From c9ead4ce8a61465dce70f4a763df04f381da2822 Mon Sep 17 00:00:00 2001 From: srowen Date: Fri, 20 Jun 2008 22:38:35 +0000 Subject: [PATCH] Added some degree of support for Character Set ECIs git-svn-id: https://zxing.googlecode.com/svn/trunk@467 59b500cc-1b3d-0410-9834-0bbf25fbcc57 --- .../zxing/qrcode/decoder/CharacterSetECI.java | 73 +++++++++++++++++++ .../decoder/DecodedBitStreamParser.java | 41 ++++------- .../com/google/zxing/qrcode/decoder/ECI.java | 65 +++++++++++++++++ .../zxing/qrcode/decoder/ECITestCase.java | 42 +++++++++++ 4 files changed, 196 insertions(+), 25 deletions(-) create mode 100644 core/src/com/google/zxing/qrcode/decoder/CharacterSetECI.java create mode 100644 core/src/com/google/zxing/qrcode/decoder/ECI.java create mode 100644 core/test/src/com/google/zxing/qrcode/decoder/ECITestCase.java diff --git a/core/src/com/google/zxing/qrcode/decoder/CharacterSetECI.java b/core/src/com/google/zxing/qrcode/decoder/CharacterSetECI.java new file mode 100644 index 000000000..674e99236 --- /dev/null +++ b/core/src/com/google/zxing/qrcode/decoder/CharacterSetECI.java @@ -0,0 +1,73 @@ +/* + * Copyright 2008 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.qrcode.decoder; + +import java.util.Hashtable; + +/** + * Encapsulates a Character Set ECI, according to "Extended Channel Interpretations" 5.3.1.1. + * + * @author srowen@google.com (Sean Owen) + */ +final class CharacterSetECI extends ECI { + + private static final Hashtable VALUE_TO_ECI; + static { + VALUE_TO_ECI = new Hashtable(29); + // TODO figure out if these values are even right! + addCharacterSet(3, "ISO8859_1"); + addCharacterSet(4, "ISO8859_2"); + addCharacterSet(5, "ISO8859_3"); + addCharacterSet(6, "ISO8859_4"); + addCharacterSet(7, "ISO8859_5"); + addCharacterSet(8, "ISO8859_6"); + addCharacterSet(9, "ISO8859_7"); + addCharacterSet(10, "ISO8859_8"); + addCharacterSet(11, "ISO8859_9"); + addCharacterSet(12, "ISO8859_10"); + addCharacterSet(13, "ISO8859_11"); + addCharacterSet(15, "ISO8859_13"); + addCharacterSet(16, "ISO8859_14"); + addCharacterSet(17, "ISO8859_15"); + addCharacterSet(18, "ISO8859_16"); + addCharacterSet(20, "Shift_JIS"); + } + + private final String encodingName; + + private CharacterSetECI(int value, String encodingName) { + super(value); + this.encodingName = encodingName; + } + + String getEncodingName() { + return encodingName; + } + + private static void addCharacterSet(int value, String encodingName) { + VALUE_TO_ECI.put(new Integer(value), new CharacterSetECI(value, encodingName)); + } + + static CharacterSetECI getCharacterSetECIByValue(int value) { + CharacterSetECI eci = (CharacterSetECI) VALUE_TO_ECI.get(new Integer(value)); + if (eci == null) { + throw new IllegalArgumentException("Unsupported value: " + value); + } + return eci; + } + +} \ No newline at end of file diff --git a/core/src/com/google/zxing/qrcode/decoder/DecodedBitStreamParser.java b/core/src/com/google/zxing/qrcode/decoder/DecodedBitStreamParser.java index a74ba4de3..334370577 100644 --- a/core/src/com/google/zxing/qrcode/decoder/DecodedBitStreamParser.java +++ b/core/src/com/google/zxing/qrcode/decoder/DecodedBitStreamParser.java @@ -57,6 +57,7 @@ final class DecodedBitStreamParser { static String decode(byte[] bytes, Version version) throws ReaderException { BitSource bits = new BitSource(bytes); StringBuffer result = new StringBuffer(); + CharacterSetECI currentCharacterSetECI = null; Mode mode; do { // While still another segment to read... @@ -69,11 +70,12 @@ final class DecodedBitStreamParser { if (!mode.equals(Mode.TERMINATOR)) { if (mode.equals(Mode.ECI)) { // Count doesn't apply to ECI - parseECI(bits); - // We don't currently do anything with ECI, since there seems to be no reference - // defining what each value means. AIM's "Extended Channel Interpretations" does - // not define it. I have never observed a QR Code using it. So for now, we at least - // parse it but don't know how to take action on it. + int value = ECI.parseECI(bits); + try { + currentCharacterSetECI = CharacterSetECI.getCharacterSetECIByValue(value); + } catch (IllegalArgumentException iae) { + // unsupported... just continue? + } } else { // How many characters will follow, encoded in this mode? int count = bits.readBits(mode.getCharacterCountBits(version)); @@ -82,7 +84,7 @@ final class DecodedBitStreamParser { } else if (mode.equals(Mode.ALPHANUMERIC)) { decodeAlphanumericSegment(bits, result, count); } else if (mode.equals(Mode.BYTE)) { - decodeByteSegment(bits, result, count); + decodeByteSegment(bits, result, count, currentCharacterSetECI); } else if (mode.equals(Mode.KANJI)) { decodeKanjiSegment(bits, result, count); } else { @@ -104,23 +106,6 @@ final class DecodedBitStreamParser { return result.toString(); } - private static int parseECI(BitSource bits) { - int firstByte = bits.readBits(8); - if ((firstByte & 0x80) == 0) { - // just one byte - return firstByte & 0x7F; - } else if ((firstByte & 0xC0) == 0x80) { - // two bytes - int secondByte = bits.readBits(8); - return ((firstByte & 0x3F) << 8) | secondByte; - } else if ((firstByte & 0xE0) == 0xC0) { - // three bytes - int secondThirdBytes = bits.readBits(16); - return ((firstByte & 0x1F) << 16) | secondThirdBytes; - } - throw new IllegalArgumentException("Bad ECI bits starting with byte " + firstByte); - } - private static void decodeKanjiSegment(BitSource bits, StringBuffer result, int count) throws ReaderException { @@ -154,7 +139,8 @@ final class DecodedBitStreamParser { private static void decodeByteSegment(BitSource bits, StringBuffer result, - int count) throws ReaderException { + int count, + CharacterSetECI currentCharacterSetECI) throws ReaderException { byte[] readBytes = new byte[count]; if (count << 3 > bits.available()) { throw new ReaderException("Count too large: " + count); @@ -162,12 +148,17 @@ final class DecodedBitStreamParser { for (int i = 0; i < count; i++) { readBytes[i] = (byte) bits.readBits(8); } + String encoding; + if (currentCharacterSetECI == null) { // The spec isn't clear on this mode; see // section 6.4.5: t does not say which encoding to assuming // upon decoding. I have seen ISO-8859-1 used as well as // Shift_JIS -- without anything like an ECI designator to // give a hint. - String encoding = guessEncoding(readBytes); + encoding = guessEncoding(readBytes); + } else { + encoding = currentCharacterSetECI.getEncodingName(); + } try { result.append(new String(readBytes, encoding)); } catch (UnsupportedEncodingException uce) { diff --git a/core/src/com/google/zxing/qrcode/decoder/ECI.java b/core/src/com/google/zxing/qrcode/decoder/ECI.java new file mode 100644 index 000000000..96a1aeed3 --- /dev/null +++ b/core/src/com/google/zxing/qrcode/decoder/ECI.java @@ -0,0 +1,65 @@ +/* + * Copyright 2008 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.qrcode.decoder; + +import com.google.zxing.common.BitSource; + +/** + * Superclass of classes encapsulating types ECIs, according to "Extended Channel Interpretations" 5.3. + * + * @author srowen@google.com (Sean Owen) + */ +abstract class ECI { + + private final int value; + + ECI(int value) { + this.value = value; + } + + int getValue() { + return value; + } + + static ECI getECIByValue(int value) { + if (value < 0 || value > 999999) { + throw new IllegalArgumentException("Bad ECI value: " + value); + } + if (value < 900) { // Character set ECIs use 000000 - 000899 + return CharacterSetECI.getCharacterSetECIByValue(value); + } + throw new IllegalArgumentException("Unsupported ECI value: " + value); + } + + static int parseECI(BitSource bits) { + int firstByte = bits.readBits(8); + if ((firstByte & 0x80) == 0) { + // just one byte + return firstByte & 0x7F; + } else if ((firstByte & 0xC0) == 0x80) { + // two bytes + int secondByte = bits.readBits(8); + return ((firstByte & 0x3F) << 8) | secondByte; + } else if ((firstByte & 0xE0) == 0xC0) { + // three bytes + int secondThirdBytes = bits.readBits(16); + return ((firstByte & 0x1F) << 16) | secondThirdBytes; + } + throw new IllegalArgumentException("Bad ECI bits starting with byte " + firstByte); + } + +} diff --git a/core/test/src/com/google/zxing/qrcode/decoder/ECITestCase.java b/core/test/src/com/google/zxing/qrcode/decoder/ECITestCase.java new file mode 100644 index 000000000..dc9c5e895 --- /dev/null +++ b/core/test/src/com/google/zxing/qrcode/decoder/ECITestCase.java @@ -0,0 +1,42 @@ +/* + * Copyright 2008 ZXing authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.zxing.qrcode.decoder; + +import com.google.zxing.common.BitSource; +import junit.framework.TestCase; + +/** + * @author srowen@google.com (Sean Owen) + */ +public final class ECITestCase extends TestCase { + + public void testParseECI() { + doTestParseECI(0, new byte[] { (byte) 0x00 }); + doTestParseECI(127, new byte[] { (byte) 0x7F }); + doTestParseECI(128, new byte[] { (byte) 0x80, (byte) 0x80 }); + doTestParseECI(16383, new byte[] { (byte) 0xBF, (byte) 0xFF }); + doTestParseECI(16384, new byte[] { (byte) 0xC0, (byte) 0x40, (byte) 0x00 }); + doTestParseECI(2097151, new byte[] { (byte) 0xDF, (byte) 0xFF, (byte) 0xFF }); + } + + private static void doTestParseECI(int expectedValue, byte[] bytes) { + BitSource bitSource = new BitSource(bytes); + int actual = ECI.parseECI(bitSource); + assertEquals(expectedValue, actual); + } + +} \ No newline at end of file