Package de.digitalcollections.turbojpeg

Class TurboJpeg

java.lang.Object

de.digitalcollections.turbojpeg.TurboJpeg

public class TurboJpeg
extends Object

Java bindings for libturbojpeg via JFFI *

Field Summary

Fields

Modifier and Type	Field	Description
libturbojpeg	lib
jnr.ffi.Runtime	runtime

Constructor Summary

Constructors

Constructor	Description
TurboJpeg()

Method Summary

Modifier and Type	Method	Description
BufferedImage	decode(byte[] jpegData, Info info, Dimension size)	Decode the JPEG image in the input buffer into a BufferedImage.
ByteBuffer	encode(Raster img, int quality)	Encode an image to JPEG
Info	getInfo(byte[] jpegData)	Return information about the JPEG image in the input buffer
ByteBuffer	transform(byte[] jpegData, Info info, Rectangle region, int rotation)	Transform a JPEG image without decoding it fully

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

lib

public libturbojpeg lib

runtime

public jnr.ffi.Runtime runtime

Constructor Detail

TurboJpeg

public TurboJpeg()

Method Detail

getInfo

public Info getInfo(byte[] jpegData)
             throws TurboJpegException

Return information about the JPEG image in the input buffer

Parameters:

jpegData - jpeg image data

Returns:

information about the jpeg image

Throws:

TurboJpegException - if decompressing header with library fails

decode

public BufferedImage decode(byte[] jpegData,
                            Info info,
                            Dimension size)
                     throws TurboJpegException

Decode the JPEG image in the input buffer into a BufferedImage.

Parameters:

jpegData - JPEG data input buffer

info - Information about the JPEG image in the buffer

size - Target decompressed dimensions, must be among the available sizes (see Info.getAvailableSizes())

Returns:

The decoded image

Throws:

TurboJpegException - if decompression with library fails

encode

public ByteBuffer encode(Raster img,
                         int quality)
                  throws TurboJpegException

Encode an image to JPEG

Parameters:

img - image as rectangle of pixels

quality - compression quality

Returns:

jpeg image

Throws:

TurboJpegException - if compression with library fails

transform

public ByteBuffer transform(byte[] jpegData,
                            Info info,
                            Rectangle region,
                            int rotation)
                     throws TurboJpegException

Transform a JPEG image without decoding it fully

Parameters:

jpegData - JPEG input buffer

info - Information about the JPEG (from getInfo(byte[])

region - Source region to crop out of JPEG

rotation - Degrees to rotate the JPEG, must be 90, 180 or 270

Returns:

The transformed JPEG data

Throws:

TurboJpegException - if image transformation fails