001/*
002 * $RCSfile: DataBlk.java,v $
003 * $Revision: 1.1 $
004 * $Date: 2005/02/11 05:02:12 $
005 * $State: Exp $
006 *
007 * Interface:           DataBlk
008 *
009 * Description:         A generic interface to hold 2D blocks of data.
010 *
011 *
012 *
013 * COPYRIGHT:
014 *
015 * This software module was originally developed by Raphaël Grosbois and
016 * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
017 * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
018 * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
019 * Centre France S.A) in the course of development of the JPEG2000
020 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
021 * software module is an implementation of a part of the JPEG 2000
022 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
023 * Systems AB and Canon Research Centre France S.A (collectively JJ2000
024 * Partners) agree not to assert against ISO/IEC and users of the JPEG
025 * 2000 Standard (Users) any of their rights under the copyright, not
026 * including other intellectual property rights, for this software module
027 * with respect to the usage by ISO/IEC and Users of this software module
028 * or modifications thereof for use in hardware or software products
029 * claiming conformance to the JPEG 2000 Standard. Those intending to use
030 * this software module in hardware or software products are advised that
031 * their use may infringe existing patents. The original developers of
032 * this software module, JJ2000 Partners and ISO/IEC assume no liability
033 * for use of this software module or modifications thereof. No license
034 * or right to this software module is granted for non JPEG 2000 Standard
035 * conforming products. JJ2000 Partners have full right to use this
036 * software module for his/her own purpose, assign or donate this
037 * software module to any third party and to inhibit third parties from
038 * using this software module for non JPEG 2000 Standard conforming
039 * products. This copyright notice must be included in all copies or
040 * derivative works of this software module.
041 *
042 * Copyright (c) 1999/2000 JJ2000 Partners.
043 *
044 *
045 *
046 */
047
048package jj2000.j2k.image;
049
050/**
051 * This is a generic abstract class to store data from a block of an
052 * image. This class does not have the notion of components. Therefore, it
053 * should be used for data from a single component. Subclasses should
054 * implement the different types of storage (<tt>int</tt>,
055 * <tt>float</tt>, etc.).
056 *
057 * <P>The data is always stored in one array, of the type matching the data
058 * type (i.e. for 'int' it's an 'int[]'). The data should be stored in the
059 * array in standard scan-line order. That is the samples go from the top-left
060 * corner of the code-block to the lower-right corner by line and then column.
061 *
062 * <P>The member variable 'offset' gives the index in the array of the first
063 * data element (i.e. the top-left coefficient (ulx,uly)). The member variable
064 * 'scanw' gives the width of the scan that is used to store the data, that
065 * can be different from the width of the block. Element '(x,y)' of the
066 * code-block (i.e. '(ulx,uly)' is the top-left coefficient), will appear at
067 * position 'offset+(y-uly)*scanw+(x-ulx)' in the array of data.
068 *
069 * <P>A block of data can have the <i>progressive</i> attribute
070 * set. Data is progressive when it is obtained by successive
071 * refinement and the values in this block are approximations of the
072 * "final" values. When the final values are returned the progressive
073 * attribute must be turned off.
074 *
075 * <P>The classes <tt>DataBlkInt</tt> and <tt>DataBlkFloat</tt>
076 * provide implementations for <tt>int</tt> and <tt>float</tt> types
077 * respectively.
078 *
079 * @see DataBlkInt
080 *
081 * @see DataBlkFloat
082 * */
083public abstract class DataBlk {
084
085    /** The identifier for the <tt>byte</tt> data type, as signed 8
086        bits. */
087    public final static int TYPE_BYTE = 0;
088
089    /** The identifier for the <tt>short</tt> data type, as signed 16
090        bits. */
091    public final static int TYPE_SHORT = 1;
092
093    /** The identifier for the <tt>int</tt> data type, as signed 32
094        bits. */
095    public final static int TYPE_INT = 3;
096
097    /** The identifier for the <tt>float</tt> data type */
098    public final static int TYPE_FLOAT = 4;
099
100    /** The horizontal coordinate (in pixels) of the upper-left corner
101     *  of the block of data. This is relative to the component of the
102     *  image from where this block was filled or is to be filled.
103     */
104    public int ulx;
105
106    /** The vertical coordinate of the upper-left corner of the block
107     *  of data. This is relative to the component of the image from where
108     *  this block was filled or is to be filled.
109     */
110    public int uly;
111
112    /** The width of the block, in pixels. */
113    public int w;
114
115    /** The height of the block, in pixels. */
116    public int h;
117
118    /** The offset in the array of the top-left coefficient */
119    public int offset;
120
121    /** The width of the scanlines used to store the data in the array */
122    public int scanw;
123
124    /** The progressive attribute (<tt>false</tt> by default) */
125    public boolean progressive;
126
127    /**
128     * Returns the size in bits, given the data type. The data type
129     * must be one defined in this class. An
130     * <tt>IllegalArgumentException</tt> is thrown if <tt>type</tt> is
131     * not defined in this class.
132     *
133     * @param type The data type.
134     *
135     * @return The size in bits of the data type.
136     *
137     *
138     *
139     */
140    public static int getSize(int type) {
141        switch (type) {
142        case TYPE_BYTE:
143            return 8;
144        case TYPE_SHORT:
145            return 16;
146        case TYPE_INT:
147        case TYPE_FLOAT:
148            return 32;
149        default:
150            throw new IllegalArgumentException();
151        }
152    }
153
154    /**
155     * Returns the data type of the <tt>DataBlk</tt> object, as
156     * defined in this class.
157     *
158     * @return The data type of the object, as defined in thsi class.
159     *
160     *
161     *
162     */
163    public abstract int getDataType();
164
165    /**
166     * Returns the array containing the data, or null if there is no
167     * data. The returned array is of the type returned by
168     * <tt>getDataType()</tt> (e.g., for <tt>TYPE_INT</tt>, it is a
169     * <tt>int[]</tt>).
170     *
171     * <P>Each implementing class should provide a type specific
172     * equivalent method (e.g., <tt>getDataInt()</tt> in
173     * <tt>DataBlkInt</tt>) which returns an array of the correct
174     * type explicetely and not through an <tt>Object</tt>.
175     *
176     * @return The array containing the data, or <tt>null</tt> if
177     *         there is no data.
178     *
179     *
180     *
181     * @see #getDataType
182     *
183     */
184    public abstract Object getData();
185
186    /**
187     * Sets the data array to the specified one. The type of the
188     * specified data array must match the one returned by
189     * <tt>getDataType()</tt> (e.g., for <tt>TYPE_INT</tt>, it should
190     * be a <tt>int[]</tt>). If the wrong type of array is given a
191     * <tt>ClassCastException</tt> will be thrown.
192     *
193     * <P>The size of the array is not necessarily checked for
194     * consistency with <tt>w</tt> and <tt>h</tt> or any other fields.
195     *
196     * <P>Each implementing class should provide a type specific
197     * equivalent method (e.g., <tt>setDataInt()</tt> in
198     * <tt>DataBlkInt</tt>) which takes an array of the correct
199     * type explicetely and not through an <tt>Object</tt>.
200     *
201     * @param arr The new data array to use
202     *
203     *
204     *
205     * @see #getDataType
206     * */
207    public abstract void setData(Object arr);
208
209    /**
210     * Returns a string of informations about the DataBlk
211     *
212     * @return Block dimensions and progressiveness in a string
213     *
214     *
215     */
216    public String toString(){
217        String typeString = "";
218        switch(getDataType()){
219        case  TYPE_BYTE:
220            typeString = "Unsigned Byte";
221            break;
222        case  TYPE_SHORT:
223            typeString = "Short";
224            break;
225        case  TYPE_INT:
226            typeString = "Integer";
227            break;
228        case  TYPE_FLOAT:
229            typeString = "Float";
230            break;
231        }
232
233        return
234            "DataBlk: "+
235            "upper-left("+ulx+","+uly+"), width= "+w+
236            ", height= "+h+", progressive= "+progressive+
237            ", offset= "+offset+", scanw= "+scanw+
238            ", type= "+typeString;
239    }
240}