(function() {

	var debug = false;

	var root = this;

	var EXIF = function(obj) {
		if (obj instanceof EXIF) return obj;
		if (!(this instanceof EXIF)) return new EXIF(obj);
		this.EXIFwrapped = obj;
	};

	if (typeof exports !== 'undefined') {
		if (typeof module !== 'undefined' && module.exports) {
			exports = module.exports = EXIF;
		}
		exports.EXIF = EXIF;
	} else {
		root.EXIF = EXIF;
	}

	var ExifTags = EXIF.Tags = {

		// version tags
		0x9000 : "ExifVersion",             // EXIF version
		0xA000 : "FlashpixVersion",         // Flashpix format version

		// colorspace tags
		0xA001 : "ColorSpace",              // Color space information tag

		// image configuration
		0xA002 : "PixelXDimension",         // Valid width of meaningful image
		0xA003 : "PixelYDimension",         // Valid height of meaningful image
		0x9101 : "ComponentsConfiguration", // Information about channels
		0x9102 : "CompressedBitsPerPixel",  // Compressed bits per pixel

		// user information
		0x927C : "MakerNote",               // Any desired information written by the manufacturer
		0x9286 : "UserComment",             // Comments by user

		// related file
		0xA004 : "RelatedSoundFile",        // Name of related sound file

		// date and time
		0x9003 : "DateTimeOriginal",        // Date and time when the original image was generated
		0x9004 : "DateTimeDigitized",       // Date and time when the image was stored digitally
		0x9290 : "SubsecTime",              // Fractions of seconds for DateTime
		0x9291 : "SubsecTimeOriginal",      // Fractions of seconds for DateTimeOriginal
		0x9292 : "SubsecTimeDigitized",     // Fractions of seconds for DateTimeDigitized

		// picture-taking conditions
		0x829A : "ExposureTime",            // Exposure time (in seconds)
		0x829D : "FNumber",                 // F number
		0x8822 : "ExposureProgram",         // Exposure program
		0x8824 : "SpectralSensitivity",     // Spectral sensitivity
		0x8827 : "ISOSpeedRatings",         // ISO speed rating
		0x8828 : "OECF",                    // Optoelectric conversion factor
		0x9201 : "ShutterSpeedValue",       // Shutter speed
		0x9202 : "ApertureValue",           // Lens aperture
		0x9203 : "BrightnessValue",         // Value of brightness
		0x9204 : "ExposureBias",            // Exposure bias
		0x9205 : "MaxApertureValue",        // Smallest F number of lens
		0x9206 : "SubjectDistance",         // Distance to subject in meters
		0x9207 : "MeteringMode",            // Metering mode
		0x9208 : "LightSource",             // Kind of light source
		0x9209 : "Flash",                   // Flash status
		0x9214 : "SubjectArea",             // Location and area of main subject
		0x920A : "FocalLength",             // Focal length of the lens in mm
		0xA20B : "FlashEnergy",             // Strobe energy in BCPS
		0xA20C : "SpatialFrequencyResponse",    //
		0xA20E : "FocalPlaneXResolution",   // Number of pixels in width direction per FocalPlaneResolutionUnit
		0xA20F : "FocalPlaneYResolution",   // Number of pixels in height direction per FocalPlaneResolutionUnit
		0xA210 : "FocalPlaneResolutionUnit",    // Unit for measuring FocalPlaneXResolution and FocalPlaneYResolution
		0xA214 : "SubjectLocation",         // Location of subject in image
		0xA215 : "ExposureIndex",           // Exposure index selected on camera
		0xA217 : "SensingMethod",           // Image sensor type
		0xA300 : "FileSource",              // Image source (3 == DSC)
		0xA301 : "SceneType",               // Scene type (1 == directly photographed)
		0xA302 : "CFAPattern",              // Color filter array geometric pattern
		0xA401 : "CustomRendered",          // Special processing
		0xA402 : "ExposureMode",            // Exposure mode
		0xA403 : "WhiteBalance",            // 1 = auto white balance, 2 = manual
		0xA404 : "DigitalZoomRation",       // Digital zoom ratio
		0xA405 : "FocalLengthIn35mmFilm",   // Equivalent foacl length assuming 35mm film camera (in mm)
		0xA406 : "SceneCaptureType",        // Type of scene
		0xA407 : "GainControl",             // Degree of overall image gain adjustment
		0xA408 : "Contrast",                // Direction of contrast processing applied by camera
		0xA409 : "Saturation",              // Direction of saturation processing applied by camera
		0xA40A : "Sharpness",               // Direction of sharpness processing applied by camera
		0xA40B : "DeviceSettingDescription",    //
		0xA40C : "SubjectDistanceRange",    // Distance to subject

		// other tags
		0xA005 : "InteroperabilityIFDPointer",
		0xA420 : "ImageUniqueID"            // Identifier assigned uniquely to each image
	};

	var TiffTags = EXIF.TiffTags = {
		0x0100 : "ImageWidth",
		0x0101 : "ImageHeight",
		0x8769 : "ExifIFDPointer",
		0x8825 : "GPSInfoIFDPointer",
		0xA005 : "InteroperabilityIFDPointer",
		0x0102 : "BitsPerSample",
		0x0103 : "Compression",
		0x0106 : "PhotometricInterpretation",
		0x0112 : "Orientation",
		0x0115 : "SamplesPerPixel",
		0x011C : "PlanarConfiguration",
		0x0212 : "YCbCrSubSampling",
		0x0213 : "YCbCrPositioning",
		0x011A : "XResolution",
		0x011B : "YResolution",
		0x0128 : "ResolutionUnit",
		0x0111 : "StripOffsets",
		0x0116 : "RowsPerStrip",
		0x0117 : "StripByteCounts",
		0x0201 : "JPEGInterchangeFormat",
		0x0202 : "JPEGInterchangeFormatLength",
		0x012D : "TransferFunction",
		0x013E : "WhitePoint",
		0x013F : "PrimaryChromaticities",
		0x0211 : "YCbCrCoefficients",
		0x0214 : "ReferenceBlackWhite",
		0x0132 : "DateTime",
		0x010E : "ImageDescription",
		0x010F : "Make",
		0x0110 : "Model",
		0x0131 : "Software",
		0x013B : "Artist",
		0x8298 : "Copyright"
	};

	var GPSTags = EXIF.GPSTags = {
		0x0000 : "GPSVersionID",
		0x0001 : "GPSLatitudeRef",
		0x0002 : "GPSLatitude",
		0x0003 : "GPSLongitudeRef",
		0x0004 : "GPSLongitude",
		0x0005 : "GPSAltitudeRef",
		0x0006 : "GPSAltitude",
		0x0007 : "GPSTimeStamp",
		0x0008 : "GPSSatellites",
		0x0009 : "GPSStatus",
		0x000A : "GPSMeasureMode",
		0x000B : "GPSDOP",
		0x000C : "GPSSpeedRef",
		0x000D : "GPSSpeed",
		0x000E : "GPSTrackRef",
		0x000F : "GPSTrack",
		0x0010 : "GPSImgDirectionRef",
		0x0011 : "GPSImgDirection",
		0x0012 : "GPSMapDatum",
		0x0013 : "GPSDestLatitudeRef",
		0x0014 : "GPSDestLatitude",
		0x0015 : "GPSDestLongitudeRef",
		0x0016 : "GPSDestLongitude",
		0x0017 : "GPSDestBearingRef",
		0x0018 : "GPSDestBearing",
		0x0019 : "GPSDestDistanceRef",
		0x001A : "GPSDestDistance",
		0x001B : "GPSProcessingMethod",
		0x001C : "GPSAreaInformation",
		0x001D : "GPSDateStamp",
		0x001E : "GPSDifferential"
	};

	// EXIF 2.3 Spec
	var IFD1Tags = EXIF.IFD1Tags = {
		0x0100: "ImageWidth",
		0x0101: "ImageHeight",
		0x0102: "BitsPerSample",
		0x0103: "Compression",
		0x0106: "PhotometricInterpretation",
		0x0111: "StripOffsets",
		0x0112: "Orientation",
		0x0115: "SamplesPerPixel",
		0x0116: "RowsPerStrip",
		0x0117: "StripByteCounts",
		0x011A: "XResolution",
		0x011B: "YResolution",
		0x011C: "PlanarConfiguration",
		0x0128: "ResolutionUnit",
		0x0201: "JpegIFOffset",    // When image format is JPEG, this value show offset to JPEG data stored.(aka "ThumbnailOffset" or "JPEGInterchangeFormat")
		0x0202: "JpegIFByteCount", // When image format is JPEG, this value shows data size of JPEG image (aka "ThumbnailLength" or "JPEGInterchangeFormatLength")
		0x0211: "YCbCrCoefficients",
		0x0212: "YCbCrSubSampling",
		0x0213: "YCbCrPositioning",
		0x0214: "ReferenceBlackWhite"
	};

	var StringValues = EXIF.StringValues = {
		ExposureProgram : {
			0 : "Not defined",
			1 : "Manual",
			2 : "Normal program",
			3 : "Aperture priority",
			4 : "Shutter priority",
			5 : "Creative program",
			6 : "Action program",
			7 : "Portrait mode",
			8 : "Landscape mode"
		},
		MeteringMode : {
			0 : "Unknown",
			1 : "Average",
			2 : "CenterWeightedAverage",
			3 : "Spot",
			4 : "MultiSpot",
			5 : "Pattern",
			6 : "Partial",
			255 : "Other"
		},
		LightSource : {
			0 : "Unknown",
			1 : "Daylight",
			2 : "Fluorescent",
			3 : "Tungsten (incandescent light)",
			4 : "Flash",
			9 : "Fine weather",
			10 : "Cloudy weather",
			11 : "Shade",
			12 : "Daylight fluorescent (D 5700 - 7100K)",
			13 : "Day white fluorescent (N 4600 - 5400K)",
			14 : "Cool white fluorescent (W 3900 - 4500K)",
			15 : "White fluorescent (WW 3200 - 3700K)",
			17 : "Standard light A",
			18 : "Standard light B",
			19 : "Standard light C",
			20 : "D55",
			21 : "D65",
			22 : "D75",
			23 : "D50",
			24 : "ISO studio tungsten",
			255 : "Other"
		},
		Flash : {
			0x0000 : "Flash did not fire",
			0x0001 : "Flash fired",
			0x0005 : "Strobe return light not detected",
			0x0007 : "Strobe return light detected",
			0x0009 : "Flash fired, compulsory flash mode",
			0x000D : "Flash fired, compulsory flash mode, return light not detected",
			0x000F : "Flash fired, compulsory flash mode, return light detected",
			0x0010 : "Flash did not fire, compulsory flash mode",
			0x0018 : "Flash did not fire, auto mode",
			0x0019 : "Flash fired, auto mode",
			0x001D : "Flash fired, auto mode, return light not detected",
			0x001F : "Flash fired, auto mode, return light detected",
			0x0020 : "No flash function",
			0x0041 : "Flash fired, red-eye reduction mode",
			0x0045 : "Flash fired, red-eye reduction mode, return light not detected",
			0x0047 : "Flash fired, red-eye reduction mode, return light detected",
			0x0049 : "Flash fired, compulsory flash mode, red-eye reduction mode",
			0x004D : "Flash fired, compulsory flash mode, red-eye reduction mode, return light not detected",
			0x004F : "Flash fired, compulsory flash mode, red-eye reduction mode, return light detected",
			0x0059 : "Flash fired, auto mode, red-eye reduction mode",
			0x005D : "Flash fired, auto mode, return light not detected, red-eye reduction mode",
			0x005F : "Flash fired, auto mode, return light detected, red-eye reduction mode"
		},
		SensingMethod : {
			1 : "Not defined",
			2 : "One-chip color area sensor",
			3 : "Two-chip color area sensor",
			4 : "Three-chip color area sensor",
			5 : "Color sequential area sensor",
			7 : "Trilinear sensor",
			8 : "Color sequential linear sensor"
		},
		SceneCaptureType : {
			0 : "Standard",
			1 : "Landscape",
			2 : "Portrait",
			3 : "Night scene"
		},
		SceneType : {
			1 : "Directly photographed"
		},
		CustomRendered : {
			0 : "Normal process",
			1 : "Custom process"
		},
		WhiteBalance : {
			0 : "Auto white balance",
			1 : "Manual white balance"
		},
		GainControl : {
			0 : "None",
			1 : "Low gain up",
			2 : "High gain up",
			3 : "Low gain down",
			4 : "High gain down"
		},
		Contrast : {
			0 : "Normal",
			1 : "Soft",
			2 : "Hard"
		},
		Saturation : {
			0 : "Normal",
			1 : "Low saturation",
			2 : "High saturation"
		},
		Sharpness : {
			0 : "Normal",
			1 : "Soft",
			2 : "Hard"
		},
		SubjectDistanceRange : {
			0 : "Unknown",
			1 : "Macro",
			2 : "Close view",
			3 : "Distant view"
		},
		FileSource : {
			3 : "DSC"
		},

		Components : {
			0 : "",
			1 : "Y",
			2 : "Cb",
			3 : "Cr",
			4 : "R",
			5 : "G",
			6 : "B"
		}
	};

	function addEvent(element, event, handler) {
		if (element.addEventListener) {
			element.addEventListener(event, handler, false);
		} else if (element.attachEvent) {
			element.attachEvent("on" + event, handler);
		}
	}

	function imageHasData(img) {
		return !!(img.exifdata);
	}


	function base64ToArrayBuffer(base64, contentType) {
		contentType = contentType || base64.match(/^data\:([^\;]+)\;base64,/mi)[1] || ''; // e.g. 'data:image/jpeg;base64,...' => 'image/jpeg'
		base64 = base64.replace(/^data\:([^\;]+)\;base64,/gmi, '');
		var binary = atob(base64);
		var len = binary.length;
		var buffer = new ArrayBuffer(len);
		var view = new Uint8Array(buffer);
		for (var i = 0; i < len; i++) {
			view[i] = binary.charCodeAt(i);
		}
		return buffer;
	}

	function objectURLToBlob(url, callback) {
		var http = new XMLHttpRequest();
		http.open("GET", url, true);
		http.responseType = "blob";
		http.onload = function(e) {
			if (this.status == 200 || this.status === 0) {
				callback(this.response);
			}
		};
		http.send();
	}

	function getImageData(img, callback) {
		function handleBinaryFile(binFile) {
			var data = findEXIFinJPEG(binFile);
			img.exifdata = data || {};
			var iptcdata = findIPTCinJPEG(binFile);
			img.iptcdata = iptcdata || {};
			if (EXIF.isXmpEnabled) {
				var xmpdata= findXMPinJPEG(binFile);
				img.xmpdata = xmpdata || {};
			}
			if (callback) {
				callback.call(img);
			}
		}

		if (img.src) {
			if (/^data\:/i.test(img.src)) { // Data URI
				var arrayBuffer = base64ToArrayBuffer(img.src);
				handleBinaryFile(arrayBuffer);

			} else if (/^blob\:/i.test(img.src)) { // Object URL
				var fileReader = new FileReader();
				fileReader.onload = function(e) {
					handleBinaryFile(e.target.result);
				};
				objectURLToBlob(img.src, function (blob) {
					fileReader.readAsArrayBuffer(blob);
				});
			} else {
				var http = new XMLHttpRequest();
				http.onload = function() {
					if (this.status == 200 || this.status === 0) {
						handleBinaryFile(http.response);
					} else {
						throw "Could not load image";
					}
					http = null;
				};
				http.open("GET", img.src, true);
				http.responseType = "arraybuffer";
				http.send(null);
			}
		} else if (self.FileReader && (img instanceof self.Blob || img instanceof self.File)) {
			var fileReader = new FileReader();
			fileReader.onload = function(e) {
				if (debug) console.log("Got file of length " + e.target.result.byteLength);
				handleBinaryFile(e.target.result);
			};

			fileReader.readAsArrayBuffer(img);
		}
	}

	function findEXIFinJPEG(file) {
		var dataView = new DataView(file);

		if (debug) console.log("Got file of length " + file.byteLength);
		if ((dataView.getUint8(0) != 0xFF) || (dataView.getUint8(1) != 0xD8)) {
			if (debug) console.log("Not a valid JPEG");
			return false; // not a valid jpeg
		}

		var offset = 2,
			length = file.byteLength,
			marker;

		while (offset < length) {
			if (dataView.getUint8(offset) != 0xFF) {
				if (debug) console.log("Not a valid marker at offset " + offset + ", found: " + dataView.getUint8(offset));
				return false; // not a valid marker, something is wrong
			}

			marker = dataView.getUint8(offset + 1);
			if (debug) console.log(marker);

			// we could implement handling for other markers here,
			// but we're only looking for 0xFFE1 for EXIF data

			if (marker == 225) {
				if (debug) console.log("Found 0xFFE1 marker");

				return readEXIFData(dataView, offset + 4, dataView.getUint16(offset + 2) - 2);

				// offset += 2 + file.getShortAt(offset+2, true);

			} else {
				offset += 2 + dataView.getUint16(offset+2);
			}

		}

	}

	function findIPTCinJPEG(file) {
		var dataView = new DataView(file);

		if (debug) console.log("Got file of length " + file.byteLength);
		if ((dataView.getUint8(0) != 0xFF) || (dataView.getUint8(1) != 0xD8)) {
			if (debug) console.log("Not a valid JPEG");
			return false; // not a valid jpeg
		}

		var offset = 2,
			length = file.byteLength;


		var isFieldSegmentStart = function(dataView, offset){
			return (
				dataView.getUint8(offset) === 0x38 &&
				dataView.getUint8(offset+1) === 0x42 &&
				dataView.getUint8(offset+2) === 0x49 &&
				dataView.getUint8(offset+3) === 0x4D &&
				dataView.getUint8(offset+4) === 0x04 &&
				dataView.getUint8(offset+5) === 0x04
			);
		};

		while (offset < length) {

			if ( isFieldSegmentStart(dataView, offset )){

				// Get the length of the name header (which is padded to an even number of bytes)
				var nameHeaderLength = dataView.getUint8(offset+7);
				if(nameHeaderLength % 2 !== 0) nameHeaderLength += 1;
				// Check for pre photoshop 6 format
				if(nameHeaderLength === 0) {
					// Always 4
					nameHeaderLength = 4;
				}

				var startOffset = offset + 8 + nameHeaderLength;
				var sectionLength = dataView.getUint16(offset + 6 + nameHeaderLength);

				return readIPTCData(file, startOffset, sectionLength);

				break;

			}


			// Not the marker, continue searching
			offset++;

		}

	}
	var IptcFieldMap = {
		0x78 : 'caption',
		0x6E : 'credit',
		0x19 : 'keywords',
		0x37 : 'dateCreated',
		0x50 : 'byline',
		0x55 : 'bylineTitle',
		0x7A : 'captionWriter',
		0x69 : 'headline',
		0x74 : 'copyright',
		0x0F : 'category'
	};
	function readIPTCData(file, startOffset, sectionLength){
		var dataView = new DataView(file);
		var data = {};
		var fieldValue, fieldName, dataSize, segmentType, segmentSize;
		var segmentStartPos = startOffset;
		while(segmentStartPos < startOffset+sectionLength) {
			if(dataView.getUint8(segmentStartPos) === 0x1C && dataView.getUint8(segmentStartPos+1) === 0x02){
				segmentType = dataView.getUint8(segmentStartPos+2);
				if(segmentType in IptcFieldMap) {
					dataSize = dataView.getInt16(segmentStartPos+3);
					segmentSize = dataSize + 5;
					fieldName = IptcFieldMap[segmentType];
					fieldValue = getStringFromDB(dataView, segmentStartPos+5, dataSize);
					// Check if we already stored a value with this name
					if(data.hasOwnProperty(fieldName)) {
						// Value already stored with this name, create multivalue field
						if(data[fieldName] instanceof Array) {
							data[fieldName].push(fieldValue);
						}
						else {
							data[fieldName] = [data[fieldName], fieldValue];
						}
					}
					else {
						data[fieldName] = fieldValue;
					}
				}

			}
			segmentStartPos++;
		}
		return data;
	}



	function readTags(file, tiffStart, dirStart, strings, bigEnd) {
		var entries = file.getUint16(dirStart, !bigEnd),
			tags = {},
			entryOffset, tag,
			i;

		for (i=0;i<entries;i++) {
			entryOffset = dirStart + i*12 + 2;
			tag = strings[file.getUint16(entryOffset, !bigEnd)];
			if (!tag && debug) console.log("Unknown tag: " + file.getUint16(entryOffset, !bigEnd));
			tags[tag] = readTagValue(file, entryOffset, tiffStart, dirStart, bigEnd);
		}
		return tags;
	}


	function readTagValue(file, entryOffset, tiffStart, dirStart, bigEnd) {
		var type = file.getUint16(entryOffset+2, !bigEnd),
			numValues = file.getUint32(entryOffset+4, !bigEnd),
			valueOffset = file.getUint32(entryOffset+8, !bigEnd) + tiffStart,
			offset,
			vals, val, n,
			numerator, denominator;

		switch (type) {
			case 1: // byte, 8-bit unsigned int
			case 7: // undefined, 8-bit byte, value depending on field
				if (numValues == 1) {
					return file.getUint8(entryOffset + 8, !bigEnd);
				} else {
					offset = numValues > 4 ? valueOffset : (entryOffset + 8);
					vals = [];
					for (n=0;n<numValues;n++) {
						vals[n] = file.getUint8(offset + n);
					}
					return vals;
				}

			case 2: // ascii, 8-bit byte
				offset = numValues > 4 ? valueOffset : (entryOffset + 8);
				return getStringFromDB(file, offset, numValues-1);

			case 3: // short, 16 bit int
				if (numValues == 1) {
					return file.getUint16(entryOffset + 8, !bigEnd);
				} else {
					offset = numValues > 2 ? valueOffset : (entryOffset + 8);
					vals = [];
					for (n=0;n<numValues;n++) {
						vals[n] = file.getUint16(offset + 2*n, !bigEnd);
					}
					return vals;
				}

			case 4: // long, 32 bit int
				if (numValues == 1) {
					return file.getUint32(entryOffset + 8, !bigEnd);
				} else {
					vals = [];
					for (n=0;n<numValues;n++) {
						vals[n] = file.getUint32(valueOffset + 4*n, !bigEnd);
					}
					return vals;
				}

			case 5:    // rational = two long values, first is numerator, second is denominator
				if (numValues == 1) {
					numerator = file.getUint32(valueOffset, !bigEnd);
					denominator = file.getUint32(valueOffset+4, !bigEnd);
					val = new Number(numerator / denominator);
					val.numerator = numerator;
					val.denominator = denominator;
					return val;
				} else {
					vals = [];
					for (n=0;n<numValues;n++) {
						numerator = file.getUint32(valueOffset + 8*n, !bigEnd);
						denominator = file.getUint32(valueOffset+4 + 8*n, !bigEnd);
						vals[n] = new Number(numerator / denominator);
						vals[n].numerator = numerator;
						vals[n].denominator = denominator;
					}
					return vals;
				}

			case 9: // slong, 32 bit signed int
				if (numValues == 1) {
					return file.getInt32(entryOffset + 8, !bigEnd);
				} else {
					vals = [];
					for (n=0;n<numValues;n++) {
						vals[n] = file.getInt32(valueOffset + 4*n, !bigEnd);
					}
					return vals;
				}

			case 10: // signed rational, two slongs, first is numerator, second is denominator
				if (numValues == 1) {
					return file.getInt32(valueOffset, !bigEnd) / file.getInt32(valueOffset+4, !bigEnd);
				} else {
					vals = [];
					for (n=0;n<numValues;n++) {
						vals[n] = file.getInt32(valueOffset + 8*n, !bigEnd) / file.getInt32(valueOffset+4 + 8*n, !bigEnd);
					}
					return vals;
				}
		}
	}

	/**
	 * Given an IFD (Image File Directory) start offset
	 * returns an offset to next IFD or 0 if it's the last IFD.
	 */
	function getNextIFDOffset(dataView, dirStart, bigEnd){
		//the first 2bytes means the number of directory entries contains in this IFD
		var entries = dataView.getUint16(dirStart, !bigEnd);

		// After last directory entry, there is a 4bytes of data,
		// it means an offset to next IFD.
		// If its value is '0x00000000', it means this is the last IFD and there is no linked IFD.

		return dataView.getUint32(dirStart + 2 + entries * 12, !bigEnd); // each entry is 12 bytes long
	}

	function readThumbnailImage(dataView, tiffStart, firstIFDOffset, bigEnd){
		// get the IFD1 offset
		var IFD1OffsetPointer = getNextIFDOffset(dataView, tiffStart+firstIFDOffset, bigEnd);

		if (!IFD1OffsetPointer) {
			// console.log('******** IFD1Offset is empty, image thumb not found ********');
			return {};
		}
		else if (IFD1OffsetPointer > dataView.byteLength) { // this should not happen
			// console.log('******** IFD1Offset is outside the bounds of the DataView ********');
			return {};
		}
		// console.log('*******  thumbnail IFD offset (IFD1) is: %s', IFD1OffsetPointer);

		var thumbTags = readTags(dataView, tiffStart, tiffStart + IFD1OffsetPointer, IFD1Tags, bigEnd)

		// EXIF 2.3 specification for JPEG format thumbnail

		// If the value of Compression(0x0103) Tag in IFD1 is '6', thumbnail image format is JPEG.
		// Most of Exif image uses JPEG format for thumbnail. In that case, you can get offset of thumbnail
		// by JpegIFOffset(0x0201) Tag in IFD1, size of thumbnail by JpegIFByteCount(0x0202) Tag.
		// Data format is ordinary JPEG format, starts from 0xFFD8 and ends by 0xFFD9. It seems that
		// JPEG format and 160x120pixels of size are recommended thumbnail format for Exif2.1 or later.

		if (thumbTags['Compression']) {
			// console.log('Thumbnail image found!');

			switch (thumbTags['Compression']) {
				case 6:
					// console.log('Thumbnail image format is JPEG');
					if (thumbTags.JpegIFOffset && thumbTags.JpegIFByteCount) {
						// extract the thumbnail
						var tOffset = tiffStart + thumbTags.JpegIFOffset;
						var tLength = thumbTags.JpegIFByteCount;
						thumbTags['blob'] = new Blob([new Uint8Array(dataView.buffer, tOffset, tLength)], {
							type: 'image/jpeg'
						});
					}
					break;

				case 1:
					console.log("Thumbnail image format is TIFF, which is not implemented.");
					break;
				default:
					console.log("Unknown thumbnail image format '%s'", thumbTags['Compression']);
			}
		}
		else if (thumbTags['PhotometricInterpretation'] == 2) {
			console.log("Thumbnail image format is RGB, which is not implemented.");
		}
		return thumbTags;
	}

	function getStringFromDB(buffer, start, length) {
		var outstr = "";
		for (var n = start; n < start+length; n++) {
			outstr += String.fromCharCode(buffer.getUint8(n));
		}
		return outstr;
	}

	function readEXIFData(file, start) {
		if (getStringFromDB(file, start, 4) != "Exif") {
			if (debug) console.log("Not valid EXIF data! " + getStringFromDB(file, start, 4));
			return false;
		}

		var bigEnd,
			tags, tag,
			exifData, gpsData,
			tiffOffset = start + 6;

		// test for TIFF validity and endianness
		if (file.getUint16(tiffOffset) == 0x4949) {
			bigEnd = false;
		} else if (file.getUint16(tiffOffset) == 0x4D4D) {
			bigEnd = true;
		} else {
			if (debug) console.log("Not valid TIFF data! (no 0x4949 or 0x4D4D)");
			return false;
		}

		if (file.getUint16(tiffOffset+2, !bigEnd) != 0x002A) {
			if (debug) console.log("Not valid TIFF data! (no 0x002A)");
			return false;
		}

		var firstIFDOffset = file.getUint32(tiffOffset+4, !bigEnd);

		if (firstIFDOffset < 0x00000008) {
			if (debug) console.log("Not valid TIFF data! (First offset less than 8)", file.getUint32(tiffOffset+4, !bigEnd));
			return false;
		}

		tags = readTags(file, tiffOffset, tiffOffset + firstIFDOffset, TiffTags, bigEnd);

		if (tags.ExifIFDPointer) {
			exifData = readTags(file, tiffOffset, tiffOffset + tags.ExifIFDPointer, ExifTags, bigEnd);
			for (tag in exifData) {
				switch (tag) {
					case "LightSource" :
					case "Flash" :
					case "MeteringMode" :
					case "ExposureProgram" :
					case "SensingMethod" :
					case "SceneCaptureType" :
					case "SceneType" :
					case "CustomRendered" :
					case "WhiteBalance" :
					case "GainControl" :
					case "Contrast" :
					case "Saturation" :
					case "Sharpness" :
					case "SubjectDistanceRange" :
					case "FileSource" :
						exifData[tag] = StringValues[tag][exifData[tag]];
						break;

					case "ExifVersion" :
					case "FlashpixVersion" :
						exifData[tag] = String.fromCharCode(exifData[tag][0], exifData[tag][1], exifData[tag][2], exifData[tag][3]);
						break;

					case "ComponentsConfiguration" :
						exifData[tag] =
							StringValues.Components[exifData[tag][0]] +
							StringValues.Components[exifData[tag][1]] +
							StringValues.Components[exifData[tag][2]] +
							StringValues.Components[exifData[tag][3]];
						break;
				}
				tags[tag] = exifData[tag];
			}
		}

		if (tags.GPSInfoIFDPointer) {
			gpsData = readTags(file, tiffOffset, tiffOffset + tags.GPSInfoIFDPointer, GPSTags, bigEnd);
			for (tag in gpsData) {
				switch (tag) {
					case "GPSVersionID" :
						gpsData[tag] = gpsData[tag][0] +
							"." + gpsData[tag][1] +
							"." + gpsData[tag][2] +
							"." + gpsData[tag][3];
						break;
				}
				tags[tag] = gpsData[tag];
			}
		}

		// extract thumbnail
		tags['thumbnail'] = readThumbnailImage(file, tiffOffset, firstIFDOffset, bigEnd);

		return tags;
	}

	function findXMPinJPEG(file) {

		if (!('DOMParser' in self)) {
			// console.warn('XML parsing not supported without DOMParser');
			return;
		}
		var dataView = new DataView(file);

		if (debug) console.log("Got file of length " + file.byteLength);
		if ((dataView.getUint8(0) != 0xFF) || (dataView.getUint8(1) != 0xD8)) {
			if (debug) console.log("Not a valid JPEG");
			return false; // not a valid jpeg
		}

		var offset = 2,
			length = file.byteLength,
			dom = new DOMParser();

		while (offset < (length-4)) {
			if (getStringFromDB(dataView, offset, 4) == "http") {
				var startOffset = offset - 1;
				var sectionLength = dataView.getUint16(offset - 2) - 1;
				var xmpString = getStringFromDB(dataView, startOffset, sectionLength)
				var xmpEndIndex = xmpString.indexOf('xmpmeta>') + 8;
				xmpString = xmpString.substring( xmpString.indexOf( '<x:xmpmeta' ), xmpEndIndex );

				var indexOfXmp = xmpString.indexOf('x:xmpmeta') + 10
				//Many custom written programs embed xmp/xml without any namespace. Following are some of them.
				//Without these namespaces, XML is thought to be invalid by parsers
				xmpString = xmpString.slice(0, indexOfXmp)
					+ 'xmlns:Iptc4xmpCore="http://iptc.org/std/Iptc4xmpCore/1.0/xmlns/" '
					+ 'xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" '
					+ 'xmlns:tiff="http://ns.adobe.com/tiff/1.0/" '
					+ 'xmlns:plus="http://schemas.android.com/apk/lib/com.google.android.gms.plus" '
					+ 'xmlns:ext="http://www.gettyimages.com/xsltExtension/1.0" '
					+ 'xmlns:exif="http://ns.adobe.com/exif/1.0/" '
					+ 'xmlns:stEvt="http://ns.adobe.com/xap/1.0/sType/ResourceEvent#" '
					+ 'xmlns:stRef="http://ns.adobe.com/xap/1.0/sType/ResourceRef#" '
					+ 'xmlns:crs="http://ns.adobe.com/camera-raw-settings/1.0/" '
					+ 'xmlns:xapGImg="http://ns.adobe.com/xap/1.0/g/img/" '
					+ 'xmlns:Iptc4xmpExt="http://iptc.org/std/Iptc4xmpExt/2008-02-29/" '
					+ xmpString.slice(indexOfXmp)

				var domDocument = dom.parseFromString( xmpString, 'text/xml' );
				return xml2Object(domDocument);
			} else{
				offset++;
			}
		}
	}

	function xml2json(xml) {
		var json = {};

		if (xml.nodeType == 1) { // element node
			if (xml.attributes.length > 0) {
				json['@attributes'] = {};
				for (var j = 0; j < xml.attributes.length; j++) {
					var attribute = xml.attributes.item(j);
					json['@attributes'][attribute.nodeName] = attribute.nodeValue;
				}
			}
		} else if (xml.nodeType == 3) { // text node
			return xml.nodeValue;
		}

		// deal with children
		if (xml.hasChildNodes()) {
			for(var i = 0; i < xml.childNodes.length; i++) {
				var child = xml.childNodes.item(i);
				var nodeName = child.nodeName;
				if (json[nodeName] == null) {
					json[nodeName] = xml2json(child);
				} else {
					if (json[nodeName].push == null) {
						var old = json[nodeName];
						json[nodeName] = [];
						json[nodeName].push(old);
					}
					json[nodeName].push(xml2json(child));
				}
			}
		}

		return json;
	}

	function xml2Object(xml) {
		try {
			var obj = {};
			if (xml.children.length > 0) {
				for (var i = 0; i < xml.children.length; i++) {
					var item = xml.children.item(i);
					var attributes = item.attributes;
					for(var idx in attributes) {
						var itemAtt = attributes[idx];
						var dataKey = itemAtt.nodeName;
						var dataValue = itemAtt.nodeValue;

						if(dataKey !== undefined) {
							obj[dataKey] = dataValue;
						}
					}
					var nodeName = item.nodeName;

					if (typeof (obj[nodeName]) == "undefined") {
						obj[nodeName] = xml2json(item);
					} else {
						if (typeof (obj[nodeName].push) == "undefined") {
							var old = obj[nodeName];

							obj[nodeName] = [];
							obj[nodeName].push(old);
						}
						obj[nodeName].push(xml2json(item));
					}
				}
			} else {
				obj = xml.textContent;
			}
			return obj;
		} catch (e) {
			console.log(e.message);
		}
	}

	EXIF.enableXmp = function() {
		EXIF.isXmpEnabled = true;
	}

	EXIF.disableXmp = function() {
		EXIF.isXmpEnabled = false;
	}

	EXIF.getData = function(img, callback) {
		if (((self.Image && img instanceof self.Image)
			|| (self.HTMLImageElement && img instanceof self.HTMLImageElement))
			&& !img.complete)
			return false;

		if (!imageHasData(img)) {
			getImageData(img, callback);
		} else {
			if (callback) {
				callback.call(img);
			}
		}
		return true;
	}

	EXIF.getTag = function(img, tag) {
		if (!imageHasData(img)) return;
		return img.exifdata[tag];
	}

	EXIF.getIptcTag = function(img, tag) {
		if (!imageHasData(img)) return;
		return img.iptcdata[tag];
	}

	EXIF.getAllTags = function(img) {
		if (!imageHasData(img)) return {};
		var a,
			data = img.exifdata,
			tags = {};
		for (a in data) {
			if (data.hasOwnProperty(a)) {
				tags[a] = data[a];
			}
		}
		return tags;
	}

	EXIF.getAllIptcTags = function(img) {
		if (!imageHasData(img)) return {};
		var a,
			data = img.iptcdata,
			tags = {};
		for (a in data) {
			if (data.hasOwnProperty(a)) {
				tags[a] = data[a];
			}
		}
		return tags;
	}

	EXIF.pretty = function(img) {
		if (!imageHasData(img)) return "";
		var a,
			data = img.exifdata,
			strPretty = "";
		for (a in data) {
			if (data.hasOwnProperty(a)) {
				if (typeof data[a] == "object") {
					if (data[a] instanceof Number) {
						strPretty += a + " : " + data[a] + " [" + data[a].numerator + "/" + data[a].denominator + "]\r\n";
					} else {
						strPretty += a + " : [" + data[a].length + " values]\r\n";
					}
				} else {
					strPretty += a + " : " + data[a] + "\r\n";
				}
			}
		}
		return strPretty;
	}

	EXIF.readFromBinaryFile = function(file) {
		return findEXIFinJPEG(file);
	}

	if (typeof define === 'function' && define.amd) {
		define('exif-js', [], function() {
			return EXIF;
		});
	}
}.call(this));
