1 /*
2 * Copyright (c) 1997, 2000, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.awt.image;
27
28
29 /**
30 * This class defines a lookup table object. The output of a
31 * lookup operation using an object of this class is interpreted
32 * as an unsigned short quantity. The lookup table contains short
33 * data arrays for one or more bands (or components) of an image,
34 * and it contains an offset which will be subtracted from the
35 * input values before indexing the arrays. This allows an array
36 * smaller than the native data size to be provided for a
37 * constrained input. If there is only one array in the lookup
38 * table, it will be applied to all bands.
39 *
40 * @see ByteLookupTable
41 * @see LookupOp
42 */
43 public class ShortLookupTable extends LookupTable {
44
45 /**
46 * Constants
47 */
48
49 short data[][];
50
51 /**
52 * Constructs a ShortLookupTable object from an array of short
53 * arrays representing a lookup table for each
54 * band. The offset will be subtracted from the input
55 * values before indexing into the arrays. The number of
56 * bands is the length of the data argument. The
57 * data array for each band is stored as a reference.
58 * @param offset the value subtracted from the input values
59 * before indexing into the arrays
60 * @param data an array of short arrays representing a lookup
61 * table for each band
62 */
63 public ShortLookupTable(int offset, short data[][]) {
64 super(offset,data.length);
65 numComponents = data.length;
66 numEntries = data[0].length;
67 this.data = new short[numComponents][];
68 // Allocate the array and copy the data reference
69 for (int i=0; i < numComponents; i++) {
70 this.data[i] = data[i];
71 }
72 }
73
74 /**
75 * Constructs a ShortLookupTable object from an array
76 * of shorts representing a lookup table for each
77 * band. The offset will be subtracted from the input
78 * values before indexing into the array. The
79 * data array is stored as a reference.
80 * @param offset the value subtracted from the input values
81 * before indexing into the arrays
82 * @param data an array of shorts
83 */
84 public ShortLookupTable(int offset, short data[]) {
85 super(offset,data.length);
86 numComponents = 1;
87 numEntries = data.length;
88 this.data = new short[1][];
89 this.data[0] = data;
90 }
91
92 /**
93 * Returns the lookup table data by reference. If this ShortLookupTable
94 * was constructed using a single short array, the length of the returned
95 * array is one.
96 * @return ShortLookupTable data array.
97 */
98 public final short[][] getTable(){
99 return data;
100 }
101
102 /**
103 * Returns an array of samples of a pixel, translated with the lookup
104 * table. The source and destination array can be the same array.
105 * Array <code>dst</code> is returned.
106 *
107 * @param src the source array.
108 * @param dst the destination array. This array must be at least as
109 * long as <code>src</code>. If <code>dst</code> is
110 * <code>null</code>, a new array will be allocated having the
111 * same length as <code>src</code>.
112 * @return the array <code>dst</code>, an <code>int</code> array of
113 * samples.
114 * @exception ArrayIndexOutOfBoundsException if <code>src</code> is
115 * longer than <code>dst</code> or if for any element
116 * <code>i</code> of <code>src</code>,
117 * <code>(src[i]&0xffff)-offset</code> is either less than
118 * zero or greater than or equal to the length of the
119 * lookup table for any band.
120 */
121 public int[] lookupPixel(int[] src, int[] dst){
122 if (dst == null) {
123 // Need to alloc a new destination array
124 dst = new int[src.length];
125 }
126
127 if (numComponents == 1) {
128 // Apply one LUT to all channels
129 for (int i=0; i < src.length; i++) {
130 int s = (src[i]&0xffff) - offset;
131 if (s < 0) {
132 throw new ArrayIndexOutOfBoundsException("src["+i+
133 "]-offset is "+
134 "less than zero");
135 }
136 dst[i] = (int) data[0][s];
137 }
138 }
139 else {
140 for (int i=0; i < src.length; i++) {
141 int s = (src[i]&0xffff) - offset;
142 if (s < 0) {
143 throw new ArrayIndexOutOfBoundsException("src["+i+
144 "]-offset is "+
145 "less than zero");
146 }
147 dst[i] = (int) data[i][s];
148 }
149 }
150 return dst;
151 }
152
153 /**
154 * Returns an array of samples of a pixel, translated with the lookup
155 * table. The source and destination array can be the same array.
156 * Array <code>dst</code> is returned.
157 *
158 * @param src the source array.
159 * @param dst the destination array. This array must be at least as
160 * long as <code>src</code>. If <code>dst</code> is
161 * <code>null</code>, a new array will be allocated having the
162 * same length as <code>src</code>.
163 * @return the array <code>dst</code>, an <code>int</code> array of
164 * samples.
165 * @exception ArrayIndexOutOfBoundsException if <code>src</code> is
166 * longer than <code>dst</code> or if for any element
167 * <code>i</code> of <code>src</code>,
168 * <code>(src[i]&0xffff)-offset</code> is either less than
169 * zero or greater than or equal to the length of the
170 * lookup table for any band.
171 */
172 public short[] lookupPixel(short[] src, short[] dst){
173 if (dst == null) {
174 // Need to alloc a new destination array
175 dst = new short[src.length];
176 }
177
178 if (numComponents == 1) {
179 // Apply one LUT to all channels
180 for (int i=0; i < src.length; i++) {
181 int s = (src[i]&0xffff) - offset;
182 if (s < 0) {
183 throw new ArrayIndexOutOfBoundsException("src["+i+
184 "]-offset is "+
185 "less than zero");
186 }
187 dst[i] = data[0][s];
188 }
189 }
190 else {
191 for (int i=0; i < src.length; i++) {
192 int s = (src[i]&0xffff) - offset;
193 if (s < 0) {
194 throw new ArrayIndexOutOfBoundsException("src["+i+
195 "]-offset is "+
196 "less than zero");
197 }
198 dst[i] = data[i][s];
199 }
200 }
201 return dst;
202 }
203
204 }