination pixels where source pixels cover destination pixels.

Public methods
static PorterDuff.Mode	valueOf(String name)
static final Mode[]	values()

Inherited methods
From class java.lang.Enum final Object clone() Throws CloneNotSupportedException. final int compareTo(E o) Compares this enum with the specified object for order. final boolean equals(Object other) Returns true if the specified object is equal to this enum constant. final void finalize() enum classes cannot have finalize methods. final Class<E> getDeclaringClass() Returns the Class object corresponding to this enum constant's enum type. final int hashCode() Returns a hash code for this enum constant. final String name() Returns the name of this enum constant, exactly as declared in its enum declaration. final int ordinal() Returns the ordinal of this enumeration constant (its position in its enum declaration, where the initial constant is assigned an ordinal of zero). String toString() Returns the name of this enum constant, as contained in the declaration. static <T extends Enum<T>> T valueOf(Class<T> enumClass, String name) Returns the enum constant of the specified enum class with the specified name.
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.
From interface java.lang.Comparable abstract int compareTo(E o) Compares this object with the specified object for order.

Enum values

ADD

Added in API level 11

public static final PorterDuff.Mode ADD

Adds the source pixels to the destination pixels and saturates the result.

\(\alpha_{out} = max(0, min(\alpha_{src} + \alpha_{dst}, 1))\)

\(C_{out} = max(0, min(C_{src} + C_{dst}, 1))\)

CLEAR

Added in API level 1

public static final PorterDuff.Mode CLEAR

Destination pixels covered by the source are cleared to 0.

\(\alpha_{out} = 0\)

\(C_{out} = 0\)

DARKEN

Added in API level 1

public static final PorterDuff.Mode DARKEN

Retains the smallest component of the source and destination pixels.

\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)

\(C_{out} = (1 - \alpha_{dst}) * C_{src} + (1 - \alpha_{src}) * C_{dst} + min(C_{src}, C_{dst})\)

DST

Added in API level 1

public static final PorterDuff.Mode DST

The source pixels are discarded, leaving the destination intact.

\(\alpha_{out} = \alpha_{dst}\)

\(C_{out} = C_{dst}\)

DST_ATOP

Added in API level 1

public static final PorterDuff.Mode DST_ATOP

Discards the destination pixels that are not covered by source pixels. Draws remaining destination pixels over source pixels.

\(\alpha_{out} = \alpha_{src}\)

\(C_{out} = \alpha_{src} * C_{dst} + (1 - \alpha_{dst}) * C_{src}\)

DST_IN

Added in API level 1

public static final PorterDuff.Mode DST_IN

Keeps the destination pixels that cover source pixels, discards the remaining source and destination pixels.

\(\alpha_{out} = \alpha_{src} * \alpha_{dst}\)

\(C_{out} = C_{dst} * \alpha_{src}\)

DST_OUT

Added in API level 1

public static final PorterDuff.Mode DST_OUT

Keeps the destination pixels that are not covered by source pixels. Discards destination pixels that are covered by source pixels. Discards all source pixels.

\(\alpha_{out} = (1 - \alpha_{src}) * \alpha_{dst}\)

\(C_{out} = (1 - \alpha_{src}) * C_{dst}\)

DST_OVER

Added in API level 1

public static final PorterDuff.Mode DST_OVER

The source pixels are drawn behind the destination pixels.

\(\alpha_{out} = \alpha_{dst} + (1 - \alpha_{dst}) * \alpha_{src}\)

\(C_{out} = C_{dst} + (1 - \alpha_{dst}) * C_{src}\)

LIGHTEN

Added in API level 1

public static final PorterDuff.Mode LIGHTEN

Retains the largest component of the source and destination pixel.

\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)

\(C_{out} = (1 - \alpha_{dst}) * C_{src} + (1 - \alpha_{src}) * C_{dst} + max(C_{src}, C_{dst})\)

MULTIPLY

Added in API level 1

public static final PorterDuff.Mode MULTIPLY

Multiplies the source and destination pixels.

\(\alpha_{out} = \alpha_{src} * \alpha_{dst}\)

\(C_{out} = C_{src} * C_{dst}\)

OVERLAY

Added in API level 11

public static final PorterDuff.Mode OVERLAY

Multiplies or screens the source and destination depending on the destination color.

\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)

\(\begin{equation} C_{out} = \begin{cases} 2 * C_{src} * C_{dst} & 2 * C_{dst} \lt \alpha_{dst} \\ \alpha_{src} * \alpha_{dst} - 2 (\alpha_{dst} - C_{src}) (\alpha_{src} - C_{dst}) & otherwise \end{cases} \end{equation}\)

SCREEN

Added in API level 1

public static final PorterDuff.Mode SCREEN

Adds the source and destination pixels, then subtracts the source pixels multiplied by the destination.

\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)

\(C_{out} = C_{src} + C_{dst} - C_{src} * C_{dst}\)

SRC

Added in API level 1

public static final PorterDuff.Mode SRC

The source pixels replace the destination pixels.

\(\alpha_{out} = \alpha_{src}\)

\(C_{out} = C_{src}\)

SRC_ATOP

Added in API level 1

public static final PorterDuff.Mode SRC_ATOP

Discards the source pixels that do not cover destination pixels. Draws remaining source pixels over destination pixels.

\(\alpha_{out} = \alpha_{dst}\)

\(C_{out} = \alpha_{dst} * C_{src} + (1 - \alpha_{src}) * C_{dst}\)

SRC_IN

Added in API level 1

public static final PorterDuff.Mode SRC_IN

Keeps the source pixels that cover the destination pixels, discards the remaining source and destination pixels.

\(\alpha_{out} = \alpha_{src} * \alpha_{dst}\)

\(C_{out} = C_{src} * \alpha_{dst}\)

SRC_OUT

Added in API level 1

public static final PorterDuff.Mode SRC_OUT

Keeps the source pixels that do not cover destination pixels. Discards source pixels that cover destination pixels. Discards all destination pixels.

\(\alpha_{out} = (1 - \alpha_{dst}) * \alpha_{src}\)

\(C_{out} = (1 - \alpha_{dst}) * C_{src}\)

SRC_OVER

Added in API level 1

public static final PorterDuff.Mode SRC_OVER

The source pixels are drawn over the destination pixels.

\(\alpha_{out} = \alpha_{src} + (1 - \alpha_{src}) * \alpha_{dst}\)

\(C_{out} = C_{src} + (1 - \alpha_{src}) * C_{dst}\)

XOR

Added in API level 1

public static final PorterDuff.Mode XOR

Discards the source and destination pixels where source pixels cover destination pixels. Draws remaining source pixels.

\(\alpha_{out} = (1 - \alpha_{dst}) * \alpha_{src} + (1 - \alpha_{src}) * \alpha_{dst}\)

\(C_{out} = (1 - \alpha_{dst}) * C_{src} + (1 - \alpha_{src}) * C_{dst}\)

Public methods

valueOf

public static PorterDuff.Mode valueOf (String name)

Parameters
name	String

Returns
PorterDuff.Mode

values

public static final Mode[] values ()

Returns
Mode[]