/*
* 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.
*/
using System;
using BarcodeFormat = com.google.zxing.BarcodeFormat;
using ReaderException = com.google.zxing.ReaderException;
using Result = com.google.zxing.Result;
using ResultPoint = com.google.zxing.ResultPoint;
using BitArray = com.google.zxing.common.BitArray;
namespace com.google.zxing.oned
{
/// <summary> <p>Decodes Code 39 barcodes. This does not support "Full ASCII Code 39" yet.</p>
///
/// </summary>
/// <author> Sean Owen
/// </author>
/// <author>www.Redivivus.in (suraj.supekar@redivivus.in) - Ported from ZXING Java Source
/// </author>
public sealed class Code39Reader:OneDReader
{
private const System.String ALPHABET_STRING = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. *$/+%";
//UPGRADE_NOTE: Final was removed from the declaration of 'ALPHABET '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly char[] ALPHABET = ALPHABET_STRING.ToCharArray();
/// <summary> These represent the encodings of characters, as patterns of wide and narrow bars.
/// The 9 least-significant bits of each int correspond to the pattern of wide and narrow,
/// with 1s representing "wide" and 0s representing narrow.
/// </summary>
//UPGRADE_NOTE: Final was removed from the declaration of 'CHARACTER_ENCODINGS'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly int[] CHARACTER_ENCODINGS = new int[]{0x034, 0x121, 0x061, 0x160, 0x031, 0x130, 0x070, 0x025, 0x124, 0x064, 0x109, 0x049, 0x148, 0x019, 0x118, 0x058, 0x00D, 0x10C, 0x04C, 0x01C, 0x103, 0x043, 0x142, 0x013, 0x112, 0x052, 0x007, 0x106, 0x046, 0x016, 0x181, 0x0C1, 0x1C0, 0x091, 0x190, 0x0D0, 0x085, 0x184, 0x0C4, 0x094, 0x0A8, 0x0A2, 0x08A, 0x02A};
//UPGRADE_NOTE: Final was removed from the declaration of 'ASTERISK_ENCODING '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly int ASTERISK_ENCODING = CHARACTER_ENCODINGS[39];
//UPGRADE_NOTE: Final was removed from the declaration of 'usingCheckDigit '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private bool usingCheckDigit;
//UPGRADE_NOTE: Final was removed from the declaration of 'extendedMode '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private bool extendedMode;
/// <summary> Creates a reader that assumes all encoded data is data, and does not treat the final
/// character as a check digit. It will not decoded "extended Code 39" sequences.
/// </summary>
public Code39Reader()
{
usingCheckDigit = false;
extendedMode = false;
}
/// <summary> Creates a reader that can be configured to check the last character as a check digit.
/// It will not decoded "extended Code 39" sequences.
///
/// </summary>
/// <param name="usingCheckDigit">if true, treat the last data character as a check digit, not
/// data, and verify that the checksum passes.
/// </param>
public Code39Reader(bool usingCheckDigit)
{
this.usingCheckDigit = usingCheckDigit;
this.extendedMode = false;
}
/// <summary> Creates a reader that can be configured to check the last character as a check digit,
/// or optionally attempt to decode "extended Code 39" sequences that are used to encode
/// the full ASCII character set.
///
/// </summary>
/// <param name="usingCheckDigit">if true, treat the last data character as a check digit, not
/// data, and verify that the checksum passes.
/// </param>
/// <param name="extendedMode">if true, will attempt to decode extended Code 39 sequences in the
/// text.
/// </param>
public Code39Reader(bool usingCheckDigit, bool extendedMode)
{
this.usingCheckDigit = usingCheckDigit;
this.extendedMode = extendedMode;
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
int[] start = findAsteriskPattern(row);
int nextStart = start[1];
int end = row.Size;
// Read off white space
while (nextStart < end && !row.get_Renamed(nextStart))
{
nextStart++;
}
System.Text.StringBuilder result = new System.Text.StringBuilder(20);
int[] counters = new int[9];
char decodedChar;
int lastStart;
do
{
recordPattern(row, nextStart, counters);
int pattern = toNarrowWidePattern(counters);
if (pattern < 0)
{
throw ReaderException.Instance;
}
decodedChar = patternToChar(pattern);
result.Append(decodedChar);
lastStart = nextStart;
for (int i = 0; i < counters.Length; i++)
{
nextStart += counters[i];
}
// Read off white space
while (nextStart < end && !row.get_Renamed(nextStart))
{
nextStart++;
}
}
while (decodedChar != '*');
result.Remove(result.Length - 1, 1); // remove asterisk
// Look for whitespace after pattern:
int lastPatternSize = 0;
for (int i = 0; i < counters.Length; i++)
{
lastPatternSize += counters[i];
}
int whiteSpaceAfterEnd = nextStart - lastStart - lastPatternSize;
// If 50% of last pattern size, following last pattern, is not whitespace, fail
// (but if it's whitespace to the very end of the image, that's OK)
if (nextStart != end && whiteSpaceAfterEnd / 2 < lastPatternSize)
{
throw ReaderException.Instance;
}
if (usingCheckDigit)
{
int max = result.Length - 1;
int total = 0;
for (int i = 0; i < max; i++)
{
total += ALPHABET_STRING.IndexOf((System.Char) result[i]);
}
if (total % 43 != ALPHABET_STRING.IndexOf((System.Char) result[max]))
{
throw ReaderException.Instance;
}
result.Remove(max, 1);
}
System.String resultString = result.ToString();
if (extendedMode)
{
resultString = decodeExtended(resultString);
}
if (resultString.Length == 0)
{
// Almost surely a false positive
throw ReaderException.Instance;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float left = (float) (start[1] + start[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float right = (float) (nextStart + lastStart) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return new Result(resultString, null, new ResultPoint[]{new ResultPoint(left, (float) rowNumber), new ResultPoint(right, (float) rowNumber)}, BarcodeFormat.CODE_39);
}
private static int[] findAsteriskPattern(BitArray row)
{
int width = row.Size;
int rowOffset = 0;
while (rowOffset < width)
{
if (row.get_Renamed(rowOffset))
{
break;
}
rowOffset++;
}
int counterPosition = 0;
int[] counters = new int[9];
int patternStart = rowOffset;
bool isWhite = false;
int patternLength = counters.Length;
for (int i = rowOffset; i < width; i++)
{
bool pixel = row.get_Renamed(i);
if (pixel ^ isWhite)
{
counters[counterPosition]++;
}
else
{
if (counterPosition == patternLength - 1)
{
if (toNarrowWidePattern(counters) == ASTERISK_ENCODING)
{
// Look for whitespace before start pattern, >= 50% of width of start pattern
if (row.isRange(System.Math.Max(0, patternStart - (i - patternStart) / 2), patternStart, false))
{
return new int[]{patternStart, i};
}
}
patternStart += counters[0] + counters[1];
for (int y = 2; y < patternLength; y++)
{
counters[y - 2] = counters[y];
}
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
}
else
{
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw ReaderException.Instance;
}
// For efficiency, returns -1 on failure. Not throwing here saved as many as 700 exceptions
// per image when using some of our blackbox images.
private static int toNarrowWidePattern(int[] counters)
{
int numCounters = counters.Length;
int maxNarrowCounter = 0;
int wideCounters;
do
{
int minCounter = System.Int32.MaxValue;
for (int i = 0; i < numCounters; i++)
{
int counter = counters[i];
if (counter < minCounter && counter > maxNarrowCounter)
{
minCounter = counter;
}
}
maxNarrowCounter = minCounter;
wideCounters = 0;
int totalWideCountersWidth = 0;
int pattern = 0;
for (int i = 0; i < numCounters; i++)
{
int counter = counters[i];
if (counters[i] > maxNarrowCounter)
{
pattern |= 1 << (numCounters - 1 - i);
wideCounters++;
totalWideCountersWidth += counter;
}
}
if (wideCounters == 3)
{
// Found 3 wide counters, but are they close enough in width?
// We can perform a cheap, conservative check to see if any individual
// counter is more than 1.5 times the average:
for (int i = 0; i < numCounters && wideCounters > 0; i++)
{
int counter = counters[i];
if (counters[i] > maxNarrowCounter)
{
wideCounters--;
// totalWideCountersWidth = 3 * average, so this checks if counter >= 3/2 * average
if ((counter << 1) >= totalWideCountersWidth)
{
return - 1;
}
}
}
return pattern;
}
}
while (wideCounters > 3);
return - 1;
}
private static char patternToChar(int pattern)
{
for (int i = 0; i < CHARACTER_ENCODINGS.Length; i++)
{
if (CHARACTER_ENCODINGS[i] == pattern)
{
return ALPHABET[i];
}
}
throw ReaderException.Instance;
}
private static System.String decodeExtended(System.String encoded)
{
int length = encoded.Length;
System.Text.StringBuilder decoded = new System.Text.StringBuilder(length);
for (int i = 0; i < length; i++)
{
char c = encoded[i];
if (c == '+' || c == '$' || c == '%' || c == '/')
{
char next = encoded[i + 1];
char decodedChar = '\x0000';
switch (c)
{
case '+':
// +A to +Z map to a to z
if (next >= 'A' && next <= 'Z')
{
decodedChar = (char) (next + 32);
}
else
{
throw ReaderException.Instance;
}
break;
case '$':
// $A to $Z map to control codes SH to SB
if (next >= 'A' && next <= 'Z')
{
decodedChar = (char) (next - 64);
}
else
{
throw ReaderException.Instance;
}
break;
case '%':
// %A to %E map to control codes ESC to US
if (next >= 'A' && next <= 'E')
{
decodedChar = (char) (next - 38);
}
else if (next >= 'F' && next <= 'W')
{
decodedChar = (char) (next - 11);
}
else
{
throw ReaderException.Instance;
}
break;
case '/':
// /A to /O map to ! to , and /Z maps to :
if (next >= 'A' && next <= 'O')
{
decodedChar = (char) (next - 32);
}
else if (next == 'Z')
{
decodedChar = ':';
}
else
{
throw ReaderException.Instance;
}
break;
}
decoded.Append(decodedChar);
// bump up i again since we read two characters
i++;
}
else
{
decoded.Append(c);
}
}
return decoded.ToString();
}
}
}