org.libjpegturbo.turbojpeg

Class TJTransformer

java.lang.Object

org.libjpegturbo.turbojpeg.TJDecompressor

org.libjpegturbo.turbojpeg.TJTransformer

public class TJTransformer
extends TJDecompressor

TurboJPEG lossless transformer

Field Summary

Fields

Modifier and Type	Field and Description
private int[]	transformedSizes

Fields inherited from class org.libjpegturbo.turbojpeg.TJDecompressor

handle, jpegBuf, jpegBufSize, jpegHeight, jpegSubsamp, jpegWidth

Constructor Summary

Constructors

Constructor and Description
TJTransformer() Create a TurboJPEG lossless transformer instance.
TJTransformer(byte[] jpegImage) Create a TurboJPEG lossless transformer instance and associate the JPEG image stored in jpegImage with the newly-created instance.
TJTransformer(byte[] jpegImage, int imageSize) Create a TurboJPEG lossless transformer instance and associate the JPEG image of length imageSize bytes stored in jpegImage with the newly-created instance.

Method Summary

Modifier and Type	Method and Description
int[]	getTransformedSizes() Returns an array containing the sizes of the transformed JPEG images from the most recent call to transform().
private void	init()
void	transform(byte[][] dstBufs, TJTransform[] transforms, int flags) Losslessly transform the JPEG image associated with this transformer instance into one or more JPEG images stored in the given destination buffers.
private int[]	transform(byte[] srcBuf, int srcSize, byte[][] dstBufs, TJTransform[] transforms, int flags)
TJDecompressor[]	transform(TJTransform[] transforms, int flags) Losslessly transform the JPEG image associated with this transformer instance and return an array of TJDecompressor instances, each of which has a transformed JPEG image associated with it.

Methods inherited from class org.libjpegturbo.turbojpeg.TJDecompressor

close, decompress, decompress, decompress, decompress, decompressToYUV, decompressToYUV, finalize, getHeight, getJPEGBuf, getJPEGSize, getScaledHeight, getScaledWidth, getSubsamp, getWidth, setJPEGImage

Methods inherited from class java.lang.Object

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

Field Detail

transformedSizes

private int[] transformedSizes

Constructor Detail

TJTransformer

public TJTransformer()
              throws java.lang.Exception

Create a TurboJPEG lossless transformer instance.

Throws:

java.lang.Exception

TJTransformer

public TJTransformer(byte[] jpegImage)
              throws java.lang.Exception

Create a TurboJPEG lossless transformer instance and associate the JPEG image stored in jpegImage with the newly-created instance.

Parameters:

jpegImage - JPEG image buffer (size of the JPEG image is assumed to be the length of the array)

Throws:

java.lang.Exception

TJTransformer

public TJTransformer(byte[] jpegImage,
                     int imageSize)
              throws java.lang.Exception

Create a TurboJPEG lossless transformer instance and associate the JPEG image of length imageSize bytes stored in jpegImage with the newly-created instance.

Parameters:

jpegImage - JPEG image buffer

imageSize - size of the JPEG image (in bytes)

Throws:

java.lang.Exception

Method Detail

transform

public void transform(byte[][] dstBufs,
                      TJTransform[] transforms,
                      int flags)
               throws java.lang.Exception

Losslessly transform the JPEG image associated with this transformer instance into one or more JPEG images stored in the given destination buffers. Lossless transforms work by moving the raw coefficients from one JPEG image structure to another without altering the values of the coefficients. While this is typically faster than decompressing the image, transforming it, and re-compressing it, lossless transforms are not free. Each lossless transform requires reading and Huffman decoding all of the coefficients in the source image, regardless of the size of the destination image. Thus, this method provides a means of generating multiple transformed images from the same source or of applying multiple transformations simultaneously, in order to eliminate the need to read the source coefficients multiple times.

Parameters:

dstBufs - an array of image buffers. dstbufs[i] will receive a JPEG image that has been transformed using the parameters in transforms[i]. Use TJ.bufSize(int, int, int) to determine the maximum size for each buffer based on the cropped width and height.

transforms - an array of TJTransform instances, each of which specifies the transform parameters and/or cropping region for the corresponding transformed output image

flags - the bitwise OR of one or more of TJ.FLAG_*

Throws:

java.lang.Exception

transform

public TJDecompressor[] transform(TJTransform[] transforms,
                                  int flags)
                           throws java.lang.Exception

Losslessly transform the JPEG image associated with this transformer instance and return an array of TJDecompressor instances, each of which has a transformed JPEG image associated with it.

Parameters:

transforms - an array of TJTransform instances, each of which specifies the transform parameters and/or cropping region for the corresponding transformed output image

flags - the bitwise OR of one or more of TJ.FLAG_*

Returns:

an array of TJDecompressor instances, each of which has a transformed JPEG image associated with it

Throws:

java.lang.Exception

getTransformedSizes

public int[] getTransformedSizes()
                          throws java.lang.Exception

Returns an array containing the sizes of the transformed JPEG images from the most recent call to transform().

Returns:

an array containing the sizes of the transformed JPEG images from the most recent call to transform()

Throws:

java.lang.Exception

init

private void init()
           throws java.lang.Exception

Throws:

java.lang.Exception

transform

private int[] transform(byte[] srcBuf,
                        int srcSize,
                        byte[][] dstBufs,
                        TJTransform[] transforms,
                        int flags)
                 throws java.lang.Exception

Throws:

java.lang.Exception