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1
11 package org.eclipse.swt.internal.image;
12
13
14 final class JPEGQuantizationTable extends JPEGVariableSizeSegment {
15 public static byte[] DefaultLuminanceQTable = {
16 (byte)255, (byte)219, 0, 67, 0,
17 16, 11, 10, 16, 24, 40, 51, 61,
18 12, 12, 14, 19, 26, 58, 60, 55,
19 14, 13, 16, 24, 40, 57, 69, 56,
20 14, 17, 22, 29, 51, 87, 80, 62,
21 18, 22, 37, 56, 68, 109, 103, 77,
22 24, 35, 55, 64, 81, 104, 113, 92,
23 49, 64, 78, 87, 103, 121, 120, 101,
24 72, 92, 95, 98, 112, 100, 103, 99
25 };
26 public static byte[] DefaultChrominanceQTable = {
27 (byte)255, (byte)219, 0, 67, 1,
28 17, 18, 24, 47, 99, 99, 99, 99,
29 18, 21, 26, 66, 99, 99, 99, 99,
30 24, 26, 56, 99, 99, 99, 99, 99,
31 47, 66, 99, 99, 99, 99, 99, 99,
32 99, 99, 99, 99, 99, 99, 99, 99,
33 99, 99, 99, 99, 99, 99, 99, 99,
34 99, 99, 99, 99, 99, 99, 99, 99,
35 99, 99, 99, 99, 99, 99, 99, 99
36 };
37
38 public JPEGQuantizationTable(byte[] reference) {
39 super(reference);
40 }
41
42 public JPEGQuantizationTable(LEDataInputStream byteStream) {
43 super(byteStream);
44 }
45
46 public static JPEGQuantizationTable defaultChrominanceTable() {
47 byte[] data = new byte[DefaultChrominanceQTable.length];
48 System.arraycopy(DefaultChrominanceQTable, 0, data, 0, data.length);
49 return new JPEGQuantizationTable(data);
50 }
51
52 public static JPEGQuantizationTable defaultLuminanceTable() {
53 byte[] data = new byte[DefaultLuminanceQTable.length];
54 System.arraycopy(DefaultLuminanceQTable, 0, data, 0, data.length);
55 return new JPEGQuantizationTable(data);
56 }
57
58 public int[] getQuantizationTablesKeys() {
59 int[] keys = new int[4];
60 int keysIndex = 0;
61 int totalLength = getSegmentLength() - 2;
62 int ofs = 4;
63 while (totalLength > 64) {
64 int tq = reference[ofs] & 0xF;
65 int pq = (reference[ofs] & 0xFF) >> 4;
66 if (pq == 0) {
67 ofs += 65;
68 totalLength -= 65;
69 } else {
70 ofs += 129;
71 totalLength -= 129;
72 }
73 if (keysIndex >= keys.length) {
74 int[] newKeys = new int[keys.length + 4];
75 System.arraycopy(keys, 0, newKeys, 0, keys.length);
76 keys = newKeys;
77 }
78 keys[keysIndex] = tq;
79 keysIndex++;
80 }
81 int[] newKeys = new int[keysIndex];
82 System.arraycopy(keys, 0, newKeys, 0, keysIndex);
83 return newKeys;
84 }
85
86 public int[][] getQuantizationTablesValues() {
87 int[][] values = new int[4][];
88 int valuesIndex = 0;
89 int totalLength = getSegmentLength() - 2;
90 int ofs = 4;
91 while (totalLength > 64) {
92 int[] qk = new int[64];
93 int pq = (reference[ofs] & 0xFF) >> 4;
94 if (pq == 0) {
95 for (int i = 0; i < qk.length; i++) {
96 qk[i] = reference[ofs + i + 1] & 0xFF;
97 }
98 ofs += 65;
99 totalLength -= 65;
100 } else {
101 for (int i = 0; i < qk.length; i++) {
102 int idx = (i - 1) * 2 ;
103 qk[i] = (reference[ofs + idx + 1] & 0xFF) * 256 + (reference[ofs + idx + 2] & 0xFF);
104 }
105 ofs += 129;
106 totalLength -= 129;
107 }
108 if (valuesIndex >= values.length) {
109 int[][] newValues = new int[values.length + 4][];
110 System.arraycopy(values, 0, newValues, 0, values.length);
111 values = newValues;
112 }
113 values[valuesIndex] = qk;
114 valuesIndex++;
115 }
116 int[][] newValues = new int[valuesIndex][];
117 System.arraycopy(values, 0, newValues, 0, valuesIndex);
118 return newValues;
119 }
120
121 public void scaleBy(int qualityFactor) {
122 int qFactor = qualityFactor;
123 if (qFactor <= 0) {
124 qFactor = 1;
125 }
126 if (qFactor > 100) {
127 qFactor = 100;
128 }
129 if (qFactor < 50) {
130 qFactor = 5000 / qFactor;
131 } else {
132 qFactor = 200 - (qFactor * 2);
133 }
134 int totalLength = getSegmentLength() - 2;
135 int ofs = 4;
136 while (totalLength > 64) {
137 int pq = (reference[ofs] & 0xFF) >> 4;
139 if (pq == 0) {
140 for (int i = ofs + 1; i <= ofs + 64; i++) {
141 int temp = ((reference[i] & 0xFF) * qFactor + 50) / 100;
142 if (temp <= 0) temp = 1;
143 if (temp > 255) temp = 255;
144 reference[i] = (byte)temp;
145 }
146 ofs += 65;
147 totalLength -= 65;
148 } else {
149 for (int i = ofs + 1; i <= ofs + 128; i += 2) {
150 int temp = (((reference[i] & 0xFF) * 256 + (reference[i + 1] & 0xFF)) * qFactor + 50) / 100;
151 if (temp <= 0) temp = 1;
152 if (temp > 32767) temp = 32767;
153 reference[i] = (byte)(temp >> 8);
154 reference[i + 1] = (byte)(temp & 0xFF);
155 }
156 ofs += 129;
157 totalLength -= 129;
158 }
159 }
160 }
161
162 public int signature() {
163 return JPEGFileFormat.DQT;
164 }
165 }
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