text: //---------------------------------------------------------------------
  //
  // QR Code Generator for JavaScript
  //
  // Copyright (c) 2009 Kazuhiko Arase
  //
  // URL: http://www.d-project.com/
  //
  // Licensed under the MIT license:
  //	http://www.opensource.org/licenses/mit-license.php
  //
  // The word 'QR Code' is registered trademark of
  // DENSO WAVE INCORPORATED
  //	http://www.denso-wave.com/qrcode/faqpatent-e.html
  //
  //---------------------------------------------------------------------
  
  //---------------微信小程序基于base64生成二维码插件修改-------------------
  /*
   * @Modified: Pudon
   * @demoURL: https://github.com/Pudon/weapp-qrcode
   * @Date: 2018-09-11 14:00:05 
   * @Last Modified by: Pudon
   * @Last Modified time: 2018-09-12 16:33:19
   */
  //---------------------------------------------------------------------
  
  /**
   * qrcode
   * @param typeNumber 1 to 40
   * @param errorCorrectLevel 'L','M','Q','H'
   */
  var qrcode = function(typeNumber, errorCorrectLevel) {
  
      var PAD0 = 0xEC;
      var PAD1 = 0x11;
  
      var _typeNumber = typeNumber;
      var _errorCorrectLevel = QRErrorCorrectLevel[errorCorrectLevel];
      var _modules = null;
      var _moduleCount = 0;
      var _dataCache = null;
      var _dataList = new Array();
  
      var _this = {};
  
      var makeImpl = function(test, maskPattern) {
  
  	_moduleCount = _typeNumber * 4 + 17;
  	_modules = function(moduleCount) {
  	    var modules = new Array(moduleCount);
  	    for (var row = 0; row < moduleCount; row += 1) {
  		modules[row] = new Array(moduleCount);
  		for (var col = 0; col < moduleCount; col += 1) {
  		    modules[row][col] = null;
  		}
  	    }
  	    return modules;
  	}(_moduleCount);
  
  	setupPositionProbePattern(0, 0);
  	setupPositionProbePattern(_moduleCount - 7, 0);
  	setupPositionProbePattern(0, _moduleCount - 7);
  	setupPositionAdjustPattern();
  	setupTimingPattern();
  	setupTypeInfo(test, maskPattern);
  
  	if (_typeNumber >= 7) {
  	    setupTypeNumber(test);
  	}
  
  	if (_dataCache == null) {
  	    _dataCache = createData(_typeNumber, _errorCorrectLevel, _dataList);
  	}
  
  	mapData(_dataCache, maskPattern);
      };
  
      var setupPositionProbePattern = function(row, col) {
  
  	for (var r = -1; r <= 7; r += 1) {
  
  	    if (row + r <= -1 || _moduleCount <= row + r) continue;
  
  	    for (var c = -1; c <= 7; c += 1) {
  
  		if (col + c <= -1 || _moduleCount <= col + c) continue;
  
  		if ( (0 <= r && r <= 6 && (c == 0 || c == 6) )
  		     || (0 <= c && c <= 6 && (r == 0 || r == 6) )
  		     || (2 <= r && r <= 4 && 2 <= c && c <= 4) ) {
  		    _modules[row + r][col + c] = true;
  		} else {
  		    _modules[row + r][col + c] = false;
  		}
  	    }
  	}
      };
  
      var getBestMaskPattern = function() {
  
  	var minLostPoint = 0;
  	var pattern = 0;
  
  	for (var i = 0; i < 8; i += 1) {
  
  	    makeImpl(true, i);
  
  	    var lostPoint = QRUtil.getLostPoint(_this);
  
  	    if (i == 0 || minLostPoint > lostPoint) {
  		minLostPoint = lostPoint;
  		pattern = i;
  	    }
  	}
  
  	return pattern;
      };
  
      var setupTimingPattern = function() {
  
  	for (var r = 8; r < _moduleCount - 8; r += 1) {
  	    if (_modules[r][6] != null) {
  		continue;
  	    }
  	    _modules[r][6] = (r % 2 == 0);
  	}
  
  	for (var c = 8; c < _moduleCount - 8; c += 1) {
  	    if (_modules[6][c] != null) {
  		continue;
  	    }
  	    _modules[6][c] = (c % 2 == 0);
  	}
      };
  
      var setupPositionAdjustPattern = function() {
  
  	var pos = QRUtil.getPatternPosition(_typeNumber);
  
  	for (var i = 0; i < pos.length; i += 1) {
  
  	    for (var j = 0; j < pos.length; j += 1) {
  
  		var row = pos[i];
  		var col = pos[j];
  
  		if (_modules[row][col] != null) {
  		    continue;
  		}
  
  		for (var r = -2; r <= 2; r += 1) {
  
  		    for (var c = -2; c <= 2; c += 1) {
  
  			if (r == -2 || r == 2 || c == -2 || c == 2
  			    || (r == 0 && c == 0) ) {
  			    _modules[row + r][col + c] = true;
  			} else {
  			    _modules[row + r][col + c] = false;
  			}
  		    }
  		}
  	    }
  	}
      };
  
      var setupTypeNumber = function(test) {
  
  	var bits = QRUtil.getBCHTypeNumber(_typeNumber);
  
  	for (var i = 0; i < 18; i += 1) {
  	    var mod = (!test && ( (bits >> i) & 1) == 1);
  	    _modules[Math.floor(i / 3)][i % 3 + _moduleCount - 8 - 3] = mod;
  	}
  
  	for (var i = 0; i < 18; i += 1) {
  	    var mod = (!test && ( (bits >> i) & 1) == 1);
  	    _modules[i % 3 + _moduleCount - 8 - 3][Math.floor(i / 3)] = mod;
  	}
      };
  
      var setupTypeInfo = function(test, maskPattern) {
  
  	var data = (_errorCorrectLevel << 3) | maskPattern;
  	var bits = QRUtil.getBCHTypeInfo(data);
  
  	// vertical
  	for (var i = 0; i < 15; i += 1) {
  
  	    var mod = (!test && ( (bits >> i) & 1) == 1);
  
  	    if (i < 6) {
  		_modules[i][8] = mod;
  	    } else if (i < 8) {
  		_modules[i + 1][8] = mod;
  	    } else {
  		_modules[_moduleCount - 15 + i][8] = mod;
  	    }
  	}
  
  	// horizontal
  	for (var i = 0; i < 15; i += 1) {
  
  	    var mod = (!test && ( (bits >> i) & 1) == 1);
  
  	    if (i < 8) {
  		_modules[8][_moduleCount - i - 1] = mod;
  	    } else if (i < 9) {
  		_modules[8][15 - i - 1 + 1] = mod;
  	    } else {
  		_modules[8][15 - i - 1] = mod;
  	    }
  	}
  
  	// fixed module
  	_modules[_moduleCount - 8][8] = (!test);
      };
  
      var mapData = function(data, maskPattern) {
  
  	var inc = -1;
  	var row = _moduleCount - 1;
  	var bitIndex = 7;
  	var byteIndex = 0;
  	var maskFunc = QRUtil.getMaskFunction(maskPattern);
  
  	for (var col = _moduleCount - 1; col > 0; col -= 2) {
  
  	    if (col == 6) col -= 1;
  
  	    while (true) {
  
  		for (var c = 0; c < 2; c += 1) {
  
  		    if (_modules[row][col - c] == null) {
  
  			var dark = false;
  
  			if (byteIndex < data.length) {
  			    dark = ( ( (data[byteIndex] >>> bitIndex) & 1) == 1);
  			}
  
  			var mask = maskFunc(row, col - c);
  
  			if (mask) {
  			    dark = !dark;
  			}
  
  			_modules[row][col - c] = dark;
  			bitIndex -= 1;
  
  			if (bitIndex == -1) {
  			    byteIndex += 1;
  			    bitIndex = 7;
  			}
  		    }
  		}
  
  		row += inc;
  
  		if (row < 0 || _moduleCount <= row) {
  		    row -= inc;
  		    inc = -inc;
  		    break;
  		}
  	    }
  	}
      };
  
      var createBytes = function(buffer, rsBlocks) {
  
  	var offset = 0;
  
  	var maxDcCount = 0;
  	var maxEcCount = 0;
  
  	var dcdata = new Array(rsBlocks.length);
  	var ecdata = new Array(rsBlocks.length);
  
  	for (var r = 0; r < rsBlocks.length; r += 1) {
  
  	    var dcCount = rsBlocks[r].dataCount;
  	    var ecCount = rsBlocks[r].totalCount - dcCount;
  
  	    maxDcCount = Math.max(maxDcCount, dcCount);
  	    maxEcCount = Math.max(maxEcCount, ecCount);
  
  	    dcdata[r] = new Array(dcCount);
  
  	    for (var i = 0; i < dcdata[r].length; i += 1) {
  		dcdata[r][i] = 0xff & buffer.getBuffer()[i + offset];
  	    }
  	    offset += dcCount;
  
  	    var rsPoly = QRUtil.getErrorCorrectPolynomial(ecCount);
  	    var rawPoly = qrPolynomial(dcdata[r], rsPoly.getLength() - 1);
  
  	    var modPoly = rawPoly.mod(rsPoly);
  	    ecdata[r] = new Array(rsPoly.getLength() - 1);
  	    for (var i = 0; i < ecdata[r].length; i += 1) {
  		var modIndex = i + modPoly.getLength() - ecdata[r].length;
  		ecdata[r][i] = (modIndex >= 0)? modPoly.getAt(modIndex) : 0;
  	    }
  	}
  
  	var totalCodeCount = 0;
  	for (var i = 0; i < rsBlocks.length; i += 1) {
  	    totalCodeCount += rsBlocks[i].totalCount;
  	}
  
  	var data = new Array(totalCodeCount);
  	var index = 0;
  
  	for (var i = 0; i < maxDcCount; i += 1) {
  	    for (var r = 0; r < rsBlocks.length; r += 1) {
  		if (i < dcdata[r].length) {
  		    data[index] = dcdata[r][i];
  		    index += 1;
  		}
  	    }
  	}
  
  	for (var i = 0; i < maxEcCount; i += 1) {
  	    for (var r = 0; r < rsBlocks.length; r += 1) {
  		if (i < ecdata[r].length) {
  		    data[index] = ecdata[r][i];
  		    index += 1;
  		}
  	    }
  	}
  
  	return data;
      };
  
      var createData = function(typeNumber, errorCorrectLevel, dataList) {
  
  	var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, errorCorrectLevel);
  
  	var buffer = qrBitBuffer();
  
  	for (var i = 0; i < dataList.length; i += 1) {
  	    var data = dataList[i];
  	    buffer.put(data.getMode(), 4);
  	    buffer.put(data.getLength(), QRUtil.getLengthInBits(data.getMode(), typeNumber) );
  	    data.write(buffer);
  	}
  
  	// calc num max data.
  	var totalDataCount = 0;
  	for (var i = 0; i < rsBlocks.length; i += 1) {
  	    totalDataCount += rsBlocks[i].dataCount;
  	}
  
  	if (buffer.getLengthInBits() > totalDataCount * 8) {
  	    throw new Error('code length overflow. ('
  			    + buffer.getLengthInBits()
  			    + '>'
  			    + totalDataCount * 8
  			    + ')');
  	}
  
  	// end code
  	if (buffer.getLengthInBits() + 4 <= totalDataCount * 8) {
  	    buffer.put(0, 4);
  	}
  
  	// padding
  	while (buffer.getLengthInBits() % 8 != 0) {
  	    buffer.putBit(false);
  	}
  
  	// padding
  	while (true) {
  
  	    if (buffer.getLengthInBits() >= totalDataCount * 8) {
  		break;
  	    }
  	    buffer.put(PAD0, 8);
  
  	    if (buffer.getLengthInBits() >= totalDataCount * 8) {
  		break;
  	    }
  	    buffer.put(PAD1, 8);
  	}
  
  	return createBytes(buffer, rsBlocks);
      };
  
      _this.addData = function(data) {
  	var newData = qr8BitByte(data);
  	_dataList.push(newData);
  	_dataCache = null;
      };
  
      _this.isDark = function(row, col) {
  	if (row < 0 || _moduleCount <= row || col < 0 || _moduleCount <= col) {
  	    throw new Error(row + ',' + col);
  	}
  	return _modules[row][col];
      };
  
      _this.getModuleCount = function() {
  	return _moduleCount;
      };
  
      _this.make = function() {
  	makeImpl(false, getBestMaskPattern() );
      };
  
      _this.createTableTag = function(cellSize, margin) {
  
  	cellSize = cellSize || 2;
  	margin = (typeof margin == 'undefined')? cellSize * 4 : margin;
  
  	var qrHtml = '';
  
  	qrHtml += '<table style="';
  	qrHtml += ' border-width: 0px; border-style: none;';
  	qrHtml += ' border-collapse: collapse;';
  	qrHtml += ' padding: 0px; margin: ' + margin + 'px;';
  	qrHtml += '">';
  	qrHtml += '<tbody>';
  
  	for (var r = 0; r < _this.getModuleCount(); r += 1) {
  
  	    qrHtml += '<tr>';
  
  	    for (var c = 0; c < _this.getModuleCount(); c += 1) {
  		qrHtml += '<td style="';
  		qrHtml += ' border-width: 0px; border-style: none;';
  		qrHtml += ' border-collapse: collapse;';
  		qrHtml += ' padding: 0px; margin: 0px;';
  		qrHtml += ' width: ' + cellSize + 'px;';
  		qrHtml += ' height: ' + cellSize + 'px;';
  		qrHtml += ' background-color: ';
  		qrHtml += _this.isDark(r, c)? '#000000' : '#ffffff';
  		qrHtml += ';';
  		qrHtml += '"/>';
  	    }
  
  	    qrHtml += '</tr>';
  	}
  
  	qrHtml += '</tbody>';
  	qrHtml += '</table>';
  
  	return qrHtml;
      };
  
      _this.createImgTag = function(cellSize, margin, size) {
  
  	cellSize = cellSize || 2;
  	margin = (typeof margin == 'undefined')? cellSize * 4 : margin;
  
  	var min = margin;
  	var max = _this.getModuleCount() * cellSize + margin;
  
  	return createImgTag(size, size, function(x, y) {
  	    if (min <= x && x < max && min <= y && y < max) {
  		var c = Math.floor( (x - min) / cellSize);
  		var r = Math.floor( (y - min) / cellSize);
  		return _this.isDark(r, c)? 0 : 1;
  	    } else {
  		return 1;
  	    }
  	} );
      };
  
      return _this;
  };
  
  //---------------------------------------------------------------------
  // qrcode.stringToBytes
  //---------------------------------------------------------------------
  
  qrcode.stringToBytes = function(s) {
      var bytes = new Array();
      for (var i = 0; i < s.length; i += 1) {
  	var c = s.charCodeAt(i);
  	bytes.push(c & 0xff);
      }
      return bytes;
  };
  
  //---------------------------------------------------------------------
  // qrcode.createStringToBytes
  //---------------------------------------------------------------------
  
  /**
   * @param unicodeData base64 string of byte array.
   * [16bit Unicode],[16bit Bytes], ...
   * @param numChars
   */
  qrcode.createStringToBytes = function(unicodeData, numChars) {
  
      // create conversion map.
  
      var unicodeMap = function() {
  
  	var bin = base64DecodeInputStream(unicodeData);
  	var read = function() {
  	    var b = bin.read();
  	    if (b == -1) throw new Error();
  	    return b;
  	};
  
  	var count = 0;
  	var unicodeMap = {};
  	while (true) {
  	    var b0 = bin.read();
  	    if (b0 == -1) break;
  	    var b1 = read();
  	    var b2 = read();
  	    var b3 = read();
  	    var k = String.fromCharCode( (b0 << 8) | b1);
  	    var v = (b2 << 8) | b3;
  	    unicodeMap[k] = v;
  	    count += 1;
  	}
  	if (count != numChars) {
  	    throw new Error(count + ' != ' + numChars);
  	}
  
  	return unicodeMap;
      }();
  
      var unknownChar = '?'.charCodeAt(0);
  
      return function(s) {
  	var bytes = new Array();
  	for (var i = 0; i < s.length; i += 1) {
  	    var c = s.charCodeAt(i);
  	    if (c < 128) {
  		bytes.push(c);
  	    } else {
  		var b = unicodeMap[s.charAt(i)];
  		if (typeof b == 'number') {
  		    if ( (b & 0xff) == b) {
  			// 1byte
  			bytes.push(b);
  		    } else {
  			// 2bytes
  			bytes.push(b >>> 8);
  			bytes.push(b & 0xff);
  		    }
  		} else {
  		    bytes.push(unknownChar);
  		}
  	    }
  	}
  	return bytes;
      };
  };
  
  //---------------------------------------------------------------------
  // QRMode
  //---------------------------------------------------------------------
  
  var QRMode = {
      MODE_NUMBER :		1 << 0,
      MODE_ALPHA_NUM : 	1 << 1,
      MODE_8BIT_BYTE : 	1 << 2,
      MODE_KANJI :		1 << 3
  };
  
  //---------------------------------------------------------------------
  // QRErrorCorrectLevel
  //---------------------------------------------------------------------
  
  var QRErrorCorrectLevel = {
      L : 1,
      M : 0,
      Q : 3,
      H : 2
  };
  
  //---------------------------------------------------------------------
  // QRMaskPattern
  //---------------------------------------------------------------------
  
  var QRMaskPattern = {
      PATTERN000 : 0,
      PATTERN001 : 1,
      PATTERN010 : 2,
      PATTERN011 : 3,
      PATTERN100 : 4,
      PATTERN101 : 5,
      PATTERN110 : 6,
      PATTERN111 : 7
  };
  
  //---------------------------------------------------------------------
  // QRUtil
  //---------------------------------------------------------------------
  
  var QRUtil = function() {
  
      var PATTERN_POSITION_TABLE = [
  	[],
  	[6, 18],
  	[6, 22],
  	[6, 26],
  	[6, 30],
  	[6, 34],
  	[6, 22, 38],
  	[6, 24, 42],
  	[6, 26, 46],
  	[6, 28, 50],
  	[6, 30, 54],
  	[6, 32, 58],
  	[6, 34, 62],
  	[6, 26, 46, 66],
  	[6, 26, 48, 70],
  	[6, 26, 50, 74],
  	[6, 30, 54, 78],
  	[6, 30, 56, 82],
  	[6, 30, 58, 86],
  	[6, 34, 62, 90],
  	[6, 28, 50, 72, 94],
  	[6, 26, 50, 74, 98],
  	[6, 30, 54, 78, 102],
  	[6, 28, 54, 80, 106],
  	[6, 32, 58, 84, 110],
  	[6, 30, 58, 86, 114],
  	[6, 34, 62, 90, 118],
  	[6, 26, 50, 74, 98, 122],
  	[6, 30, 54, 78, 102, 126],
  	[6, 26, 52, 78, 104, 130],
  	[6, 30, 56, 82, 108, 134],
  	[6, 34, 60, 86, 112, 138],
  	[6, 30, 58, 86, 114, 142],
  	[6, 34, 62, 90, 118, 146],
  	[6, 30, 54, 78, 102, 126, 150],
  	[6, 24, 50, 76, 102, 128, 154],
  	[6, 28, 54, 80, 106, 132, 158],
  	[6, 32, 58, 84, 110, 136, 162],
  	[6, 26, 54, 82, 110, 138, 166],
  	[6, 30, 58, 86, 114, 142, 170]
      ];
      var G15 = (1 << 10) | (1 << 8) | (1 << 5) | (1 << 4) | (1 << 2) | (1 << 1) | (1 << 0);
      var G18 = (1 << 12) | (1 << 11) | (1 << 10) | (1 << 9) | (1 << 8) | (1 << 5) | (1 << 2) | (1 << 0);
      var G15_MASK = (1 << 14) | (1 << 12) | (1 << 10) | (1 << 4) | (1 << 1);
  
      var _this = {};
  
      var getBCHDigit = function(data) {
  	var digit = 0;
  	while (data != 0) {
  	    digit += 1;
  	    data >>>= 1;
  	}
  	return digit;
      };
  
      _this.getBCHTypeInfo = function(data) {
  	var d = data << 10;
  	while (getBCHDigit(d) - getBCHDigit(G15) >= 0) {
  	    d ^= (G15 << (getBCHDigit(d) - getBCHDigit(G15) ) );
  	}
  	return ( (data << 10) | d) ^ G15_MASK;
      };
  
      _this.getBCHTypeNumber = function(data) {
  	var d = data << 12;
  	while (getBCHDigit(d) - getBCHDigit(G18) >= 0) {
  	    d ^= (G18 << (getBCHDigit(d) - getBCHDigit(G18) ) );
  	}
  	return (data << 12) | d;
      };
  
      _this.getPatternPosition = function(typeNumber) {
  	return PATTERN_POSITION_TABLE[typeNumber - 1];
      };
  
      _this.getMaskFunction = function(maskPattern) {
  
  	switch (maskPattern) {
  
  	    case QRMaskPattern.PATTERN000 :
  		return function(i, j) { return (i + j) % 2 == 0; };
  	    case QRMaskPattern.PATTERN001 :
  		return function(i, j) { return i % 2 == 0; };
  	    case QRMaskPattern.PATTERN010 :
  		return function(i, j) { return j % 3 == 0; };
  	    case QRMaskPattern.PATTERN011 :
  		return function(i, j) { return (i + j) % 3 == 0; };
  	    case QRMaskPattern.PATTERN100 :
  		return function(i, j) { return (Math.floor(i / 2) + Math.floor(j / 3) ) % 2 == 0; };
  	    case QRMaskPattern.PATTERN101 :
  		return function(i, j) { return (i * j) % 2 + (i * j) % 3 == 0; };
  	    case QRMaskPattern.PATTERN110 :
  		return function(i, j) { return ( (i * j) % 2 + (i * j) % 3) % 2 == 0; };
  	    case QRMaskPattern.PATTERN111 :
  		return function(i, j) { return ( (i * j) % 3 + (i + j) % 2) % 2 == 0; };
  
  		default :
  		throw new Error('bad maskPattern:' + maskPattern);
  	}
      };
  
      _this.getErrorCorrectPolynomial = function(errorCorrectLength) {
  	var a = qrPolynomial([1], 0);
  	for (var i = 0; i < errorCorrectLength; i += 1) {
  	    a = a.multiply(qrPolynomial([1, QRMath.gexp(i)], 0) );
  	}
  	return a;
      };
  
      _this.getLengthInBits = function(mode, type) {
  
  	if (1 <= type && type < 10) {
  
  	    // 1 - 9
  
  	    switch(mode) {
  		case QRMode.MODE_NUMBER 	: return 10;
  		case QRMode.MODE_ALPHA_NUM 	: return 9;
  		case QRMode.MODE_8BIT_BYTE	: return 8;
  		case QRMode.MODE_KANJI		: return 8;
  		    default :
  		    throw new Error('mode:' + mode);
  	    }
  
  	} else if (type < 27) {
  
  	    // 10 - 26
  
  	    switch(mode) {
  		case QRMode.MODE_NUMBER 	: return 12;
  		case QRMode.MODE_ALPHA_NUM 	: return 11;
  		case QRMode.MODE_8BIT_BYTE	: return 16;
  		case QRMode.MODE_KANJI		: return 10;
  		    default :
  		    throw new Error('mode:' + mode);
  	    }
  
  	} else if (type < 41) {
  
  	    // 27 - 40
  
  	    switch(mode) {
  		case QRMode.MODE_NUMBER 	: return 14;
  		case QRMode.MODE_ALPHA_NUM	: return 13;
  		case QRMode.MODE_8BIT_BYTE	: return 16;
  		case QRMode.MODE_KANJI		: return 12;
  		    default :
  		    throw new Error('mode:' + mode);
  	    }
  
  	} else {
  	    throw new Error('type:' + type);
  	}
      };
  
      _this.getLostPoint = function(qrcode) {
  
  	var moduleCount = qrcode.getModuleCount();
  
  	var lostPoint = 0;
  
  	// LEVEL1
  
  	for (var row = 0; row < moduleCount; row += 1) {
  	    for (var col = 0; col < moduleCount; col += 1) {
  
  		var sameCount = 0;
  		var dark = qrcode.isDark(row, col);
  
  		for (var r = -1; r <= 1; r += 1) {
  
  		    if (row + r < 0 || moduleCount <= row + r) {
  			continue;
  		    }
  
  		    for (var c = -1; c <= 1; c += 1) {
  
  			if (col + c < 0 || moduleCount <= col + c) {
  			    continue;
  			}
  
  			if (r == 0 && c == 0) {
  			    continue;
  			}
  
  			if (dark == qrcode.isDark(row + r, col + c) ) {
  			    sameCount += 1;
  			}
  		    }
  		}
  
  		if (sameCount > 5) {
  		    lostPoint += (3 + sameCount - 5);
  		}
  	    }
  	};
  
  	// LEVEL2
  
  	for (var row = 0; row < moduleCount - 1; row += 1) {
  	    for (var col = 0; col < moduleCount - 1; col += 1) {
  		var count = 0;
  		if (qrcode.isDark(row, col) ) count += 1;
  		if (qrcode.isDark(row + 1, col) ) count += 1;
  		if (qrcode.isDark(row, col + 1) ) count += 1;
  		if (qrcode.isDark(row + 1, col + 1) ) count += 1;
  		if (count == 0 || count == 4) {
  		    lostPoint += 3;
  		}
  	    }
  	}
  
  	// LEVEL3
  
  	for (var row = 0; row < moduleCount; row += 1) {
  	    for (var col = 0; col < moduleCount - 6; col += 1) {
  		if (qrcode.isDark(row, col)
  		    && !qrcode.isDark(row, col + 1)
  		    &&  qrcode.isDark(row, col + 2)
  		    &&  qrcode.isDark(row, col + 3)
  		    &&  qrcode.isDark(row, col + 4)
  		    && !qrcode.isDark(row, col + 5)
  		    &&  qrcode.isDark(row, col + 6) ) {
  		    lostPoint += 40;
  		}
  	    }
  	}
  
  	for (var col = 0; col < moduleCount; col += 1) {
  	    for (var row = 0; row < moduleCount - 6; row += 1) {
  		if (qrcode.isDark(row, col)
  		    && !qrcode.isDark(row + 1, col)
  		    &&  qrcode.isDark(row + 2, col)
  		    &&  qrcode.isDark(row + 3, col)
  		    &&  qrcode.isDark(row + 4, col)
  		    && !qrcode.isDark(row + 5, col)
  		    &&  qrcode.isDark(row + 6, col) ) {
  		    lostPoint += 40;
  		}
  	    }
  	}
  
  	// LEVEL4
  
  	var darkCount = 0;
  
  	for (var col = 0; col < moduleCount; col += 1) {
  	    for (var row = 0; row < moduleCount; row += 1) {
  		if (qrcode.isDark(row, col) ) {
  		    darkCount += 1;
  		}
  	    }
  	}
  
  	var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5;
  	lostPoint += ratio * 10;
  
  	return lostPoint;
      };
  
      return _this;
  }();
  
  //---------------------------------------------------------------------
  // QRMath
  //---------------------------------------------------------------------
  
  var QRMath = function() {
  
      var EXP_TABLE = new Array(256);
      var LOG_TABLE = new Array(256);
  
      // initialize tables
      for (var i = 0; i < 8; i += 1) {
  	EXP_TABLE[i] = 1 << i;
      }
      for (var i = 8; i < 256; i += 1) {
  	EXP_TABLE[i] = EXP_TABLE[i - 4]
  	    ^ EXP_TABLE[i - 5]
  	    ^ EXP_TABLE[i - 6]
  	    ^ EXP_TABLE[i - 8];
      }
      for (var i = 0; i < 255; i += 1) {
  	LOG_TABLE[EXP_TABLE[i] ] = i;
      }
  
      var _this = {};
  
      _this.glog = function(n) {
  
  	if (n < 1) {
  	    throw new Error('glog(' + n + ')');
  	}
  
  	return LOG_TABLE[n];
      };
  
      _this.gexp = function(n) {
  
  	while (n < 0) {
  	    n += 255;
  	}
  
  	while (n >= 256) {
  	    n -= 255;
  	}
  
  	return EXP_TABLE[n];
      };
  
      return _this;
  }();
  
  //---------------------------------------------------------------------
  // qrPolynomial
  //---------------------------------------------------------------------
  
  function qrPolynomial(num, shift) {
  
      if (typeof num.length == 'undefined') {
  	throw new Error(num.length + '/' + shift);
      }
  
      var _num = function() {
  	var offset = 0;
  	while (offset < num.length && num[offset] == 0) {
  	    offset += 1;
  	}
  	var _num = new Array(num.length - offset + shift);
  	for (var i = 0; i < num.length - offset; i += 1) {
  	    _num[i] = num[i + offset];
  	}
  	return _num;
      }();
  
      var _this = {};
  
      _this.getAt = function(index) {
  	return _num[index];
      };
  
      _this.getLength = function() {
  	return _num.length;
      };
  
      _this.multiply = function(e) {
  
  	var num = new Array(_this.getLength() + e.getLength() - 1);
  
  	for (var i = 0; i < _this.getLength(); i += 1) {
  	    for (var j = 0; j < e.getLength(); j += 1) {
  		num[i + j] ^= QRMath.gexp(QRMath.glog(_this.getAt(i) ) + QRMath.glog(e.getAt(j) ) );
  	    }
  	}
  
  	return qrPolynomial(num, 0);
      };
  
      _this.mod = function(e) {
  
  	if (_this.getLength() - e.getLength() < 0) {
  	    return _this;
  	}
  
  	var ratio = QRMath.glog(_this.getAt(0) ) - QRMath.glog(e.getAt(0) );
  
  	var num = new Array(_this.getLength() );
  	for (var i = 0; i < _this.getLength(); i += 1) {
  	    num[i] = _this.getAt(i);
  	}
  
  	for (var i = 0; i < e.getLength(); i += 1) {
  	    num[i] ^= QRMath.gexp(QRMath.glog(e.getAt(i) ) + ratio);
  	}
  
  	// recursive call
  	return qrPolynomial(num, 0).mod(e);
      };
  
      return _this;
  };
  
  //---------------------------------------------------------------------
  // QRRSBlock
  //---------------------------------------------------------------------
  
  var QRRSBlock = function() {
  
  
      // [1: [L, M, Q, H], ..]
      var RS_BLOCK_TABLE=[[1,26,19],[1,26,16],[1,26,13],[1,26,9],[1,44,34],[1,44,28],[1,44,22],[1,44,16],[1,70,55],[1,70,44],[2,35,17],[2,35,13],[1,100,80],[2,50,32],[2,50,24],[4,25,9],[1,134,108],[2,67,43],[2,33,15,2,34,16],[2,33,11,2,34,12],[2,86,68],[4,43,27],[4,43,19],[4,43,15],[2,98,78],[4,49,31],[2,32,14,4,33,15],[4,39,13,1,40,14],[2,121,97],[2,60,38,2,61,39],[4,40,18,2,41,19],[4,40,14,2,41,15],[2,146,116],[3,58,36,2,59,37],[4,36,16,4,37,17],[4,36,12,4,37,13],[2,86,68,2,87,69],[4,69,43,1,70,44],[6,43,19,2,44,20],[6,43,15,2,44,16],[4,101,81],[1,80,50,4,81,51],[4,50,22,4,51,23],[3,36,12,8,37,13],[2,116,92,2,117,93],[6,58,36,2,59,37],[4,46,20,6,47,21],[7,42,14,4,43,15],[4,133,107],[8,59,37,1,60,38],[8,44,20,4,45,21],[12,33,11,4,34,12],[3,145,115,1,146,116],[4,64,40,5,65,41],[11,36,16,5,37,17],[11,36,12,5,37,13],[5,109,87,1,110,88],[5,65,41,5,66,42],[5,54,24,7,55,25],[11,36,12],[5,122,98,1,123,99],[7,73,45,3,74,46],[15,43,19,2,44,20],[3,45,15,13,46,16],[1,135,107,5,136,108],[10,74,46,1,75,47],[1,50,22,15,51,23],[2,42,14,17,43,15],[5,150,120,1,151,121],[9,69,43,4,70,44],[17,50,22,1,51,23],[2,42,14,19,43,15],[3,141,113,4,142,114],[3,70,44,11,71,45],[17,47,21,4,48,22],[9,39,13,16,40,14],[3,135,107,5,136,108],[3,67,41,13,68,42],[15,54,24,5,55,25],[15,43,15,10,44,16],[4,144,116,4,145,117],[17,68,42],[17,50,22,6,51,23],[19,46,16,6,47,17],[2,139,111,7,140,112],[17,74,46],[7,54,24,16,55,25],[34,37,13],[4,151,121,5,152,122],[4,75,47,14,76,48],[11,54,24,14,55,25],[16,45,15,14,46,16],[6,147,117,4,148,118],[6,73,45,14,74,46],[11,54,24,16,55,25],[30,46,16,2,47,17],[8,132,106,4,133,107],[8,75,47,13,76,48],[7,54,24,22,55,25],[22,45,15,13,46,16],[10,142,114,2,143,115],[19,74,46,4,75,47],[28,50,22,6,51,23],[33,46,16,4,47,17],[8,152,122,4,153,123],[22,73,45,3,74,46],[8,53,23,26,54,24],[12,45,15,28,46,16],[3,147,117,10,148,118],[3,73,45,23,74,46],[4,54,24,31,55,25],[11,45,15,31,46,16],[7,146,116,7,147,117],[21,73,45,7,74,46],[1,53,23,37,54,24],[19,45,15,26,46,16],[5,145,115,10,146,116],[19,75,47,10,76,48],[15,54,24,25,55,25],[23,45,15,25,46,16],[13,145,115,3,146,116],[2,74,46,29,75,47],[42,54,24,1,55,25],[23,45,15,28,46,16],[17,145,115],[10,74,46,23,75,47],[10,54,24,35,55,25],[19,45,15,35,46,16],[17,145,115,1,146,116],[14,74,46,21,75,47],[29,54,24,19,55,25],[11,45,15,46,46,16],[13,145,115,6,146,116],[14,74,46,23,75,47],[44,54,24,7,55,25],[59,46,16,1,47,17],[12,151,121,7,152,122],[12,75,47,26,76,48],[39,54,24,14,55,25],[22,45,15,41,46,16],[6,151,121,14,152,122],[6,75,47,34,76,48],[46,54,24,10,55,25],[2,45,15,64,46,16],[17,152,122,4,153,123],[29,74,46,14,75,47],[49,54,24,10,55,25],[24,45,15,46,46,16],[4,152,122,18,153,123],[13,74,46,32,75,47],[48,54,24,14,55,25],[42,45,15,32,46,16],[20,147,117,4,148,118],[40,75,47,7,76,48],[43,54,24,22,55,25],[10,45,15,67,46,16],[19,148,118,6,149,119],[18,75,47,31,76,48],[34,54,24,34,55,25],[20,45,15,61,46,16]];
  
      var qrRSBlock = function(totalCount, dataCount) {
  	var _this = {};
  	_this.totalCount = totalCount;
  	_this.dataCount = dataCount;
  	return _this;
      };
  
      var _this = {};
  
      var getRsBlockTable = function(typeNumber, errorCorrectLevel) {
  
  	switch(errorCorrectLevel) {
  	    case QRErrorCorrectLevel.L :
  		return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 0];
  	    case QRErrorCorrectLevel.M :
  		return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 1];
  	    case QRErrorCorrectLevel.Q :
  		return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 2];
  	    case QRErrorCorrectLevel.H :
  		return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 3];
  		default :
  		return undefined;
  	}
      };
  
      _this.getRSBlocks = function(typeNumber, errorCorrectLevel) {
  
  	var rsBlock = getRsBlockTable(typeNumber, errorCorrectLevel);
  
  	if (typeof rsBlock == 'undefined') {
  	    throw new Error('bad rs block @ typeNumber:' + typeNumber +
  			    '/errorCorrectLevel:' + errorCorrectLevel);
  	}
  
  	var length = rsBlock.length / 3;
  
  	var list = new Array();
  
  	for (var i = 0; i < length; i += 1) {
  
  	    var count = rsBlock[i * 3 + 0];
  	    var totalCount = rsBlock[i * 3 + 1];
  	    var dataCount = rsBlock[i * 3 + 2];
  
  	    for (var j = 0; j < count; j += 1) {
  		list.push(qrRSBlock(totalCount, dataCount) );
  	    }
  	}
  
  	return list;
      };
  
      return _this;
  }();
  
  //---------------------------------------------------------------------
  // qrBitBuffer
  //---------------------------------------------------------------------
  
  var qrBitBuffer = function() {
  
      var _buffer = new Array();
      var _length = 0;
  
      var _this = {};
  
      _this.getBuffer = function() {
  	return _buffer;
      };
  
      _this.getAt = function(index) {
  	var bufIndex = Math.floor(index / 8);
  	return ( (_buffer[bufIndex] >>> (7 - index % 8) ) & 1) == 1;
      };
  
      _this.put = function(num, length) {
  	for (var i = 0; i < length; i += 1) {
  	    _this.putBit( ( (num >>> (length - i - 1) ) & 1) == 1);
  	}
      };
  
      _this.getLengthInBits = function() {
  	return _length;
      };
  
      _this.putBit = function(bit) {
  
  	var bufIndex = Math.floor(_length / 8);
  	if (_buffer.length <= bufIndex) {
  	    _buffer.push(0);
  	}
  
  	if (bit) {
  	    _buffer[bufIndex] |= (0x80 >>> (_length % 8) );
  	}
  
  	_length += 1;
      };
  
      return _this;
  };
  
  //---------------------------------------------------------------------
  // qr8BitByte
  //---------------------------------------------------------------------
  
  var qr8BitByte = function(data) {
  
      var _mode = QRMode.MODE_8BIT_BYTE;
      var _data = data;
      var _parsedData = [];
  
      var _this = {};
  
  
      // Added to support UTF-8 Characters
      for (var i = 0, l = _data.length; i < l; i++) {
  	var byteArray = [];
  	var code = _data.charCodeAt(i);
  
  	if (code > 0x10000) {
  	    byteArray[0] = 0xF0 | ((code & 0x1C0000) >>> 18);
  	    byteArray[1] = 0x80 | ((code & 0x3F000) >>> 12);
  	    byteArray[2] = 0x80 | ((code & 0xFC0) >>> 6);
  	    byteArray[3] = 0x80 | (code & 0x3F);
  	} else if (code > 0x800) {
  	    byteArray[0] = 0xE0 | ((code & 0xF000) >>> 12);
  	    byteArray[1] = 0x80 | ((code & 0xFC0) >>> 6);
  	    byteArray[2] = 0x80 | (code & 0x3F);
  	} else if (code > 0x80) {
  	    byteArray[0] = 0xC0 | ((code & 0x7C0) >>> 6);
  	    byteArray[1] = 0x80 | (code & 0x3F);
  	} else {
  	    byteArray[0] = code;
  	}
  
          // Fix Unicode corruption bug
          _parsedData.push(byteArray);
      }
  
      _parsedData = Array.prototype.concat.apply([], _parsedData);
  
      if (_parsedData.length != _data.length) {
  	_parsedData.unshift(191);
  	_parsedData.unshift(187);
  	_parsedData.unshift(239);
      }
  
      var _bytes = _parsedData;
  
      _this.getMode = function() {
  	return _mode;
      };
  
      _this.getLength = function(buffer) {
  	return _bytes.length;
      };
  
      _this.write = function(buffer) {
  	for (var i = 0; i < _bytes.length; i += 1) {
  	    buffer.put(_bytes[i], 8);
  	}
      };
  
      return _this;
  };
  
  //=====================================================================
  // GIF Support etc.
  //
  
  //---------------------------------------------------------------------
  // byteArrayOutputStream
  //---------------------------------------------------------------------
  
  var byteArrayOutputStream = function() {
  
      var _bytes = new Array();
  
      var _this = {};
  
      _this.writeByte = function(b) {
  	_bytes.push(b & 0xff);
      };
  
      _this.writeShort = function(i) {
  	_this.writeByte(i);
  	_this.writeByte(i >>> 8);
      };
  
      _this.writeBytes = function(b, off, len) {
  	off = off || 0;
  	len = len || b.length;
  	for (var i = 0; i < len; i += 1) {
  	    _this.writeByte(b[i + off]);
  	}
      };
  
      _this.writeString = function(s) {
  	for (var i = 0; i < s.length; i += 1) {
  	    _this.writeByte(s.charCodeAt(i) );
  	}
      };
  
      _this.toByteArray = function() {
  	return _bytes;
      };
  
      _this.toString = function() {
  	var s = '';
  	s += '[';
  	for (var i = 0; i < _bytes.length; i += 1) {
  	    if (i > 0) {
  		s += ',';
  	    }
  	    s += _bytes[i];
  	}
  	s += ']';
  	return s;
      };
  
      return _this;
  };
  
  //---------------------------------------------------------------------
  // base64EncodeOutputStream
  //---------------------------------------------------------------------
  
  var base64EncodeOutputStream = function() {
  
      var _buffer = 0;
      var _buflen = 0;
      var _length = 0;
      var _base64 = '';
  
      var _this = {};
  
      var writeEncoded = function(b) {
  	_base64 += String.fromCharCode(encode(b & 0x3f) );
      };
  
      var encode = function(n) {
  	if (n < 0) {
  	    // error.
  	} else if (n < 26) {
  	    return 0x41 + n;
  	} else if (n < 52) {
  	    return 0x61 + (n - 26);
  	} else if (n < 62) {
  	    return 0x30 + (n - 52);
  	} else if (n == 62) {
  	    return 0x2b;
  	} else if (n == 63) {
  	    return 0x2f;
  	}
  	throw new Error('n:' + n);
      };
  
      _this.writeByte = function(n) {
  
  	_buffer = (_buffer << 8) | (n & 0xff);
  	_buflen += 8;
  	_length += 1;
  
  	while (_buflen >= 6) {
  	    writeEncoded(_buffer >>> (_buflen - 6) );
  	    _buflen -= 6;
  	}
      };
  
      _this.flush = function() {
  
  	if (_buflen > 0) {
  	    writeEncoded(_buffer << (6 - _buflen) );
  	    _buffer = 0;
  	    _buflen = 0;
  	}
  
  	if (_length % 3 != 0) {
  	    // padding
  	    var padlen = 3 - _length % 3;
  	    for (var i = 0; i < padlen; i += 1) {
  		_base64 += '=';
  	    }
  	}
      };
  
      _this.toString = function() {
  	return _base64;
      };
  
      return _this;
  };
  
  //---------------------------------------------------------------------
  // base64DecodeInputStream
  //---------------------------------------------------------------------
  
  var base64DecodeInputStream = function(str) {
  
      var _str = str;
      var _pos = 0;
      var _buffer = 0;
      var _buflen = 0;
  
      var _this = {};
  
      _this.read = function() {
  
  	while (_buflen < 8) {
  
  	    if (_pos >= _str.length) {
  		if (_buflen == 0) {
  		    return -1;
  		}
  		throw new Error('unexpected end of file./' + _buflen);
  	    }
  
  	    var c = _str.charAt(_pos);
  	    _pos += 1;
  
  	    if (c == '=') {
  		_buflen = 0;
  		return -1;
  	    } else if (c.match(/^\s$/) ) {
  		// ignore if whitespace.
  		continue;
  	    }
  
  	    _buffer = (_buffer << 6) | decode(c.charCodeAt(0) );
  	    _buflen += 6;
  	}
  
  	var n = (_buffer >>> (_buflen - 8) ) & 0xff;
  	_buflen -= 8;
  	return n;
      };
  
      var decode = function(c) {
  	if (0x41 <= c && c <= 0x5a) {
  	    return c - 0x41;
  	} else if (0x61 <= c && c <= 0x7a) {
  	    return c - 0x61 + 26;
  	} else if (0x30 <= c && c <= 0x39) {
  	    return c - 0x30 + 52;
  	} else if (c == 0x2b) {
  	    return 62;
  	} else if (c == 0x2f) {
  	    return 63;
  	} else {
  	    throw new Error('c:' + c);
  	}
      };
  
      return _this;
  };
  
  //---------------------------------------------------------------------
  // gifImage (B/W)
  //---------------------------------------------------------------------
  
  var gifImage = function(width, height) {
  
      var _width = width;
      var _height = height;
      var _data = new Array(width * height);
  
      var _this = {};
  
      _this.setPixel = function(x, y, pixel) {
  	_data[y * _width + x] = pixel;
      };
  
      _this.write = function(out) {
  
  	//---------------------------------
  	// GIF Signature
  
  	out.writeString('GIF87a');
  
  	//---------------------------------
  	// Screen Descriptor
  
  	out.writeShort(_width);
  	out.writeShort(_height);
  
  	out.writeByte(0x80); // 2bit
  	out.writeByte(0);
  	out.writeByte(0);
  
  	//---------------------------------
  	// Global Color Map
  
  	// black
  	out.writeByte(0x00);
  	out.writeByte(0x00);
  	out.writeByte(0x00);
  
  	// white
  	out.writeByte(0xff);
  	out.writeByte(0xff);
  	out.writeByte(0xff);
  
  	//---------------------------------
  	// Image Descriptor
  
  	out.writeString(',');
  	out.writeShort(0);
  	out.writeShort(0);
  	out.writeShort(_width);
  	out.writeShort(_height);
  	out.writeByte(0);
  
  	//---------------------------------
  	// Local Color Map
  
  	//---------------------------------
  	// Raster Data
  
  	var lzwMinCodeSize = 2;
  	var raster = getLZWRaster(lzwMinCodeSize);
  
  	out.writeByte(lzwMinCodeSize);
  
  	var offset = 0;
  
  	while (raster.length - offset > 255) {
  	    out.writeByte(255);
  	    out.writeBytes(raster, offset, 255);
  	    offset += 255;
  	}
  
  	out.writeByte(raster.length - offset);
  	out.writeBytes(raster, offset, raster.length - offset);
  	out.writeByte(0x00);
  
  	//---------------------------------
  	// GIF Terminator
  	out.writeString(';');
      };
  
      var bitOutputStream = function(out) {
  
  	var _out = out;
  	var _bitLength = 0;
  	var _bitBuffer = 0;
  
  	var _this = {};
  
  	_this.write = function(data, length) {
  
  	    if ( (data >>> length) != 0) {
  		throw new Error('length over');
  	    }
  
  	    while (_bitLength + length >= 8) {
  		_out.writeByte(0xff & ( (data << _bitLength) | _bitBuffer) );
  		length -= (8 - _bitLength);
  		data >>>= (8 - _bitLength);
  		_bitBuffer = 0;
  		_bitLength = 0;
  	    }
  
  	    _bitBuffer = (data << _bitLength) | _bitBuffer;
  	    _bitLength = _bitLength + length;
  	};
  
  	_this.flush = function() {
  	    if (_bitLength > 0) {
  		_out.writeByte(_bitBuffer);
  	    }
  	};
  
  	return _this;
      };
  
      var getLZWRaster = function(lzwMinCodeSize) {
  
  	var clearCode = 1 << lzwMinCodeSize;
  	var endCode = (1 << lzwMinCodeSize) + 1;
  	var bitLength = lzwMinCodeSize + 1;
  
  	// Setup LZWTable
  	var table = lzwTable();
  
  	for (var i = 0; i < clearCode; i += 1) {
  	    table.add(String.fromCharCode(i) );
  	}
  	table.add(String.fromCharCode(clearCode) );
  	table.add(String.fromCharCode(endCode) );
  
  	var byteOut = byteArrayOutputStream();
  	var bitOut = bitOutputStream(byteOut);
  
  	// clear code
  	bitOut.write(clearCode, bitLength);
  
  	var dataIndex = 0;
  
  	var s = String.fromCharCode(_data[dataIndex]);
  	dataIndex += 1;
  
  	while (dataIndex < _data.length) {
  
  	    var c = String.fromCharCode(_data[dataIndex]);
  	    dataIndex += 1;
  
  	    if (table.contains(s + c) ) {
  
  		s = s + c;
  
  	    } else {
  
  		bitOut.write(table.indexOf(s), bitLength);
  
  		if (table.size() < 0xfff) {
  
  		    if (table.size() == (1 << bitLength) ) {
  			bitLength += 1;
  		    }
  
  		    table.add(s + c);
  		}
  
  		s = c;
  	    }
  	}
  
  	bitOut.write(table.indexOf(s), bitLength);
  
  	// end code
  	bitOut.write(endCode, bitLength);
  
  	bitOut.flush();
  
  	return byteOut.toByteArray();
      };
  
      var lzwTable = function() {
  
  	var _map = {};
  	var _size = 0;
  
  	var _this = {};
  
  	_this.add = function(key) {
  	    if (_this.contains(key) ) {
  		throw new Error('dup key:' + key);
  	    }
  	    _map[key] = _size;
  	    _size += 1;
  	};
  
  	_this.size = function() {
  	    return _size;
  	};
  
  	_this.indexOf = function(key) {
  	    return _map[key];
  	};
  
  	_this.contains = function(key) {
  	    return typeof _map[key] != 'undefined';
  	};
  
  	return _this;
      };
  
      return _this;
  };
  
  var createImgTag = function(width, height, getPixel, alt) {
  
      var gif = gifImage(width, height);
      for (var y = 0; y < height; y += 1) {
  	for (var x = 0; x < width; x += 1) {
  	    gif.setPixel(x, y, getPixel(x, y) );
  	}
      }
  
      var b = byteArrayOutputStream();
      gif.write(b);
  
      var base64 = base64EncodeOutputStream();
      var bytes = b.toByteArray();
      for (var i = 0; i < bytes.length; i += 1) {
  	base64.writeByte(bytes[i]);
      }
      base64.flush();
  
      var img = '';
      img += 'data:image/gif;base64,';
      img += base64;
  
      return img;
  };
  
  //---------------------------------------------------------------------
  // returns qrcode function.
  
  var drawImg = function(text, options) {
      options = options || {};
      var typeNumber = options.typeNumber || 4;
      var errorCorrectLevel = options.errorCorrectLevel || 'M';
      var size = options.size || 500;
  
      var qr;
  
      try {
          qr = qrcode(typeNumber, errorCorrectLevel || 'M');
          qr.addData(text);
          qr.make();
      } catch (e) {
          if(typeNumber >= 40) {
              throw new Error('Text too long to encode');
          } else {
              return drawImg(text, {
                  size: size,
                  errorCorrectLevel: errorCorrectLevel,
                  typeNumber: typeNumber + 1
              });
          }
      }
  
      // calc cellsize and margin
      var cellsize = parseInt(size / qr.getModuleCount());
      var margin = parseInt((size - qr.getModuleCount() * cellsize) / 2);
  
      return qr.createImgTag(cellsize, margin, size);
  };
  module.exports = {
  	drawImg: drawImg
  };