2 * Copyright 2008 ZXing authors
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package com.google.zxing.common.reedsolomon;
19 import java.util.Random;
22 * @author srowen@google.com (Sean Owen)
24 public final class ReedSolomonDecoderQRCodeTestCase extends AbstractReedSolomonTestCase {
26 /** See ISO 18004, Appendix I, from which this example is taken. */
27 private static final int[] QR_CODE_TEST =
28 { 0x10, 0x20, 0x0C, 0x56, 0x61, 0x80, 0xEC, 0x11, 0xEC,
29 0x11, 0xEC, 0x11, 0xEC, 0x11, 0xEC, 0x11, 0xA5 };
30 private static final int[] QR_CODE_TEST_WITH_EC =
31 { 0x10, 0x20, 0x0C, 0x56, 0x61, 0x80, 0xEC, 0x11, 0xEC,
32 0x11, 0xEC, 0x11, 0xEC, 0x11, 0xEC, 0x11, 0xA5, 0x24,
33 0xD4, 0xC1, 0xED, 0x36, 0xC7, 0x87, 0x2C, 0x55 };
34 private static final int QR_CODE_CORRECTABLE = (QR_CODE_TEST_WITH_EC.length - QR_CODE_TEST.length) / 2;
36 private final ReedSolomonDecoder qrRSDecoder = new ReedSolomonDecoder(GF256.QR_CODE_FIELD);
38 public void testNoError() throws ReedSolomonException {
39 int[] received = new int[QR_CODE_TEST_WITH_EC.length];
40 System.arraycopy(QR_CODE_TEST_WITH_EC, 0, received, 0, received.length);
42 checkQRRSDecode(received);
45 public void testOneError() throws ReedSolomonException {
46 int[] received = new int[QR_CODE_TEST_WITH_EC.length];
47 Random random = new Random(0xDEADBEEFL);
48 for (int i = 0; i < received.length; i++) {
49 System.arraycopy(QR_CODE_TEST_WITH_EC, 0, received, 0, received.length);
50 received[i] = random.nextInt(256);
51 checkQRRSDecode(received);
55 public void testMaxErrors() throws ReedSolomonException {
56 int[] received = new int[QR_CODE_TEST_WITH_EC.length];
57 Random random = new Random(0xDEADBEEFL);
58 for (int i = 0; i < QR_CODE_TEST.length; i++) { // # iterations is kind of arbitrary
59 System.arraycopy(QR_CODE_TEST_WITH_EC, 0, received, 0, received.length);
60 corrupt(received, QR_CODE_CORRECTABLE, random);
61 checkQRRSDecode(received);
65 public void testTooManyErrors() {
66 int[] received = new int[QR_CODE_TEST_WITH_EC.length];
67 System.arraycopy(QR_CODE_TEST_WITH_EC, 0, received, 0, received.length);
68 Random random = new Random(0xDEADBEEFL);
69 corrupt(received, QR_CODE_CORRECTABLE + 1, random);
71 checkQRRSDecode(received);
72 fail("Should not have decoded");
73 } catch (ReedSolomonException rse) {
78 private void checkQRRSDecode(int[] received) throws ReedSolomonException {
79 qrRSDecoder.decode(received, 2*QR_CODE_CORRECTABLE);
80 for (int i = 0; i < QR_CODE_TEST.length; i++) {
81 assertEquals(received[i], QR_CODE_TEST[i]);