Added in API level 10

Summary: Methods | Protected Methods | Inherited Methods

BitmapRegionDecoder

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Kotlin |Java

public final class BitmapRegionDecoder
extends Object

java.lang.Object
↳	android.graphics.BitmapRegionDecoder

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BitmapRegionDecoder can be used to decode a rectangle region from an image. BitmapRegionDecoder is particularly useful when an original image is large and you only need parts of the image.

To create a BitmapRegionDecoder, call newInstance(...). Given a BitmapRegionDecoder, users can call decodeRegion() repeatedly to get a decoded Bitmap of the specified region.

Summary

Public methods
Bitmap	decodeRegion(Rect rect, BitmapFactory.Options options) Decodes a rectangle region in the image specified by rect.
int	getHeight() Returns the original image's height
int	getWidth() Returns the original image's width
boolean	isRecycled() Returns true if this region decoder has been recycled.
static BitmapRegionDecoder	newInstance(byte[] data, int offset, int length) Create a BitmapRegionDecoder from the specified byte array.
static BitmapRegionDecoder	newInstance(String pathName, boolean isShareable) This method was deprecated in API level 31. In favor of newInstance(java.lang.String)
static BitmapRegionDecoder	newInstance(byte[] data, int offset, int length, boolean isShareable) This method was deprecated in API level 31. In favor of newInstance(byte[], int, int)
static BitmapRegionDecoder	newInstance(ParcelFileDescriptor pfd) Create a BitmapRegionDecoder from the file descriptor.
static BitmapRegionDecoder	newInstance(InputStream is) Create a BitmapRegionDecoder from an input stream.
static BitmapRegionDecoder	newInstance(InputStream is, boolean isShareable) This method was deprecated in API level 31. In favor of newInstance(java.io.InputStream) Prior to Build.VERSION_CODES#KITKAT, if is.markSupported() returns true, is.mark(1024) would be called. As of Build.VERSION_CODES#KITKAT, this is no longer the case.
static BitmapRegionDecoder	newInstance(FileDescriptor fd, boolean isShareable) This method was deprecated in API level 31. In favor of newInstance(android.os.ParcelFileDescriptor)
static BitmapRegionDecoder	newInstance(String pathName) Create a BitmapRegionDecoder from a file path.
void	recycle() Frees up the memory associated with this region decoder, and mark the region decoder as "dead", meaning it will throw an exception if decodeRegion(), getWidth() or getHeight() is called.

Protected methods
void	finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

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 methods

decodeRegion

Added in API level 10

public Bitmap decodeRegion (Rect rect, 
                BitmapFactory.Options options)

Decodes a rectangle region in the image specified by rect.

Parameters
rect	Rect: The rectangle that specified the region to be decode.
options	BitmapFactory.Options: null-ok; Options that control downsampling. inPurgeable is not supported.

Returns
Bitmap	The decoded bitmap, or null if the image data could not be decoded.

Throws
IllegalArgumentException	if BitmapFactory.Options#inPreferredConfig is Bitmap.Config.HARDWARE and BitmapFactory.Options#inMutable is set, if the specified color space is not RGB, or if the specified color space's transfer function is not an ICC parametric curve

getHeight

Added in API level 10

public int getHeight ()

Returns the original image's height

Returns
int

getWidth

Added in API level 10

public int getWidth ()

Returns the original image's width

Returns
int

isRecycled

Added in API level 10

public boolean isRecycled ()

Returns true if this region decoder has been recycled. If so, then it is an error to try use its method.

Returns
boolean	true if the region decoder has been recycled

newInstance

Added in API level 31

public static BitmapRegionDecoder newInstance (byte[] data, 
                int offset, 
                int length)

Create a BitmapRegionDecoder from the specified byte array. Currently only the JPEG, PNG, WebP and HEIF formats are supported.

Parameters
data	byte: byte array of compressed image data. This value cannot be null.
offset	int: offset into data for where the decoder should begin parsing.
length	int: the number of bytes, beginning at offset, to parse

Returns
BitmapRegionDecoder	This value cannot be null.

Throws
IOException	if the image format is not supported or can not be decoded.

newInstance

Added in API level 10
Deprecated in API level 31

public static BitmapRegionDecoder newInstance (String pathName, 
                boolean isShareable)

This method was deprecated in API level 31.
In favor of newInstance(java.lang.String)

Create a BitmapRegionDecoder from a file path. Currently only the JPEG, PNG, WebP and HEIF formats are supported.

Parameters
pathName	String: complete path name for the file to be decoded. This value cannot be null.
isShareable	boolean: This field has always been ignored.

Returns
BitmapRegionDecoder	This value cannot be null.

Throws
IOException	if the image format is not supported or can not be decoded.

newInstance

Added in API level 10
Deprecated in API level 31

public static BitmapRegionDecoder newInstance (byte[] data, 
                int offset, 
                int length, 
                boolean isShareable)

This method was deprecated in API level 31.
In favor of newInstance(byte[], int, int)

Create a BitmapRegionDecoder from the specified byte array. Currently only the JPEG, PNG, WebP and HEIF formats are supported.

Parameters
data	byte: byte array of compressed image data. This value cannot be null.
offset	int: offset into data for where the decoder should begin parsing.
length	int: the number of bytes, beginning at offset, to parse
isShareable	boolean: This field has been ignored since Build.VERSION_CODES#GINGERBREAD.

Returns
BitmapRegionDecoder	This value cannot be null.

Throws
IOException	if the image format is not supported or can not be decoded.

newInstance

Added in API level 31

public static BitmapRegionDecoder newInstance (ParcelFileDescriptor pfd)

Create a BitmapRegionDecoder from the file descriptor. The position within the descriptor will not be changed when this returns, so the descriptor can be used again as is. Currently only the JPEG, PNG, WebP and HEIF formats are supported.

Parameters
pfd	ParcelFileDescriptor: The parcel file descriptor containing the data to decode This value cannot be null.

Returns
BitmapRegionDecoder	This value cannot be null.

Throws
IOException	if the image format is not supported or can not be decoded.

newInstance

Added in API level 31

public static BitmapRegionDecoder newInstance (InputStream is)

Create a BitmapRegionDecoder from an input stream. The stream's position will be where ever it was after the encoded data was read. Currently only the JPEG, PNG, WebP and HEIF formats are supported.

Parameters
is	InputStream: The input stream that holds the raw data to be decoded into a BitmapRegionDecoder. This value cannot be null.

Returns
BitmapRegionDecoder	A new BitmapRegionDecoder, or null if is is null.

Throws
IOException	if the image format is not supported or can not be decoded.

newInstance

Added in API level 10
Deprecated in API level 31

public static BitmapRegionDecoder newInstance (InputStream is, 
                boolean isShareable)

This method was deprecated in API level 31.
In favor of newInstance(java.io.InputStream)

Prior to Build.VERSION_CODES#KITKAT, if is.markSupported() returns true, is.mark(1024) would be called. As of Build.VERSION_CODES#KITKAT, this is no longer the case.

Create a BitmapRegionDecoder from an input stream. The stream's position will be where ever it was after the encoded data was read. Currently only the JPEG, PNG, WebP and HEIF formats are supported.

Parameters
is	InputStream: The input stream that holds the raw data to be decoded into a BitmapRegionDecoder. This value cannot be null.
isShareable	boolean: This field has always been ignored.

Returns
BitmapRegionDecoder	A new BitmapRegionDecoder, or null if is is null.

Throws
IOException	if the image format is not supported or can not be decoded.

newInstance

Added in API level 10
Deprecated in API level 31

public static BitmapRegionDecoder newInstance (FileDescriptor fd, 
                boolean isShareable)

This method was deprecated in API level 31.
In favor of newInstance(android.os.ParcelFileDescriptor)

Create a BitmapRegionDecoder from the file descriptor. The position within the descriptor will not be changed when this returns, so the descriptor can be used again as is. Currently only the JPEG, PNG, WebP and HEIF formats are supported.

Parameters
fd	FileDescriptor: The file descriptor containing the data to decode This value cannot be null.
isShareable	boolean: This field has been ignored since Build.VERSION_CODES#KITKAT.

Returns
BitmapRegionDecoder	This value cannot be null.

Throws
IOException	if the image format is not supported or can not be decoded.

newInstance

Added in API level 31

public static BitmapRegionDecoder newInstance (String pathName)

Create a BitmapRegionDecoder from a file path. Currently only the JPEG, PNG, WebP and HEIF formats are supported.

Parameters
pathName	String: complete path name for the file to be decoded. This value cannot be null.

Returns
BitmapRegionDecoder	This value cannot be null.

Throws
IOException	if the image format is not supported or can not be decoded.

recycle

Added in API level 10

public void recycle ()

Frees up the memory associated with this region decoder, and mark the region decoder as "dead", meaning it will throw an exception if decodeRegion(), getWidth() or getHeight() is called.

This operation cannot be reversed, so it should only be called if you are sure there are no further uses for the region decoder. This is an advanced call, and normally need not be called, since the normal GC process will free up this memory when there are no more references to this region decoder.

Protected methods

finalize

Added in API level 10

protected void finalize ()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.

The general contract of finalize is that it is invoked if and when the Java virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.

The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.

The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.

After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object.

Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.

Throws
Throwable