/*
* @(#)JPEGEncodeParam.java 1.8 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*** As an unpublished work pursuant to Title 17 of the United ***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;
/**
* JPEGEncodeParam encapsulates tables and options necessary to
* control encoding of JPEG data streams. Parameters are either set
* explicitly by the application for encoding, or read from another
* JPEG header.<p>
* When working with BufferedImages, the codec will attempt to match
* the encoded JPEG COLOR_ID with the ColorModel in the BufferedImage.
* This is not always possible (the default mappings are listed
* below). In cases where unsupported conversions are required (or
* odd image colorspaces are in use) the user must either convert the
* image data to a known ColorSpace or encode the data from a raster.
* When encoding rasters no colorspace adjustments are made, so the
* user must do any conversions required to get to the encoded
* COLOR_ID.
* The COLOR_ID for the encoded images is used to control the JPEG
* codec's inital values for Huffman and Quantization Tables as well
* as subsampling factors. It is also used to determine what color
* conversion should be performed to obtain the best encoding.<p>
* Note: The color ids described herein are simply enumerated values
* that influence data processing by the JPEG codec. JPEG compression
* is, by definition, color blind. These values are used as hints when
* compressing JPEG data. Through these values the JPEG codec can
* perform some default rotation of data into spaces that will aid in
* getting better compression ratios.<P>
* Example behaviour is described below. Since these mappings are
* likely to change in the future it is strongly recommended that you
* make use of the @see JPEGImageEncoder.getDefaultParamBlock calls
* and check the encodedColorID for your particular BufferedImage.
* In extreme cases is may be necessary for the user to convert the
* image to the desired colorspace, and encode it from a Raster. In
* this case the API programmer must specify the colorID of the data
* in the Raster and no color conversion will take place.
<pre>
ENCODING:
BufferedImage Type/Instance JPEG (Encoded) Color ID
======================== =======================
TYPE_GRAY COLOR_ID_GRAYSCALE
TYPE_RGB COLOR_ID_YCbCr
TYPE_YCbCr COLOR_ID_YCbCr
TYPE_YCbCr/CS_PYCC COLOR_ID_PYCC
TYPE_CMYK COLOR_ID_CMYK
TYPE_RGB (w/ alpha) COLOR_ID_YCbCrA
TYPE_YCbCr (w/ alpha) COLOR_ID_YCbCrA
TYPE_YCbCr/CS_PYCC (w/ alpha) COLOR_ID_PYCCA
** Any Other ** COLOR_ID_UNKNOWN
</pre>
* When the user wants more control than the BufferedImage conversions
* provide, the user must encode the data from a Raster. In this case
* the data undergoes no color conversion at all. It is the user's
* responsiblity to perform the desired conversions.<P>
* If you intend to write a JFIF image (by including the APP0_MARKER)
* the encoded COLOR_ID must be one of: COLOR_ID_UNKNOWN,
* COLOR_ID_GRAYSCALE, COLOR_ID_YCbCr, or COLOR_ID_CMYK. In all other
* instances an ImageformatException will be thrown.<P>
* <B>IMPORTANT:</B> an Alpha RGB BufferedImage will not map to a
* valid JFIF stream, you must strip off the alpha prior to encoding
* if you want a JFIF file. If the APP0 marker is set and you do not
* strip off the Alpha, an ImageFormatException will be thrown.
* <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>
*/
public interface JPEGEncodeParam
extends Cloneable, JPEGDecodeParam
{
public Object clone();
/**
* Set the horizontal subsample factor for the given component.
* Note that the subsample factor is the number of input pixels
* that contribute to each output pixel (ussually 2 for YCC).
* @param component The component being specified.
* @param subsample The subsampling factor being specified.
*/
public void setHorizontalSubsampling(int component,
int subsample);
/**
* Set the vertical subsample factor for the given component. Note that
* the subsample factor is the number of input pixels that
* contribute to each output pixel (ussually 2 for YCC).
* @param component The component being specified.
* @param subsample The subsampling factor being specified.
*/
public void setVerticalSubsampling(int component,
int subsample);
/**
* Sets the coefficient quantization tables at index
* passed. tableNum must range in value from 0 - 3.
* @param qtable that will be used.
* @param tableNum the index of the table to be set.
*/
public void setQTable( int tableNum, JPEGQTable qTable );
/** Sets the DC Huffman coding table at index to the table provided.
* @param huffTable JPEGHuffmanTable that will be assigned
* to index tableNum.
* @param tableNum - the index of the table to be set.
* @exception IllegalArgumentException - thrown if the tableNum
* is out of range. Index must range in value from 0 - 3.
*/
public void setDCHuffmanTable( int tableNum,
JPEGHuffmanTable huffTable);
/** Sets the AC Huffman coding table at index to the table provided.
* @param huffTable JPEGHuffmanTable that will be assigned
* to index tableNum.
* @param tableNum - the index of the table to be set.
* @exception IllegalArgumentException - thrown if the tableNum
* is out of range. Index must range in value from 0 - 3.
*/
public void setACHuffmanTable( int tableNum,
JPEGHuffmanTable huffTable);
/**
* Sets the mapping between a component and it's DC Huffman Table.
* @param component The component to set the mapping for
* @param table The DC Huffman table to use for component
*/
public void setDCHuffmanComponentMapping( int component, int table);
/**
* Sets the mapping between a component and it's AC Huffman Table.
* @param component The component to set the mapping for
* @param table The AC Huffman table to use for component
*/
public void setACHuffmanComponentMapping( int component, int table);
/**
* Sets the mapping between a component and it's Quantization Table.
* @param component The component to set the mapping for
* @param table The Quantization Table to use for component
*/
public void setQTableComponentMapping( int component, int table);
/**
* Set the flag indicating the validity of the table information
* in the ParamBlock. This is used to indicate if tables should
* be included when encoding.
*/
public void setImageInfoValid(boolean flag);
/**
* Set the flag indicating the validity of the image information
* in the ParamBlock. This is used to indicates if image data
* should be written when encoding.
*/
public void setTableInfoValid(boolean flag);
/**
* Sets the marker data to be written to the output data stream.
* This removes any existing marker data in the JPEParm object.
* This can be used to remove the default APP0 marker by calling
* it with data set to null.
* @param marker The marker to set the data for.
* @param data the new set of data to be written.
*/
public void setMarkerData(int marker, byte[][] data);
/**
* Appends 'data' to the array of byte[] associated with
* marker. This will result in additional instance of the marker
* being written (one for each byte[] in the array.).
* @param marker The marker to add and instance of.
* @param data the data to be written.
*/
public void addMarkerData(int marker, byte []data);
/**
* Set the MCUs per restart, or 0 for no restart markers.
* @param restartInterval number MCUs per restart marker.
*/
public void setRestartInterval( int restartInterval );
/**
* Set the pixel size units This value is copied into the APP0
* marker (if that marker is written). This value isn't used by
* the JPEG code.
* @param unit One of the DENSITY_UNIT_* values.
*/
public void setDensityUnit( int unit);
/**
* Set the horizontal pixel density This value is written into the
* APP0 marker. It isn't used by the JPEG code.
* @param density the horizontal pixel density, in units
* described by @see JPEGParam.getDensityUnit.
*/
public void setXDensity( int density );
/**
* Set the vertical pixel density. This value is copied into
* the JFIF APP0 marker. It isn't used by the JPEG code.
* @param density The verticle pixel density, in units
* described by @see JPEGParam.getDensityUnit.
*/
public void setYDensity( int density );
/**
* This creates new Quantization tables that replace the currently
* installed Quantization tables. It also updates the Component
* QTable mapping to the default for the current encoded COLOR_ID.
* The Created Quantization table varies from very high
* compression, very low quality, (0.0) to low compression, very
* high quality (1.0) based on the quality parameter.<P>
* At a quality level of 1.0 the table will be all 1's which will
* lead to no loss of data due to quantization (however chrominace
* subsampling, if used, and roundoff error in the DCT will still
* degrade the image some what).<P>
* This is a linear manipulation of the standard Chrominance
* Q-Table.<P>
* <pre>Some guidelines: 0.75 high quality
* 0.5 medium quality
* 0.25 low quality
* </pre>
* @param quality 0.0-1.0 setting of desired quality level.
* @param forceBaseline force baseline quantization table
*/
public void setQuality(float quality, boolean forceBaseline );
}
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