/*
* @(#)JPEGImageEncoder.java 1.7 03/12/19
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
/**********************************************************************
**********************************************************************
**********************************************************************
*** COPYRIGHT (c) 1997-1998 Eastman Kodak Company. ***
*** As an unpublished work pursuant to Title 17 of the United ***
*** States Code. All rights reserved. ***
**********************************************************************
**********************************************************************
**********************************************************************/
package com.sun.image.codec.jpeg;
/**
* JPEGImageEncoder Interface
*
* JPEGImageEncoder compresses images into JPEG data streams and
* writes the JPEG stream to an OutputStream. Image data that is to
* be encoded can be passed in as a Raster of image data or as a
* BufferedImage. Encoding or the image data into the output JPEG
* stream is controlled by the parameters setting found in the
* JPEGEncodeParam object.<P>
*
* ColorSpace comments: First off JPEG by specification is color
* blind! That said, this interface will perform some color space
* conversion in the name of better compression ratios. There is no
* explicit mechanism in the JPEGEncodeParam interface for controlling
* the Encoded ColorSpace of the data when it is written to the JPEG
* data stream. If an approriate colorspace setting is not already
* defined it is recommended that colorspace unknown is used. Some
* updates to the standard color space designations have been made to
* allow this decoder to handle alpha channels. See the
* JPEGEncodeParam description for more details on additional color
* space designations ( @see JPEGEncodeParam ).<P>
*
* This encoder will process interchange, and abbreviated JPEG
* streams.
*/
import java.io.OutputStream;
import java.io.IOException;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.Raster;
/**
* JPEGImageEncoder encodes buffers of image data into JPEG data
* streams. Users of this interface are required to provide image data in
* a Raster or a BufferedImage, set the necessary parameters in the
* JPEGEncodeParams object and successfully open the
* <code>OutputStream</code> that is the destination of the encoded
* JPEG stream.
*
* The JPEGImageEncoder interface can encode image data into interchange,
* and abbreviated JPEG data streams that are written to the
* OutputStream provided to the encoder.
* <p>
* Note that the classes in the com.sun.image.codec.jpeg package are not
* part of the core Java APIs. They are a part of Sun's JDK and JRE
* distributions. Although other licensees may choose to distribute these
* classes, developers cannot depend on their availability in non-Sun
* implementations. We expect that equivalent functionality will eventually
* be available in a core API or standard extension.
* <p>
*
* @see JPEGCodec
* @see JPEGEncodeParam
* @see Raster
* @see BufferedImage
* @see OutputStream
*/
public interface JPEGImageEncoder {
/**
* Return the stream the Encoder is currenlt associated with.
*/
public OutputStream getOutputStream();
/**
* Set the JPEGEncodeParam object that is to be used for future
* encoding operations. 'jep' is copied so changes will not be
* tracked, unless you call this method again.
* @param jep The JPEGEncodeParam object to use for future encodings.
*
*/
public void setJPEGEncodeParam(JPEGEncodeParam jep);
/**
* This returns a copy of the current JPEGEncodeParam object, if
* you want changes to affect the encoding process you must 'set'
* it back into the encoder (either through setJPEGEncodeParam or
* by providing the modified param object in the call to encode.
* @return A copy of the current JPEGEncodeParam object
*/
public JPEGEncodeParam getJPEGEncodeParam();
/**
* This is a factory method for creating JPEGEncodeParam objects.
* The returned object will do a credible job of encoding the
* given BufferedImage.
*/
public JPEGEncodeParam getDefaultJPEGEncodeParam(BufferedImage bi)
throws ImageFormatException;
/**
* Encode a BufferedImage as a JPEG data stream. Note, some color
* conversions may takes place. The current JPEGEncodeParam's
* encoded COLOR_ID should match the value returned by
* getDefaultColorID when given the BufferedImage's ColorModel.<P>
* If no JPEGEncodeParam object has been provided yet a default
* one will be created by calling getDefaultJPEGEncodeParam with
* bi.
* @param bi The BufferedImage to encode.
*/
public void encode(BufferedImage bi)
throws IOException, ImageFormatException;
/**
* Encode a BufferedImage as a JPEG data stream. Note, some color
* conversions may takes place. The jep's encoded COLOR_ID should
* match the value returned by getDefaultColorID when given the
* BufferedImage's ColorModel.<P>
* This call also sets the current JPEGEncodeParam object. The
* given JPEGEncodeParam object will be used for this and future
* encodings. If jep is null then a new JPEGEncodeParam object
* will be created by calling getDefaultJPEGEncodeParam with bi.
* @param bi The BufferedImage to encode.
* @param jep The JPEGEncodeParam object used to control the encoding.
*/
public void encode(BufferedImage bi, JPEGEncodeParam jep)
throws IOException, ImageFormatException;
/**
* Returns the 'default' encoded COLOR_ID for a given ColorModel.
* This method is not needed in the simple case of encoding
* Buffered Images (the library will figure things out for you).
* It can be useful for encoding Rasters. To determine what needs
* to be done to the image prior to encoding.
* @param cm The ColorModel to map to an jpeg encoded COLOR_ID.
* @return The default mapping of cm to a jpeg Color_ID note that
* in a few cases color conversion is required.
*/
public int getDefaultColorId(ColorModel cm);
/**
* This is a factory method for creating JPEGEncodeParam objects.
* It is the users responsiblity to match the colorID with the
* data contained in the Raster. Failure to do so may lead to
* either poor compression or poor image quality. If you don't
* understand much about JPEG it is strongly reccomended that you
* stick to the BufferedImage interfaces.
*/
public JPEGEncodeParam getDefaultJPEGEncodeParam(Raster ras, int colorID)
throws ImageFormatException;
/**
* This is a factory method for creating JPEGEncodeParam objects. It
* is the users responsiblity to match the colorID with the given
* number of bands, which should match the data being encoded.
* Failure to do so may lead to poor compression and/or poor image
* quality. If you don't understand much about JPEG it is strongly
* recommended that you stick to the BufferedImage interface.
*
* @param numBands the number of bands that will be encoded (max of
* four).
* @param colorID the COLOR_ID for the encoded data. This is used to
* set reasonable defaults in the parameter object. This must match
* the number of bands given.
*/
public JPEGEncodeParam getDefaultJPEGEncodeParam(int numBands,
int colorID)
throws ImageFormatException;
/**
* This is a factory method for creating a JPEGEncodeParam from a
* JPEGDecodeParam. This will return a new JPEGEncodeParam object
* that is initialized from the JPEGDecodeParam object. All major
* pieces of information will be initialized from the DecodeParam
* (Markers, Tables, mappings).
* @param jdp The JPEGDecodeParam object to copy.
*/
public JPEGEncodeParam getDefaultJPEGEncodeParam(JPEGDecodeParam jdp)
throws ImageFormatException;
/**
* Encode a Raster as a JPEG data stream. Note that no color
* conversion takes place. It is required that you match the
* Raster to the encoded COLOR_ID contained in the current
* JPEGEncodeParam object.<P>
* If no JPEGEncodeParam object has been provided yet a
* new JPEGEncodeParam object will be created by calling
* getDefaultJPEGEncodeParam with ras and COLOR_ID_UNKNOWN.
* @param ras The Raster to encode.
*/
public void encode(Raster ras)
throws IOException, ImageFormatException;
/**
* Encode a Raster as a JPEG data stream. Note that no color
* conversion takes place. It is required that you match the
* Raster to the encoded COLOR_ID contained in the JPEGEncodeParam
* object.
* If jep is null a new JPEGEncodeParam object will be created by
* calling getDefaultJPEGEncodeParam with ras and
* COLOR_ID_UNKNOWN.
* @param ras The Raster to encode.
* @param jep The JPEGEncodeParam object used to control the encoding.
*/
public void encode(Raster ras, JPEGEncodeParam jep)
throws IOException, ImageFormatException;
}
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