Android APIs
public final class

DngCreator

extends Object
implements AutoCloseable
java.lang.Object
   ↳ android.hardware.camera2.DngCreator

Class Overview

The DngCreator class provides functions to write raw pixel data as a DNG file.

This class is designed to be used with the RAW_SENSOR buffers available from CameraDevice, or with Bayer-type raw pixel data that is otherwise generated by an application. The DNG metadata tags will be generated from a CaptureResult object or set directly.

The DNG file format is a cross-platform file format that is used to store pixel data from camera sensors with minimal pre-processing applied. DNG files allow for pixel data to be defined in a user-defined colorspace, and have associated metadata that allow for this pixel data to be converted to the standard CIE XYZ colorspace during post-processing.

For more information on the DNG file format and associated metadata, please refer to the Adobe DNG 1.4.0.0 specification.

Summary

Constants
int MAX_THUMBNAIL_DIMENSION Max width or height dimension for thumbnails.
Public Constructors
DngCreator(CameraCharacteristics characteristics, CaptureResult metadata)
Create a new DNG object.
Public Methods
void close()
Closes the object and release any system resources it holds.
DngCreator setDescription(String description)
Set the user description string to write.
DngCreator setLocation(Location location)
Set image location metadata.
DngCreator setOrientation(int orientation)
Set the orientation value to write.
DngCreator setThumbnail(Image pixels)
Set the thumbnail image.
DngCreator setThumbnail(Bitmap pixels)
Set the thumbnail image.
void writeByteBuffer(OutputStream dngOutput, Size size, ByteBuffer pixels, long offset)
Write the RAW_SENSOR pixel data to a DNG file with the currently configured metadata.
void writeImage(OutputStream dngOutput, Image pixels)
Write the pixel data to a DNG file with the currently configured metadata.
void writeInputStream(OutputStream dngOutput, Size size, InputStream pixels, long offset)
Write the RAW_SENSOR pixel data to a DNG file with the currently configured metadata.
Protected Methods
void finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.lang.AutoCloseable

Constants

public static final int MAX_THUMBNAIL_DIMENSION

Added in API level 21

Max width or height dimension for thumbnails.

Constant Value: 256 (0x00000100)

Public Constructors

public DngCreator (CameraCharacteristics characteristics, CaptureResult metadata)

Added in API level 21

Create a new DNG object.

It is not necessary to call any set methods to write a well-formatted DNG file.

DNG metadata tags will be generated from the corresponding parameters in the CaptureResult object.

For best quality DNG files, it is strongly recommended that lens shading map output is enabled if supported. See STATISTICS_LENS_SHADING_MAP_MODE.

Parameters
characteristics an object containing the static CameraCharacteristics.
metadata a metadata object to generate tags from.

Public Methods

public void close ()

Added in API level 21

Closes the object and release any system resources it holds.

public DngCreator setDescription (String description)

Added in API level 21

Set the user description string to write.

This is equivalent to setting the TIFF "ImageDescription" tag (0x010E).

Parameters
description the user description string.

public DngCreator setLocation (Location location)

Added in API level 21

Set image location metadata.

The given location object must contain at least a valid time, latitude, and longitude (equivalent to the values returned by getTime(), getLatitude(), and getLongitude() methods).

Parameters
location an Location object to set.
Throws
IllegalArgumentException if the given location object doesn't contain enough information to set location metadata.

public DngCreator setOrientation (int orientation)

Added in API level 21

Set the orientation value to write.

This will be written as the TIFF "Orientation" tag (0x0112). Calling this will override any prior settings for this tag.

public DngCreator setThumbnail (Image pixels)

Added in API level 21

Set the thumbnail image.

Pixel data is interpreted as a YUV_420_888 image. Thumbnail images with a dimension larger than MAX_THUMBNAIL_DIMENSION will be rejected.

Parameters
pixels an Image object with the format YUV_420_888.
Throws
IllegalArgumentException if the given thumbnail image has a dimension larger than MAX_THUMBNAIL_DIMENSION.

public DngCreator setThumbnail (Bitmap pixels)

Added in API level 21

Set the thumbnail image.

Pixel data will be converted to a Baseline TIFF RGB image, with 8 bits per color channel. The alpha channel will be discarded. Thumbnail images with a dimension larger than MAX_THUMBNAIL_DIMENSION will be rejected.

Parameters
pixels a Bitmap of pixel data.
Throws
IllegalArgumentException if the given thumbnail image has a dimension larger than MAX_THUMBNAIL_DIMENSION.

public void writeByteBuffer (OutputStream dngOutput, Size size, ByteBuffer pixels, long offset)

Added in API level 21

Write the RAW_SENSOR pixel data to a DNG file with the currently configured metadata.

Raw pixel data must have 16 bits per pixel, and the input must contain at least offset + 2 * width * height) bytes. The width and height of the input are taken from the width and height set in the DngCreator metadata tags, and will typically be equal to the width and height of SENSOR_INFO_ACTIVE_ARRAY_SIZE. The pixel layout in the input is determined from the reported color filter arrangement (CFA) set in SENSOR_INFO_COLOR_FILTER_ARRANGEMENT. If insufficient metadata is available to write a well-formatted DNG file, an IllegalStateException will be thrown.

Any mark or limit set on this ByteBuffer is ignored, and will be cleared by this method.

Parameters
dngOutput an OutputStream to write the DNG file to.
size the Size of the image to write, in pixels.
pixels an ByteBuffer of pixel data to write.
offset the offset of the raw image in bytes. This indicates how many bytes will be skipped in the input before any pixel data is read.
Throws
IOException if an error was encountered in the input or output stream.
IllegalStateException if not enough metadata information has been set to write a well-formatted DNG file.

public void writeImage (OutputStream dngOutput, Image pixels)

Added in API level 21

Write the pixel data to a DNG file with the currently configured metadata.

For this method to succeed, the Image input must contain RAW_SENSOR pixel data, otherwise an IllegalArgumentException will be thrown.

Parameters
dngOutput an OutputStream to write the DNG file to.
pixels an Image to write.
Throws
IOException if an error was encountered in the output stream.
IllegalArgumentException if an image with an unsupported format was used.
IllegalStateException if not enough metadata information has been set to write a well-formatted DNG file.

public void writeInputStream (OutputStream dngOutput, Size size, InputStream pixels, long offset)

Added in API level 21

Write the RAW_SENSOR pixel data to a DNG file with the currently configured metadata.

Raw pixel data must have 16 bits per pixel, and the input must contain at least offset + 2 * width * height) bytes. The width and height of the input are taken from the width and height set in the DngCreator metadata tags, and will typically be equal to the width and height of SENSOR_INFO_ACTIVE_ARRAY_SIZE. The pixel layout in the input is determined from the reported color filter arrangement (CFA) set in SENSOR_INFO_COLOR_FILTER_ARRANGEMENT. If insufficient metadata is available to write a well-formatted DNG file, an IllegalStateException will be thrown.

Parameters
dngOutput an OutputStream to write the DNG file to.
size the Size of the image to write, in pixels.
pixels an InputStream of pixel data to write.
offset the offset of the raw image in bytes. This indicates how many bytes will be skipped in the input before any pixel data is read.
Throws
IOException if an error was encountered in the input or output stream.
IllegalStateException if not enough metadata information has been set to write a well-formatted DNG file.
IllegalArgumentException if the size passed in does not match the

Protected Methods

protected void finalize ()

Added in API level 21

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

Throws
Throwable