org.libjpegturbo.turbojpeg

Class TJTransformer

java.lang.Object

org.libjpegturbo.turbojpeg.TJDecompressor

org.libjpegturbo.turbojpeg.TJTransformer

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class TJTransformer
extends TJDecompressor

TurboJPEG lossless transformer

Field Summary

Fields inherited from class org.libjpegturbo.turbojpeg.TJDecompressor

handle, jpegBuf, jpegBufSize, jpegColorspace, jpegHeight, jpegSubsamp, jpegWidth, yuvImage

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 source image stored in jpegImage with the newly created instance.
TJTransformer(byte[] jpegImage, int imageSize) Create a TurboJPEG lossless transformer instance and associate the JPEG source 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 (in bytes) generated by the most recent transform operation.
void	transform(byte[][] dstBufs, TJTransform[] transforms, int flags) Losslessly transform the JPEG source image associated with this transformer instance into one or more JPEG images stored in the given destination buffers.
TJDecompressor[]	transform(TJTransform[] transforms, int flags) Losslessly transform the JPEG source 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, decompress, decompress, decompressToYUV, decompressToYUV, decompressToYUV, decompressToYUV, decompressToYUV, finalize, getColorspace, getHeight, getJPEGBuf, getJPEGSize, getScaledHeight, getScaledWidth, getSubsamp, getWidth, setJPEGImage, setSourceImage, setSourceImage

Methods inherited from class java.lang.Object

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

Constructor Detail

TJTransformer

public TJTransformer()
              throws TJException

Create a TurboJPEG lossless transformer instance.

Throws:

TJException

TJTransformer

public TJTransformer(byte[] jpegImage)
              throws TJException

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

Parameters:

jpegImage - buffer containing the JPEG source image to transform. (The size of the JPEG image is assumed to be the length of the array.) This buffer is not modified.

Throws:

TJException

TJTransformer

public TJTransformer(byte[] jpegImage,
                     int imageSize)
              throws TJException

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

Parameters:

jpegImage - buffer containing the JPEG source image to transform. This buffer is not modified.

imageSize - size of the JPEG source image (in bytes)

Throws:

TJException

Method Detail

transform

public void transform(byte[][] dstBufs,
                      TJTransform[] transforms,
                      int flags)
               throws TJException

Losslessly transform the JPEG source 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 performing Huffman decoding on 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 JPEG destination 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 transformed or cropped width and height and the level of subsampling used in the destination image (taking into account grayscale conversion and transposition of the width and height.)

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

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

Throws:

TJException

transform

public TJDecompressor[] transform(TJTransform[] transforms,
                                  int flags)
                           throws TJException

Losslessly transform the JPEG source 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 JPEG 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:

TJException

getTransformedSizes

public int[] getTransformedSizes()

Returns an array containing the sizes of the transformed JPEG images (in bytes) generated by the most recent transform operation.

Returns:

an array containing the sizes of the transformed JPEG images (in bytes) generated by the most recent transform operation.