/* piexifjs

The MIT License (MIT)

Copyright (c) 2014, 2015 hMatoba(https://github.com/hMatoba)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

(function () {
    "use strict";
    var that = {};
    that.version = "1.03";

    that.remove = function (jpeg) {
        var b64 = false;
        if (jpeg.slice(0, 2) == "\xff\xd8") {
        } else if (jpeg.slice(0, 23) == "data:image/jpeg;base64," || jpeg.slice(0, 22) == "data:image/jpg;base64,") {
            jpeg = atob(jpeg.split(",")[1]);
            b64 = true;
        } else {
            throw ("Given data is not jpeg.");
        }
        
        var segments = splitIntoSegments(jpeg);
        if (segments[1].slice(0, 2) == "\xff\xe1" && 
               segments[1].slice(4, 10) == "Exif\x00\x00") {
            segments = [segments[0]].concat(segments.slice(2));
        } else if (segments[2].slice(0, 2) == "\xff\xe1" &&
                   segments[2].slice(4, 10) == "Exif\x00\x00") {
            segments = segments.slice(0, 2).concat(segments.slice(3));
        } else {
            throw("Exif not found.");
        }
        
        var new_data = segments.join("");
        if (b64) {
            new_data = "data:image/jpeg;base64," + btoa(new_data);
        }

        return new_data;
    };


    that.insert = function (exif, jpeg) {
        var b64 = false;
        if (exif.slice(0, 6) != "\x45\x78\x69\x66\x00\x00") {
            throw ("Given data is not exif.");
        }
        if (jpeg.slice(0, 2) == "\xff\xd8") {
        } else if (jpeg.slice(0, 23) == "data:image/jpeg;base64," || jpeg.slice(0, 22) == "data:image/jpg;base64,") {
            jpeg = atob(jpeg.split(",")[1]);
            b64 = true;
        } else {
            throw ("Given data is not jpeg.");
        }

        var exifStr = "\xff\xe1" + pack(">H", [exif.length + 2]) + exif;
        var segments = splitIntoSegments(jpeg);
        var new_data = mergeSegments(segments, exifStr);
        if (b64) {
            new_data = "data:image/jpeg;base64," + btoa(new_data);
        }

        return new_data;
    };


    that.load = function (data) {
        var input_data;
        if (typeof (data) == "string") {
            if (data.slice(0, 2) == "\xff\xd8") {
                input_data = data;
            } else if (data.slice(0, 23) == "data:image/jpeg;base64," || data.slice(0, 22) == "data:image/jpg;base64,") {
                input_data = atob(data.split(",")[1]);
            } else if (data.slice(0, 4) == "Exif") {
                input_data = data.slice(6);
            } else {
                throw ("'load' gots invalid file data.");
            }
        } else {
            throw ("'load' gots invalid type argument.");
        }

        var exifDict = {};
        var exif_dict = {
            "0th": {},
            "Exif": {},
            "GPS": {},
            "Interop": {},
            "1st": {},
            "thumbnail": null
        };
        var exifReader = new ExifReader(input_data);
        if (exifReader.tiftag === null) {
            return exif_dict;
        }

        if (exifReader.tiftag.slice(0, 2) == "\x49\x49") {
            exifReader.endian_mark = "<";
        } else {
            exifReader.endian_mark = ">";
        }

        var pointer = unpack(exifReader.endian_mark + "L",
            exifReader.tiftag.slice(4, 8))[0];
        exif_dict["0th"] = exifReader.get_ifd(pointer, "0th");

        var first_ifd_pointer = exif_dict["0th"]["first_ifd_pointer"];
        delete exif_dict["0th"]["first_ifd_pointer"];

        if (34665 in exif_dict["0th"]) {
            pointer = exif_dict["0th"][34665];
            exif_dict["Exif"] = exifReader.get_ifd(pointer, "Exif");
        }
        if (34853 in exif_dict["0th"]) {
            pointer = exif_dict["0th"][34853];
            exif_dict["GPS"] = exifReader.get_ifd(pointer, "GPS");
        }
        if (40965 in exif_dict["Exif"]) {
            pointer = exif_dict["Exif"][40965];
            exif_dict["Interop"] = exifReader.get_ifd(pointer, "Interop");
        }
        if (first_ifd_pointer != "\x00\x00\x00\x00") {
            pointer = unpack(exifReader.endian_mark + "L",
                first_ifd_pointer)[0];
            exif_dict["1st"] = exifReader.get_ifd(pointer, "1st");
            if ((513 in exif_dict["1st"]) && (514 in exif_dict["1st"])) {
                var end = exif_dict["1st"][513] + exif_dict["1st"][514];
                var thumb = exifReader.tiftag.slice(exif_dict["1st"][513], end);
                exif_dict["thumbnail"] = thumb;
            }
        }

        return exif_dict;
    };


    that.dump = function (exif_dict_original) {
        var TIFF_HEADER_LENGTH = 8;

        var exif_dict = copy(exif_dict_original);
        var header = "Exif\x00\x00\x4d\x4d\x00\x2a\x00\x00\x00\x08";
        var exif_is = false;
        var gps_is = false;
        var interop_is = false;
        var first_is = false;

        var zeroth_ifd,
            exif_ifd,
            interop_ifd,
            gps_ifd,
            first_ifd;
        
        if ("0th" in exif_dict) {
            zeroth_ifd = exif_dict["0th"];
        } else {
            zeroth_ifd = {};
        }
        
        if ((("Exif" in exif_dict) && (Object.keys(exif_dict["Exif"]).length)) ||
            (("Interop" in exif_dict) && (Object.keys(exif_dict["Interop"]).length))) {
            zeroth_ifd[34665] = 1;
            exif_is = true;
            exif_ifd = exif_dict["Exif"];
            if (("Interop" in exif_dict) && Object.keys(exif_dict["Interop"]).length) {
                exif_ifd[40965] = 1;
                interop_is = true;
                interop_ifd = exif_dict["Interop"];
            } else if (Object.keys(exif_ifd).indexOf(that.ExifIFD.InteroperabilityTag.toString()) > -1) {
                delete exif_ifd[40965];
            }
        } else if (Object.keys(zeroth_ifd).indexOf(that.ImageIFD.ExifTag.toString()) > -1) {
            delete zeroth_ifd[34665];
        }

        if (("GPS" in exif_dict) && (Object.keys(exif_dict["GPS"]).length)) {
            zeroth_ifd[that.ImageIFD.GPSTag] = 1;
            gps_is = true;
            gps_ifd = exif_dict["GPS"];
        } else if (Object.keys(zeroth_ifd).indexOf(that.ImageIFD.GPSTag.toString()) > -1) {
            delete zeroth_ifd[that.ImageIFD.GPSTag];
        }
        
        if (("1st" in exif_dict) &&
            ("thumbnail" in exif_dict) &&
            (exif_dict["thumbnail"] != null)) {
            first_is = true;
            exif_dict["1st"][513] = 1;
            exif_dict["1st"][514] = 1;
            first_ifd = exif_dict["1st"];
        }
        
        var zeroth_set = _dict_to_bytes(zeroth_ifd, "0th", 0);
        var zeroth_length = (zeroth_set[0].length + exif_is * 12 + gps_is * 12 + 4 +
            zeroth_set[1].length);

        var exif_set,
            exif_bytes = "",
            exif_length = 0,
            gps_set,
            gps_bytes = "",
            gps_length = 0,
            interop_set,
            interop_bytes = "",
            interop_length = 0,
            first_set,
            first_bytes = "",
            thumbnail;
        if (exif_is) {
            exif_set = _dict_to_bytes(exif_ifd, "Exif", zeroth_length);
            exif_length = exif_set[0].length + interop_is * 12 + exif_set[1].length;
        }
        if (gps_is) {
            gps_set = _dict_to_bytes(gps_ifd, "GPS", zeroth_length + exif_length);
            gps_bytes = gps_set.join("");
            gps_length = gps_bytes.length;
        }
        if (interop_is) {
            var offset = zeroth_length + exif_length + gps_length;
            interop_set = _dict_to_bytes(interop_ifd, "Interop", offset);
            interop_bytes = interop_set.join("");
            interop_length = interop_bytes.length;
        }
        if (first_is) {
            var offset = zeroth_length + exif_length + gps_length + interop_length;
            first_set = _dict_to_bytes(first_ifd, "1st", offset);
            thumbnail = _get_thumbnail(exif_dict["thumbnail"]);
            if (thumbnail.length > 64000) {
                throw ("Given thumbnail is too large. max 64kB");
            }
        }

        var exif_pointer = "",
            gps_pointer = "",
            interop_pointer = "",
            first_ifd_pointer = "\x00\x00\x00\x00";
        if (exif_is) {
            var pointer_value = TIFF_HEADER_LENGTH + zeroth_length;
            var pointer_str = pack(">L", [pointer_value]);
            var key = 34665;
            var key_str = pack(">H", [key]);
            var type_str = pack(">H", [TYPES["Long"]]);
            var length_str = pack(">L", [1]);
            exif_pointer = key_str + type_str + length_str + pointer_str;
        }
        if (gps_is) {
            var pointer_value = TIFF_HEADER_LENGTH + zeroth_length + exif_length;
            var pointer_str = pack(">L", [pointer_value]);
            var key = 34853;
            var key_str = pack(">H", [key]);
            var type_str = pack(">H", [TYPES["Long"]]);
            var length_str = pack(">L", [1]);
            gps_pointer = key_str + type_str + length_str + pointer_str;
        }
        if (interop_is) {
            var pointer_value = (TIFF_HEADER_LENGTH +
                zeroth_length + exif_length + gps_length);
            var pointer_str = pack(">L", [pointer_value]);
            var key = 40965;
            var key_str = pack(">H", [key]);
            var type_str = pack(">H", [TYPES["Long"]]);
            var length_str = pack(">L", [1]);
            interop_pointer = key_str + type_str + length_str + pointer_str;
        }
        if (first_is) {
            var pointer_value = (TIFF_HEADER_LENGTH + zeroth_length +
                exif_length + gps_length + interop_length);
            first_ifd_pointer = pack(">L", [pointer_value]);
            var thumbnail_pointer = (pointer_value + first_set[0].length + 24 +
                4 + first_set[1].length);
            var thumbnail_p_bytes = ("\x02\x01\x00\x04\x00\x00\x00\x01" +
                pack(">L", [thumbnail_pointer]));
            var thumbnail_length_bytes = ("\x02\x02\x00\x04\x00\x00\x00\x01" +
                pack(">L", [thumbnail.length]));
            first_bytes = (first_set[0] + thumbnail_p_bytes +
                thumbnail_length_bytes + "\x00\x00\x00\x00" +
                first_set[1] + thumbnail);
        }

        var zeroth_bytes = (zeroth_set[0] + exif_pointer + gps_pointer +
            first_ifd_pointer + zeroth_set[1]);
        if (exif_is) {
            exif_bytes = exif_set[0] + interop_pointer + exif_set[1];
        }

        return (header + zeroth_bytes + exif_bytes + gps_bytes +
            interop_bytes + first_bytes);
    };


    function copy(obj) {
        return JSON.parse(JSON.stringify(obj));
    }


    function _get_thumbnail(jpeg) {
        var segments = splitIntoSegments(jpeg);
        while (("\xff\xe0" <= segments[1].slice(0, 2)) && (segments[1].slice(0, 2) <= "\xff\xef")) {
            segments = [segments[0]].concat(segments.slice(2));
        }
        return segments.join("");
    }


    function _pack_byte(array) {
        return pack(">" + nStr("B", array.length), array);
    }


    function _pack_short(array) {
        return pack(">" + nStr("H", array.length), array);
    }


    function _pack_long(array) {
        return pack(">" + nStr("L", array.length), array);
    }


    function _value_to_bytes(raw_value, value_type, offset) {
        var four_bytes_over = "";
        var value_str = "";
        var length,
            new_value,
            num,
            den;

        if (value_type == "Byte") {
            length = raw_value.length;
            if (length <= 4) {
                value_str = (_pack_byte(raw_value) +
                    nStr("\x00", 4 - length));
            } else {
                value_str = pack(">L", [offset]);
                four_bytes_over = _pack_byte(raw_value);
            }
        } else if (value_type == "Short") {
            length = raw_value.length;
            if (length <= 2) {
                value_str = (_pack_short(raw_value) +
                    nStr("\x00\x00", 2 - length));
            } else {
                value_str = pack(">L", [offset]);
                four_bytes_over = _pack_short(raw_value);
            }
        } else if (value_type == "Long") {
            length = raw_value.length;
            if (length <= 1) {
                value_str = _pack_long(raw_value);
            } else {
                value_str = pack(">L", [offset]);
                four_bytes_over = _pack_long(raw_value);
            }
        } else if (value_type == "Ascii") {
            new_value = raw_value + "\x00";
            length = new_value.length;
            if (length > 4) {
                value_str = pack(">L", [offset]);
                four_bytes_over = new_value;
            } else {
                value_str = new_value + nStr("\x00", 4 - length);
            }
        } else if (value_type == "Rational") {
            if (typeof (raw_value[0]) == "number") {
                length = 1;
                num = raw_value[0];
                den = raw_value[1];
                new_value = pack(">L", [num]) + pack(">L", [den]);
            } else {
                length = raw_value.length;
                new_value = "";
                for (var n = 0; n < length; n++) {
                    num = raw_value[n][0];
                    den = raw_value[n][1];
                    new_value += (pack(">L", [num]) +
                        pack(">L", [den]));
                }
            }
            value_str = pack(">L", [offset]);
            four_bytes_over = new_value;
        } else if (value_type == "SRational") {
            if (typeof (raw_value[0]) == "number") {
                length = 1;
                num = raw_value[0];
                den = raw_value[1];
                new_value = pack(">l", [num]) + pack(">l", [den]);
            } else {
                length = raw_value.length;
                new_value = "";
                for (var n = 0; n < length; n++) {
                    num = raw_value[n][0];
                    den = raw_value[n][1];
                    new_value += (pack(">l", [num]) +
                        pack(">l", [den]));
                }
            }
            value_str = pack(">L", [offset]);
            four_bytes_over = new_value;
        } else if (value_type == "Undefined") {
            length = raw_value.length;
            if (length > 4) {
                value_str = pack(">L", [offset]);
                four_bytes_over = raw_value;
            } else {
                value_str = raw_value + nStr("\x00", 4 - length);
            }
        }

        var length_str = pack(">L", [length]);

        return [length_str, value_str, four_bytes_over];
    }

    function _dict_to_bytes(ifd_dict, ifd, ifd_offset) {
        var TIFF_HEADER_LENGTH = 8;
        var tag_count = Object.keys(ifd_dict).length;
        var entry_header = pack(">H", [tag_count]);
        var entries_length;
        if (["0th", "1st"].indexOf(ifd) > -1) {
            entries_length = 2 + tag_count * 12 + 4;
        } else {
            entries_length = 2 + tag_count * 12;
        }
        var entries = "";
        var values = "";
        var key;

        for (var key in ifd_dict) {
            if (typeof (key) == "string") {
                key = parseInt(key);
            }
            if ((ifd == "0th") && ([34665, 34853].indexOf(key) > -1)) {
                continue;
            } else if ((ifd == "Exif") && (key == 40965)) {
                continue;
            } else if ((ifd == "1st") && ([513, 514].indexOf(key) > -1)) {
                continue;
            }

            var raw_value = ifd_dict[key];
            var key_str = pack(">H", [key]);
            var value_type = TAGS[ifd][key]["type"];
            var type_str = pack(">H", [TYPES[value_type]]);

            if (typeof (raw_value) == "number") {
                raw_value = [raw_value];
            }
            var offset = TIFF_HEADER_LENGTH + entries_length + ifd_offset + values.length;
            var b = _value_to_bytes(raw_value, value_type, offset);
            var length_str = b[0];
            var value_str = b[1];
            var four_bytes_over = b[2];

            entries += key_str + type_str + length_str + value_str;
            values += four_bytes_over;
        }

        return [entry_header + entries, values];
    }



    function ExifReader(data) {
        var segments,
            app1;
        if (data.slice(0, 2) == "\xff\xd8") { // JPEG
            segments = splitIntoSegments(data);
            app1 = getExifSeg(segments);
            if (app1) {
                this.tiftag = app1.slice(10);
            } else {
                this.tiftag = null;
            }
        } else if (["\x49\x49", "\x4d\x4d"].indexOf(data.slice(0, 2)) > -1) { // TIFF
            this.tiftag = data;
        } else if (data.slice(0, 4) == "Exif") { // Exif
            this.tiftag = data.slice(6);
        } else {
            throw ("Given file is neither JPEG nor TIFF.");
        }
    }

    ExifReader.prototype = {
        get_ifd: function (pointer, ifd_name) {
            var ifd_dict = {};
            var tag_count = unpack(this.endian_mark + "H",
                this.tiftag.slice(pointer, pointer + 2))[0];
            var offset = pointer + 2;
            var t;
            if (["0th", "1st"].indexOf(ifd_name) > -1) {
                t = "Image";
            } else {
                t = ifd_name;
            }

            for (var x = 0; x < tag_count; x++) {
                pointer = offset + 12 * x;
                var tag = unpack(this.endian_mark + "H",
                    this.tiftag.slice(pointer, pointer + 2))[0];
                var value_type = unpack(this.endian_mark + "H",
                    this.tiftag.slice(pointer + 2, pointer + 4))[0];
                var value_num = unpack(this.endian_mark + "L",
                    this.tiftag.slice(pointer + 4, pointer + 8))[0];
                var value = this.tiftag.slice(pointer + 8, pointer + 12);

                var v_set = [value_type, value_num, value];
                if (tag in TAGS[t]) {
                    ifd_dict[tag] = this.convert_value(v_set);
                }
            }

            if (ifd_name == "0th") {
                pointer = offset + 12 * tag_count;
                ifd_dict["first_ifd_pointer"] = this.tiftag.slice(pointer, pointer + 4);
            }

            return ifd_dict;
        },

        convert_value: function (val) {
            var data = null;
            var t = val[0];
            var length = val[1];
            var value = val[2];
            var pointer;

            if (t == 1) { // BYTE
                if (length > 4) {
                    pointer = unpack(this.endian_mark + "L", value)[0];
                    data = unpack(this.endian_mark + nStr("B", length),
                        this.tiftag.slice(pointer, pointer + length));
                } else {
                    data = unpack(this.endian_mark + nStr("B", length), value.slice(0, length));
                }
            } else if (t == 2) { // ASCII
                if (length > 4) {
                    pointer = unpack(this.endian_mark + "L", value)[0];
                    data = this.tiftag.slice(pointer, pointer + length - 1);
                } else {
                    data = value.slice(0, length - 1);
                }
            } else if (t == 3) { // SHORT
                if (length > 2) {
                    pointer = unpack(this.endian_mark + "L", value)[0];
                    data = unpack(this.endian_mark + nStr("H", length),
                        this.tiftag.slice(pointer, pointer + length * 2));
                } else {
                    data = unpack(this.endian_mark + nStr("H", length),
                        value.slice(0, length * 2));
                }
            } else if (t == 4) { // LONG
                if (length > 1) {
                    pointer = unpack(this.endian_mark + "L", value)[0];
                    data = unpack(this.endian_mark + nStr("L", length),
                        this.tiftag.slice(pointer, pointer + length * 4));
                } else {
                    data = unpack(this.endian_mark + nStr("L", length),
                        value);
                }
            } else if (t == 5) { // RATIONAL
                pointer = unpack(this.endian_mark + "L", value)[0];
                if (length > 1) {
                    data = [];
                    for (var x = 0; x < length; x++) {
                        data.push([unpack(this.endian_mark + "L",
                                this.tiftag.slice(pointer + x * 8, pointer + 4 + x * 8))[0],
                                   unpack(this.endian_mark + "L",
                                this.tiftag.slice(pointer + 4 + x * 8, pointer + 8 + x * 8))[0]
                                   ]);
                    }
                } else {
                    data = [unpack(this.endian_mark + "L",
                            this.tiftag.slice(pointer, pointer + 4))[0],
                            unpack(this.endian_mark + "L",
                            this.tiftag.slice(pointer + 4, pointer + 8))[0]
                            ];
                }
            } else if (t == 7) { // UNDEFINED BYTES
                if (length > 4) {
                    pointer = unpack(this.endian_mark + "L", value)[0];
                    data = this.tiftag.slice(pointer, pointer + length);
                } else {
                    data = value.slice(0, length);
                }
            } else if (t == 10) { // SRATIONAL
                pointer = unpack(this.endian_mark + "L", value)[0];
                if (length > 1) {
                    data = [];
                    for (var x = 0; x < length; x++) {
                        data.push([unpack(this.endian_mark + "l",
                                this.tiftag.slice(pointer + x * 8, pointer + 4 + x * 8))[0],
                                   unpack(this.endian_mark + "l",
                                this.tiftag.slice(pointer + 4 + x * 8, pointer + 8 + x * 8))[0]
                                  ]);
                    }
                } else {
                    data = [unpack(this.endian_mark + "l",
                            this.tiftag.slice(pointer, pointer + 4))[0],
                            unpack(this.endian_mark + "l",
                            this.tiftag.slice(pointer + 4, pointer + 8))[0]
                           ];
                }
            } else {
                throw ("Exif might be wrong. Got incorrect value " +
                    "type to decode. type:" + t);
            }

            if ((data instanceof Array) && (data.length == 1)) {
                return data[0];
            } else {
                return data;
            }
        },
    };


    if (typeof window !== "undefined" && typeof window.btoa === "function") {
        var btoa = window.btoa;
    }
    if (typeof btoa === "undefined") {
        var btoa = function (input) {        var output = "";
            var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
            var i = 0;
            var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

            while (i < input.length) {

                chr1 = input.charCodeAt(i++);
                chr2 = input.charCodeAt(i++);
                chr3 = input.charCodeAt(i++);

                enc1 = chr1 >> 2;
                enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
                enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
                enc4 = chr3 & 63;

                if (isNaN(chr2)) {
                    enc3 = enc4 = 64;
                } else if (isNaN(chr3)) {
                    enc4 = 64;
                }

                output = output +
                keyStr.charAt(enc1) + keyStr.charAt(enc2) +
                keyStr.charAt(enc3) + keyStr.charAt(enc4);

            }

            return output;
        };
    }
    
    
    if (typeof window !== "undefined" && typeof window.atob === "function") {
        var atob = window.atob;
    }
    if (typeof atob === "undefined") {
        var atob = function (input) {
            var output = "";
            var chr1, chr2, chr3;
            var enc1, enc2, enc3, enc4;
            var i = 0;
            var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

            input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

            while (i < input.length) {

                enc1 = keyStr.indexOf(input.charAt(i++));
                enc2 = keyStr.indexOf(input.charAt(i++));
                enc3 = keyStr.indexOf(input.charAt(i++));
                enc4 = keyStr.indexOf(input.charAt(i++));

                chr1 = (enc1 << 2) | (enc2 >> 4);
                chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
                chr3 = ((enc3 & 3) << 6) | enc4;

                output = output + String.fromCharCode(chr1);

                if (enc3 != 64) {
                    output = output + String.fromCharCode(chr2);
                }
                if (enc4 != 64) {
                    output = output + String.fromCharCode(chr3);
                }

            }

            return output;
        };
    }


    function getImageSize(imageArray) {
        var segments = slice2Segments(imageArray);
        var seg,
            width,
            height,
            SOF = [192, 193, 194, 195, 197, 198, 199, 201, 202, 203, 205, 206, 207];

        for (var x = 0; x < segments.length; x++) {
            seg = segments[x];
            if (SOF.indexOf(seg[1]) >= 0) {
                height = seg[5] * 256 + seg[6];
                width = seg[7] * 256 + seg[8];
                break;
            }
        }
        return [width, height];
    }


    function pack(mark, array) {
        if (!(array instanceof Array)) {
            throw ("'pack' error. Got invalid type argument.");
        }
        if ((mark.length - 1) != array.length) {
            throw ("'pack' error. " + (mark.length - 1) + " marks, " + array.length + " elements.");
        }

        var littleEndian;
        if (mark[0] == "<") {
            littleEndian = true;
        } else if (mark[0] == ">") {
            littleEndian = false;
        } else {
            throw ("");
        }
        var packed = "";
        var p = 1;
        var val = null;
        var c = null;
        var valStr = null;

        while (c = mark[p]) {
            if (c.toLowerCase() == "b") {
                val = array[p - 1];
                if ((c == "b") && (val < 0)) {
                    val += 0x100;
                }
                if ((val > 0xff) || (val < 0)) {
                    throw ("'pack' error.");
                } else {
                    valStr = String.fromCharCode(val);
                }
            } else if (c == "H") {
                val = array[p - 1];
                if ((val > 0xffff) || (val < 0)) {
                    throw ("'pack' error.");
                } else {
                    valStr = String.fromCharCode(Math.floor((val % 0x10000) / 0x100)) +
                        String.fromCharCode(val % 0x100);
                    if (littleEndian) {
                        valStr = valStr.split("").reverse().join("");
                    }
                }
            } else if (c.toLowerCase() == "l") {
                val = array[p - 1];
                if ((c == "l") && (val < 0)) {
                    val += 0x100000000;
                }
                if ((val > 0xffffffff) || (val < 0)) {
                    throw ("'pack' error.");
                } else {
                    valStr = String.fromCharCode(Math.floor(val / 0x1000000)) +
                        String.fromCharCode(Math.floor((val % 0x1000000) / 0x10000)) +
                        String.fromCharCode(Math.floor((val % 0x10000) / 0x100)) +
                        String.fromCharCode(val % 0x100);
                    if (littleEndian) {
                        valStr = valStr.split("").reverse().join("");
                    }
                }
            } else {
                throw ("'pack' error.");
            }

            packed += valStr;
            p += 1;
        }

        return packed;
    }

    function unpack(mark, str) {
        if (typeof (str) != "string") {
            throw ("'unpack' error. Got invalid type argument.");
        }
        var l = 0;
        for (var markPointer = 1; markPointer < mark.length; markPointer++) {
            if (mark[markPointer].toLowerCase() == "b") {
                l += 1;
            } else if (mark[markPointer].toLowerCase() == "h") {
                l += 2;
            } else if (mark[markPointer].toLowerCase() == "l") {
                l += 4;
            } else {
                throw ("'unpack' error. Got invalid mark.");
            }
        }

        if (l != str.length) {
            throw ("'unpack' error. Mismatch between symbol and string length. " + l + ":" + str.length);
        }

        var littleEndian;
        if (mark[0] == "<") {
            littleEndian = true;
        } else if (mark[0] == ">") {
            littleEndian = false;
        } else {
            throw ("'unpack' error.");
        }
        var unpacked = [];
        var strPointer = 0;
        var p = 1;
        var val = null;
        var c = null;
        var length = null;
        var sliced = "";

        while (c = mark[p]) {
            if (c.toLowerCase() == "b") {
                length = 1;
                sliced = str.slice(strPointer, strPointer + length);
                val = sliced.charCodeAt(0);
                if ((c == "b") && (val >= 0x80)) {
                    val -= 0x100;
                }
            } else if (c == "H") {
                length = 2;
                sliced = str.slice(strPointer, strPointer + length);
                if (littleEndian) {
                    sliced = sliced.split("").reverse().join("");
                }
                val = sliced.charCodeAt(0) * 0x100 +
                    sliced.charCodeAt(1);
            } else if (c.toLowerCase() == "l") {
                length = 4;
                sliced = str.slice(strPointer, strPointer + length);
                if (littleEndian) {
                    sliced = sliced.split("").reverse().join("");
                }
                val = sliced.charCodeAt(0) * 0x1000000 +
                    sliced.charCodeAt(1) * 0x10000 +
                    sliced.charCodeAt(2) * 0x100 +
                    sliced.charCodeAt(3);
                if ((c == "l") && (val >= 0x80000000)) {
                    val -= 0x100000000;
                }
            } else {
                throw ("'unpack' error. " + c);
            }

            unpacked.push(val);
            strPointer += length;
            p += 1;
        }

        return unpacked;
    }

    function nStr(ch, num) {
        var str = "";
        for (var i = 0; i < num; i++) {
            str += ch;
        }
        return str;
    }

    function splitIntoSegments(data) {
        if (data.slice(0, 2) != "\xff\xd8") {
            throw ("Given data isn't JPEG.");
        }

        var head = 2;
        var segments = ["\xff\xd8"];
        while (true) {
            if (data.slice(head, head + 2) == "\xff\xda") {
                segments.push(data.slice(head));
                break;
            } else {
                var length = unpack(">H", data.slice(head + 2, head + 4))[0];
                var endPoint = head + length + 2;
                segments.push(data.slice(head, endPoint));
                head = endPoint;
            }

            if (head >= data.length) {
                throw ("Wrong JPEG data.");
            }
        }
        return segments;
    }


    function getExifSeg(segments) {
        var seg;
        for (var i = 0; i < segments.length; i++) {
            seg = segments[i];
            if (seg.slice(0, 2) == "\xff\xe1" &&
                   seg.slice(4, 10) == "Exif\x00\x00") {
                return seg;
            }
        }
        return null;
    }


    function mergeSegments(segments, exif) {
        
        if (segments[1].slice(0, 2) == "\xff\xe0" &&
            (segments[2].slice(0, 2) == "\xff\xe1" &&
             segments[2].slice(4, 10) == "Exif\x00\x00")) {
            if (exif) {
                segments[2] = exif;
                segments = ["\xff\xd8"].concat(segments.slice(2));
            } else if (exif == null) {
                segments = segments.slice(0, 2).concat(segments.slice(3));
            } else {
                segments = segments.slice(0).concat(segments.slice(2));
            }
        } else if (segments[1].slice(0, 2) == "\xff\xe0") {
            if (exif) {
                segments[1] = exif;
            }
        } else if (segments[1].slice(0, 2) == "\xff\xe1" &&
                   segments[1].slice(4, 10) == "Exif\x00\x00") {
            if (exif) {
                segments[1] = exif;
            } else if (exif == null) {
                segments = segments.slice(0).concat(segments.slice(2));
            }
        } else {
            if (exif) {
                segments = [segments[0], exif].concat(segments.slice(1));
            }
        }
        
        return segments.join("");
    }


    function toHex(str) {
        var hexStr = "";
        for (var i = 0; i < str.length; i++) {
            var h = str.charCodeAt(i);
            var hex = ((h < 10) ? "0" : "") + h.toString(16);
            hexStr += hex + " ";
        }
        return hexStr;
    }


    var TYPES = {
        "Byte": 1,
        "Ascii": 2,
        "Short": 3,
        "Long": 4,
        "Rational": 5,
        "Undefined": 7,
        "SLong": 9,
        "SRational": 10
    };


    var TAGS = {
        'Image': {
            11: {
                'name': 'ProcessingSoftware',
                'type': 'Ascii'
            },
            254: {
                'name': 'NewSubfileType',
                'type': 'Long'
            },
            255: {
                'name': 'SubfileType',
                'type': 'Short'
            },
            256: {
                'name': 'ImageWidth',
                'type': 'Long'
            },
            257: {
                'name': 'ImageLength',
                'type': 'Long'
            },
            258: {
                'name': 'BitsPerSample',
                'type': 'Short'
            },
            259: {
                'name': 'Compression',
                'type': 'Short'
            },
            262: {
                'name': 'PhotometricInterpretation',
                'type': 'Short'
            },
            263: {
                'name': 'Threshholding',
                'type': 'Short'
            },
            264: {
                'name': 'CellWidth',
                'type': 'Short'
            },
            265: {
                'name': 'CellLength',
                'type': 'Short'
            },
            266: {
                'name': 'FillOrder',
                'type': 'Short'
            },
            269: {
                'name': 'DocumentName',
                'type': 'Ascii'
            },
            270: {
                'name': 'ImageDescription',
                'type': 'Ascii'
            },
            271: {
                'name': 'Make',
                'type': 'Ascii'
            },
            272: {
                'name': 'Model',
                'type': 'Ascii'
            },
            273: {
                'name': 'StripOffsets',
                'type': 'Long'
            },
            274: {
                'name': 'Orientation',
                'type': 'Short'
            },
            277: {
                'name': 'SamplesPerPixel',
                'type': 'Short'
            },
            278: {
                'name': 'RowsPerStrip',
                'type': 'Long'
            },
            279: {
                'name': 'StripByteCounts',
                'type': 'Long'
            },
            282: {
                'name': 'XResolution',
                'type': 'Rational'
            },
            283: {
                'name': 'YResolution',
                'type': 'Rational'
            },
            284: {
                'name': 'PlanarConfiguration',
                'type': 'Short'
            },
            290: {
                'name': 'GrayResponseUnit',
                'type': 'Short'
            },
            291: {
                'name': 'GrayResponseCurve',
                'type': 'Short'
            },
            292: {
                'name': 'T4Options',
                'type': 'Long'
            },
            293: {
                'name': 'T6Options',
                'type': 'Long'
            },
            296: {
                'name': 'ResolutionUnit',
                'type': 'Short'
            },
            301: {
                'name': 'TransferFunction',
                'type': 'Short'
            },
            305: {
                'name': 'Software',
                'type': 'Ascii'
            },
            306: {
                'name': 'DateTime',
                'type': 'Ascii'
            },
            315: {
                'name': 'Artist',
                'type': 'Ascii'
            },
            316: {
                'name': 'HostComputer',
                'type': 'Ascii'
            },
            317: {
                'name': 'Predictor',
                'type': 'Short'
            },
            318: {
                'name': 'WhitePoint',
                'type': 'Rational'
            },
            319: {
                'name': 'PrimaryChromaticities',
                'type': 'Rational'
            },
            320: {
                'name': 'ColorMap',
                'type': 'Short'
            },
            321: {
                'name': 'HalftoneHints',
                'type': 'Short'
            },
            322: {
                'name': 'TileWidth',
                'type': 'Short'
            },
            323: {
                'name': 'TileLength',
                'type': 'Short'
            },
            324: {
                'name': 'TileOffsets',
                'type': 'Short'
            },
            325: {
                'name': 'TileByteCounts',
                'type': 'Short'
            },
            330: {
                'name': 'SubIFDs',
                'type': 'Long'
            },
            332: {
                'name': 'InkSet',
                'type': 'Short'
            },
            333: {
                'name': 'InkNames',
                'type': 'Ascii'
            },
            334: {
                'name': 'NumberOfInks',
                'type': 'Short'
            },
            336: {
                'name': 'DotRange',
                'type': 'Byte'
            },
            337: {
                'name': 'TargetPrinter',
                'type': 'Ascii'
            },
            338: {
                'name': 'ExtraSamples',
                'type': 'Short'
            },
            339: {
                'name': 'SampleFormat',
                'type': 'Short'
            },
            340: {
                'name': 'SMinSampleValue',
                'type': 'Short'
            },
            341: {
                'name': 'SMaxSampleValue',
                'type': 'Short'
            },
            342: {
                'name': 'TransferRange',
                'type': 'Short'
            },
            343: {
                'name': 'ClipPath',
                'type': 'Byte'
            },
            344: {
                'name': 'XClipPathUnits',
                'type': 'Long'
            },
            345: {
                'name': 'YClipPathUnits',
                'type': 'Long'
            },
            346: {
                'name': 'Indexed',
                'type': 'Short'
            },
            347: {
                'name': 'JPEGTables',
                'type': 'Undefined'
            },
            351: {
                'name': 'OPIProxy',
                'type': 'Short'
            },
            512: {
                'name': 'JPEGProc',
                'type': 'Long'
            },
            513: {
                'name': 'JPEGInterchangeFormat',
                'type': 'Long'
            },
            514: {
                'name': 'JPEGInterchangeFormatLength',
                'type': 'Long'
            },
            515: {
                'name': 'JPEGRestartInterval',
                'type': 'Short'
            },
            517: {
                'name': 'JPEGLosslessPredictors',
                'type': 'Short'
            },
            518: {
                'name': 'JPEGPointTransforms',
                'type': 'Short'
            },
            519: {
                'name': 'JPEGQTables',
                'type': 'Long'
            },
            520: {
                'name': 'JPEGDCTables',
                'type': 'Long'
            },
            521: {
                'name': 'JPEGACTables',
                'type': 'Long'
            },
            529: {
                'name': 'YCbCrCoefficients',
                'type': 'Rational'
            },
            530: {
                'name': 'YCbCrSubSampling',
                'type': 'Short'
            },
            531: {
                'name': 'YCbCrPositioning',
                'type': 'Short'
            },
            532: {
                'name': 'ReferenceBlackWhite',
                'type': 'Rational'
            },
            700: {
                'name': 'XMLPacket',
                'type': 'Byte'
            },
            18246: {
                'name': 'Rating',
                'type': 'Short'
            },
            18249: {
                'name': 'RatingPercent',
                'type': 'Short'
            },
            32781: {
                'name': 'ImageID',
                'type': 'Ascii'
            },
            33421: {
                'name': 'CFARepeatPatternDim',
                'type': 'Short'
            },
            33422: {
                'name': 'CFAPattern',
                'type': 'Byte'
            },
            33423: {
                'name': 'BatteryLevel',
                'type': 'Rational'
            },
            33432: {
                'name': 'Copyright',
                'type': 'Ascii'
            },
            33434: {
                'name': 'ExposureTime',
                'type': 'Rational'
            },
            34377: {
                'name': 'ImageResources',
                'type': 'Byte'
            },
            34665: {
                'name': 'ExifTag',
                'type': 'Long'
            },
            34675: {
                'name': 'InterColorProfile',
                'type': 'Undefined'
            },
            34853: {
                'name': 'GPSTag',
                'type': 'Long'
            },
            34857: {
                'name': 'Interlace',
                'type': 'Short'
            },
            34858: {
                'name': 'TimeZoneOffset',
                'type': 'Long'
            },
            34859: {
                'name': 'SelfTimerMode',
                'type': 'Short'
            },
            37387: {
                'name': 'FlashEnergy',
                'type': 'Rational'
            },
            37388: {
                'name': 'SpatialFrequencyResponse',
                'type': 'Undefined'
            },
            37389: {
                'name': 'Noise',
                'type': 'Undefined'
            },
            37390: {
                'name': 'FocalPlaneXResolution',
                'type': 'Rational'
            },
            37391: {
                'name': 'FocalPlaneYResolution',
                'type': 'Rational'
            },
            37392: {
                'name': 'FocalPlaneResolutionUnit',
                'type': 'Short'
            },
            37393: {
                'name': 'ImageNumber',
                'type': 'Long'
            },
            37394: {
                'name': 'SecurityClassification',
                'type': 'Ascii'
            },
            37395: {
                'name': 'ImageHistory',
                'type': 'Ascii'
            },
            37397: {
                'name': 'ExposureIndex',
                'type': 'Rational'
            },
            37398: {
                'name': 'TIFFEPStandardID',
                'type': 'Byte'
            },
            37399: {
                'name': 'SensingMethod',
                'type': 'Short'
            },
            40091: {
                'name': 'XPTitle',
                'type': 'Byte'
            },
            40092: {
                'name': 'XPComment',
                'type': 'Byte'
            },
            40093: {
                'name': 'XPAuthor',
                'type': 'Byte'
            },
            40094: {
                'name': 'XPKeywords',
                'type': 'Byte'
            },
            40095: {
                'name': 'XPSubject',
                'type': 'Byte'
            },
            50341: {
                'name': 'PrintImageMatching',
                'type': 'Undefined'
            },
            50706: {
                'name': 'DNGVersion',
                'type': 'Byte'
            },
            50707: {
                'name': 'DNGBackwardVersion',
                'type': 'Byte'
            },
            50708: {
                'name': 'UniqueCameraModel',
                'type': 'Ascii'
            },
            50709: {
                'name': 'LocalizedCameraModel',
                'type': 'Byte'
            },
            50710: {
                'name': 'CFAPlaneColor',
                'type': 'Byte'
            },
            50711: {
                'name': 'CFALayout',
                'type': 'Short'
            },
            50712: {
                'name': 'LinearizationTable',
                'type': 'Short'
            },
            50713: {
                'name': 'BlackLevelRepeatDim',
                'type': 'Short'
            },
            50714: {
                'name': 'BlackLevel',
                'type': 'Rational'
            },
            50715: {
                'name': 'BlackLevelDeltaH',
                'type': 'SRational'
            },
            50716: {
                'name': 'BlackLevelDeltaV',
                'type': 'SRational'
            },
            50717: {
                'name': 'WhiteLevel',
                'type': 'Short'
            },
            50718: {
                'name': 'DefaultScale',
                'type': 'Rational'
            },
            50719: {
                'name': 'DefaultCropOrigin',
                'type': 'Short'
            },
            50720: {
                'name': 'DefaultCropSize',
                'type': 'Short'
            },
            50721: {
                'name': 'ColorMatrix1',
                'type': 'SRational'
            },
            50722: {
                'name': 'ColorMatrix2',
                'type': 'SRational'
            },
            50723: {
                'name': 'CameraCalibration1',
                'type': 'SRational'
            },
            50724: {
                'name': 'CameraCalibration2',
                'type': 'SRational'
            },
            50725: {
                'name': 'ReductionMatrix1',
                'type': 'SRational'
            },
            50726: {
                'name': 'ReductionMatrix2',
                'type': 'SRational'
            },
            50727: {
                'name': 'AnalogBalance',
                'type': 'Rational'
            },
            50728: {
                'name': 'AsShotNeutral',
                'type': 'Short'
            },
            50729: {
                'name': 'AsShotWhiteXY',
                'type': 'Rational'
            },
            50730: {
                'name': 'BaselineExposure',
                'type': 'SRational'
            },
            50731: {
                'name': 'BaselineNoise',
                'type': 'Rational'
            },
            50732: {
                'name': 'BaselineSharpness',
                'type': 'Rational'
            },
            50733: {
                'name': 'BayerGreenSplit',
                'type': 'Long'
            },
            50734: {
                'name': 'LinearResponseLimit',
                'type': 'Rational'
            },
            50735: {
                'name': 'CameraSerialNumber',
                'type': 'Ascii'
            },
            50736: {
                'name': 'LensInfo',
                'type': 'Rational'
            },
            50737: {
                'name': 'ChromaBlurRadius',
                'type': 'Rational'
            },
            50738: {
                'name': 'AntiAliasStrength',
                'type': 'Rational'
            },
            50739: {
                'name': 'ShadowScale',
                'type': 'SRational'
            },
            50740: {
                'name': 'DNGPrivateData',
                'type': 'Byte'
            },
            50741: {
                'name': 'MakerNoteSafety',
                'type': 'Short'
            },
            50778: {
                'name': 'CalibrationIlluminant1',
                'type': 'Short'
            },
            50779: {
                'name': 'CalibrationIlluminant2',
                'type': 'Short'
            },
            50780: {
                'name': 'BestQualityScale',
                'type': 'Rational'
            },
            50781: {
                'name': 'RawDataUniqueID',
                'type': 'Byte'
            },
            50827: {
                'name': 'OriginalRawFileName',
                'type': 'Byte'
            },
            50828: {
                'name': 'OriginalRawFileData',
                'type': 'Undefined'
            },
            50829: {
                'name': 'ActiveArea',
                'type': 'Short'
            },
            50830: {
                'name': 'MaskedAreas',
                'type': 'Short'
            },
            50831: {
                'name': 'AsShotICCProfile',
                'type': 'Undefined'
            },
            50832: {
                'name': 'AsShotPreProfileMatrix',
                'type': 'SRational'
            },
            50833: {
                'name': 'CurrentICCProfile',
                'type': 'Undefined'
            },
            50834: {
                'name': 'CurrentPreProfileMatrix',
                'type': 'SRational'
            },
            50879: {
                'name': 'ColorimetricReference',
                'type': 'Short'
            },
            50931: {
                'name': 'CameraCalibrationSignature',
                'type': 'Byte'
            },
            50932: {
                'name': 'ProfileCalibrationSignature',
                'type': 'Byte'
            },
            50934: {
                'name': 'AsShotProfileName',
                'type': 'Byte'
            },
            50935: {
                'name': 'NoiseReductionApplied',
                'type': 'Rational'
            },
            50936: {
                'name': 'ProfileName',
                'type': 'Byte'
            },
            50937: {
                'name': 'ProfileHueSatMapDims',
                'type': 'Long'
            },
            50938: {
                'name': 'ProfileHueSatMapData1',
                'type': 'Float'
            },
            50939: {
                'name': 'ProfileHueSatMapData2',
                'type': 'Float'
            },
            50940: {
                'name': 'ProfileToneCurve',
                'type': 'Float'
            },
            50941: {
                'name': 'ProfileEmbedPolicy',
                'type': 'Long'
            },
            50942: {
                'name': 'ProfileCopyright',
                'type': 'Byte'
            },
            50964: {
                'name': 'ForwardMatrix1',
                'type': 'SRational'
            },
            50965: {
                'name': 'ForwardMatrix2',
                'type': 'SRational'
            },
            50966: {
                'name': 'PreviewApplicationName',
                'type': 'Byte'
            },
            50967: {
                'name': 'PreviewApplicationVersion',
                'type': 'Byte'
            },
            50968: {
                'name': 'PreviewSettingsName',
                'type': 'Byte'
            },
            50969: {
                'name': 'PreviewSettingsDigest',
                'type': 'Byte'
            },
            50970: {
                'name': 'PreviewColorSpace',
                'type': 'Long'
            },
            50971: {
                'name': 'PreviewDateTime',
                'type': 'Ascii'
            },
            50972: {
                'name': 'RawImageDigest',
                'type': 'Undefined'
            },
            50973: {
                'name': 'OriginalRawFileDigest',
                'type': 'Undefined'
            },
            50974: {
                'name': 'SubTileBlockSize',
                'type': 'Long'
            },
            50975: {
                'name': 'RowInterleaveFactor',
                'type': 'Long'
            },
            50981: {
                'name': 'ProfileLookTableDims',
                'type': 'Long'
            },
            50982: {
                'name': 'ProfileLookTableData',
                'type': 'Float'
            },
            51008: {
                'name': 'OpcodeList1',
                'type': 'Undefined'
            },
            51009: {
                'name': 'OpcodeList2',
                'type': 'Undefined'
            },
            51022: {
                'name': 'OpcodeList3',
                'type': 'Undefined'
            }
        },
        'Exif': {
            33434: {
                'name': 'ExposureTime',
                'type': 'Rational'
            },
            33437: {
                'name': 'FNumber',
                'type': 'Rational'
            },
            34850: {
                'name': 'ExposureProgram',
                'type': 'Short'
            },
            34852: {
                'name': 'SpectralSensitivity',
                'type': 'Ascii'
            },
            34855: {
                'name': 'ISOSpeedRatings',
                'type': 'Short'
            },
            34856: {
                'name': 'OECF',
                'type': 'Undefined'
            },
            34864: {
                'name': 'SensitivityType',
                'type': 'Short'
            },
            34865: {
                'name': 'StandardOutputSensitivity',
                'type': 'Long'
            },
            34866: {
                'name': 'RecommendedExposureIndex',
                'type': 'Long'
            },
            34867: {
                'name': 'ISOSpeed',
                'type': 'Long'
            },
            34868: {
                'name': 'ISOSpeedLatitudeyyy',
                'type': 'Long'
            },
            34869: {
                'name': 'ISOSpeedLatitudezzz',
                'type': 'Long'
            },
            36864: {
                'name': 'ExifVersion',
                'type': 'Undefined'
            },
            36867: {
                'name': 'DateTimeOriginal',
                'type': 'Ascii'
            },
            36868: {
                'name': 'DateTimeDigitized',
                'type': 'Ascii'
            },
            37121: {
                'name': 'ComponentsConfiguration',
                'type': 'Undefined'
            },
            37122: {
                'name': 'CompressedBitsPerPixel',
                'type': 'Rational'
            },
            37377: {
                'name': 'ShutterSpeedValue',
                'type': 'SRational'
            },
            37378: {
                'name': 'ApertureValue',
                'type': 'Rational'
            },
            37379: {
                'name': 'BrightnessValue',
                'type': 'SRational'
            },
            37380: {
                'name': 'ExposureBiasValue',
                'type': 'SRational'
            },
            37381: {
                'name': 'MaxApertureValue',
                'type': 'Rational'
            },
            37382: {
                'name': 'SubjectDistance',
                'type': 'Rational'
            },
            37383: {
                'name': 'MeteringMode',
                'type': 'Short'
            },
            37384: {
                'name': 'LightSource',
                'type': 'Short'
            },
            37385: {
                'name': 'Flash',
                'type': 'Short'
            },
            37386: {
                'name': 'FocalLength',
                'type': 'Rational'
            },
            37396: {
                'name': 'SubjectArea',
                'type': 'Short'
            },
            37500: {
                'name': 'MakerNote',
                'type': 'Undefined'
            },
            37510: {
                'name': 'UserComment',
                'type': 'Ascii'
            },
            37520: {
                'name': 'SubSecTime',
                'type': 'Ascii'
            },
            37521: {
                'name': 'SubSecTimeOriginal',
                'type': 'Ascii'
            },
            37522: {
                'name': 'SubSecTimeDigitized',
                'type': 'Ascii'
            },
            40960: {
                'name': 'FlashpixVersion',
                'type': 'Undefined'
            },
            40961: {
                'name': 'ColorSpace',
                'type': 'Short'
            },
            40962: {
                'name': 'PixelXDimension',
                'type': 'Long'
            },
            40963: {
                'name': 'PixelYDimension',
                'type': 'Long'
            },
            40964: {
                'name': 'RelatedSoundFile',
                'type': 'Ascii'
            },
            40965: {
                'name': 'InteroperabilityTag',
                'type': 'Long'
            },
            41483: {
                'name': 'FlashEnergy',
                'type': 'Rational'
            },
            41484: {
                'name': 'SpatialFrequencyResponse',
                'type': 'Undefined'
            },
            41486: {
                'name': 'FocalPlaneXResolution',
                'type': 'Rational'
            },
            41487: {
                'name': 'FocalPlaneYResolution',
                'type': 'Rational'
            },
            41488: {
                'name': 'FocalPlaneResolutionUnit',
                'type': 'Short'
            },
            41492: {
                'name': 'SubjectLocation',
                'type': 'Short'
            },
            41493: {
                'name': 'ExposureIndex',
                'type': 'Rational'
            },
            41495: {
                'name': 'SensingMethod',
                'type': 'Short'
            },
            41728: {
                'name': 'FileSource',
                'type': 'Undefined'
            },
            41729: {
                'name': 'SceneType',
                'type': 'Undefined'
            },
            41730: {
                'name': 'CFAPattern',
                'type': 'Undefined'
            },
            41985: {
                'name': 'CustomRendered',
                'type': 'Short'
            },
            41986: {
                'name': 'ExposureMode',
                'type': 'Short'
            },
            41987: {
                'name': 'WhiteBalance',
                'type': 'Short'
            },
            41988: {
                'name': 'DigitalZoomRatio',
                'type': 'Rational'
            },
            41989: {
                'name': 'FocalLengthIn35mmFilm',
                'type': 'Short'
            },
            41990: {
                'name': 'SceneCaptureType',
                'type': 'Short'
            },
            41991: {
                'name': 'GainControl',
                'type': 'Short'
            },
            41992: {
                'name': 'Contrast',
                'type': 'Short'
            },
            41993: {
                'name': 'Saturation',
                'type': 'Short'
            },
            41994: {
                'name': 'Sharpness',
                'type': 'Short'
            },
            41995: {
                'name': 'DeviceSettingDescription',
                'type': 'Undefined'
            },
            41996: {
                'name': 'SubjectDistanceRange',
                'type': 'Short'
            },
            42016: {
                'name': 'ImageUniqueID',
                'type': 'Ascii'
            },
            42032: {
                'name': 'CameraOwnerName',
                'type': 'Ascii'
            },
            42033: {
                'name': 'BodySerialNumber',
                'type': 'Ascii'
            },
            42034: {
                'name': 'LensSpecification',
                'type': 'Rational'
            },
            42035: {
                'name': 'LensMake',
                'type': 'Ascii'
            },
            42036: {
                'name': 'LensModel',
                'type': 'Ascii'
            },
            42037: {
                'name': 'LensSerialNumber',
                'type': 'Ascii'
            },
            42240: {
                'name': 'Gamma',
                'type': 'Rational'
            }
        },
        'GPS': {
            0: {
                'name': 'GPSVersionID',
                'type': 'Byte'
            },
            1: {
                'name': 'GPSLatitudeRef',
                'type': 'Ascii'
            },
            2: {
                'name': 'GPSLatitude',
                'type': 'Rational'
            },
            3: {
                'name': 'GPSLongitudeRef',
                'type': 'Ascii'
            },
            4: {
                'name': 'GPSLongitude',
                'type': 'Rational'
            },
            5: {
                'name': 'GPSAltitudeRef',
                'type': 'Byte'
            },
            6: {
                'name': 'GPSAltitude',
                'type': 'Rational'
            },
            7: {
                'name': 'GPSTimeStamp',
                'type': 'Rational'
            },
            8: {
                'name': 'GPSSatellites',
                'type': 'Ascii'
            },
            9: {
                'name': 'GPSStatus',
                'type': 'Ascii'
            },
            10: {
                'name': 'GPSMeasureMode',
                'type': 'Ascii'
            },
            11: {
                'name': 'GPSDOP',
                'type': 'Rational'
            },
            12: {
                'name': 'GPSSpeedRef',
                'type': 'Ascii'
            },
            13: {
                'name': 'GPSSpeed',
                'type': 'Rational'
            },
            14: {
                'name': 'GPSTrackRef',
                'type': 'Ascii'
            },
            15: {
                'name': 'GPSTrack',
                'type': 'Rational'
            },
            16: {
                'name': 'GPSImgDirectionRef',
                'type': 'Ascii'
            },
            17: {
                'name': 'GPSImgDirection',
                'type': 'Rational'
            },
            18: {
                'name': 'GPSMapDatum',
                'type': 'Ascii'
            },
            19: {
                'name': 'GPSDestLatitudeRef',
                'type': 'Ascii'
            },
            20: {
                'name': 'GPSDestLatitude',
                'type': 'Rational'
            },
            21: {
                'name': 'GPSDestLongitudeRef',
                'type': 'Ascii'
            },
            22: {
                'name': 'GPSDestLongitude',
                'type': 'Rational'
            },
            23: {
                'name': 'GPSDestBearingRef',
                'type': 'Ascii'
            },
            24: {
                'name': 'GPSDestBearing',
                'type': 'Rational'
            },
            25: {
                'name': 'GPSDestDistanceRef',
                'type': 'Ascii'
            },
            26: {
                'name': 'GPSDestDistance',
                'type': 'Rational'
            },
            27: {
                'name': 'GPSProcessingMethod',
                'type': 'Undefined'
            },
            28: {
                'name': 'GPSAreaInformation',
                'type': 'Undefined'
            },
            29: {
                'name': 'GPSDateStamp',
                'type': 'Ascii'
            },
            30: {
                'name': 'GPSDifferential',
                'type': 'Short'
            },
            31: {
                'name': 'GPSHPositioningError',
                'type': 'Rational'
            }
        },
        'Interop': {
            1: {
                'name': 'InteroperabilityIndex',
                'type': 'Ascii'
            }
        },
    };
    TAGS["0th"] = TAGS["Image"];
    TAGS["1st"] = TAGS["Image"];
    that.TAGS = TAGS;

    
    that.ImageIFD = {
        ProcessingSoftware:11,
        NewSubfileType:254,
        SubfileType:255,
        ImageWidth:256,
        ImageLength:257,
        BitsPerSample:258,
        Compression:259,
        PhotometricInterpretation:262,
        Threshholding:263,
        CellWidth:264,
        CellLength:265,
        FillOrder:266,
        DocumentName:269,
        ImageDescription:270,
        Make:271,
        Model:272,
        StripOffsets:273,
        Orientation:274,
        SamplesPerPixel:277,
        RowsPerStrip:278,
        StripByteCounts:279,
        XResolution:282,
        YResolution:283,
        PlanarConfiguration:284,
        GrayResponseUnit:290,
        GrayResponseCurve:291,
        T4Options:292,
        T6Options:293,
        ResolutionUnit:296,
        TransferFunction:301,
        Software:305,
        DateTime:306,
        Artist:315,
        HostComputer:316,
        Predictor:317,
        WhitePoint:318,
        PrimaryChromaticities:319,
        ColorMap:320,
        HalftoneHints:321,
        TileWidth:322,
        TileLength:323,
        TileOffsets:324,
        TileByteCounts:325,
        SubIFDs:330,
        InkSet:332,
        InkNames:333,
        NumberOfInks:334,
        DotRange:336,
        TargetPrinter:337,
        ExtraSamples:338,
        SampleFormat:339,
        SMinSampleValue:340,
        SMaxSampleValue:341,
        TransferRange:342,
        ClipPath:343,
        XClipPathUnits:344,
        YClipPathUnits:345,
        Indexed:346,
        JPEGTables:347,
        OPIProxy:351,
        JPEGProc:512,
        JPEGInterchangeFormat:513,
        JPEGInterchangeFormatLength:514,
        JPEGRestartInterval:515,
        JPEGLosslessPredictors:517,
        JPEGPointTransforms:518,
        JPEGQTables:519,
        JPEGDCTables:520,
        JPEGACTables:521,
        YCbCrCoefficients:529,
        YCbCrSubSampling:530,
        YCbCrPositioning:531,
        ReferenceBlackWhite:532,
        XMLPacket:700,
        Rating:18246,
        RatingPercent:18249,
        ImageID:32781,
        CFARepeatPatternDim:33421,
        CFAPattern:33422,
        BatteryLevel:33423,
        Copyright:33432,
        ExposureTime:33434,
        ImageResources:34377,
        ExifTag:34665,
        InterColorProfile:34675,
        GPSTag:34853,
        Interlace:34857,
        TimeZoneOffset:34858,
        SelfTimerMode:34859,
        FlashEnergy:37387,
        SpatialFrequencyResponse:37388,
        Noise:37389,
        FocalPlaneXResolution:37390,
        FocalPlaneYResolution:37391,
        FocalPlaneResolutionUnit:37392,
        ImageNumber:37393,
        SecurityClassification:37394,
        ImageHistory:37395,
        ExposureIndex:37397,
        TIFFEPStandardID:37398,
        SensingMethod:37399,
        XPTitle:40091,
        XPComment:40092,
        XPAuthor:40093,
        XPKeywords:40094,
        XPSubject:40095,
        PrintImageMatching:50341,
        DNGVersion:50706,
        DNGBackwardVersion:50707,
        UniqueCameraModel:50708,
        LocalizedCameraModel:50709,
        CFAPlaneColor:50710,
        CFALayout:50711,
        LinearizationTable:50712,
        BlackLevelRepeatDim:50713,
        BlackLevel:50714,
        BlackLevelDeltaH:50715,
        BlackLevelDeltaV:50716,
        WhiteLevel:50717,
        DefaultScale:50718,
        DefaultCropOrigin:50719,
        DefaultCropSize:50720,
        ColorMatrix1:50721,
        ColorMatrix2:50722,
        CameraCalibration1:50723,
        CameraCalibration2:50724,
        ReductionMatrix1:50725,
        ReductionMatrix2:50726,
        AnalogBalance:50727,
        AsShotNeutral:50728,
        AsShotWhiteXY:50729,
        BaselineExposure:50730,
        BaselineNoise:50731,
        BaselineSharpness:50732,
        BayerGreenSplit:50733,
        LinearResponseLimit:50734,
        CameraSerialNumber:50735,
        LensInfo:50736,
        ChromaBlurRadius:50737,
        AntiAliasStrength:50738,
        ShadowScale:50739,
        DNGPrivateData:50740,
        MakerNoteSafety:50741,
        CalibrationIlluminant1:50778,
        CalibrationIlluminant2:50779,
        BestQualityScale:50780,
        RawDataUniqueID:50781,
        OriginalRawFileName:50827,
        OriginalRawFileData:50828,
        ActiveArea:50829,
        MaskedAreas:50830,
        AsShotICCProfile:50831,
        AsShotPreProfileMatrix:50832,
        CurrentICCProfile:50833,
        CurrentPreProfileMatrix:50834,
        ColorimetricReference:50879,
        CameraCalibrationSignature:50931,
        ProfileCalibrationSignature:50932,
        AsShotProfileName:50934,
        NoiseReductionApplied:50935,
        ProfileName:50936,
        ProfileHueSatMapDims:50937,
        ProfileHueSatMapData1:50938,
        ProfileHueSatMapData2:50939,
        ProfileToneCurve:50940,
        ProfileEmbedPolicy:50941,
        ProfileCopyright:50942,
        ForwardMatrix1:50964,
        ForwardMatrix2:50965,
        PreviewApplicationName:50966,
        PreviewApplicationVersion:50967,
        PreviewSettingsName:50968,
        PreviewSettingsDigest:50969,
        PreviewColorSpace:50970,
        PreviewDateTime:50971,
        RawImageDigest:50972,
        OriginalRawFileDigest:50973,
        SubTileBlockSize:50974,
        RowInterleaveFactor:50975,
        ProfileLookTableDims:50981,
        ProfileLookTableData:50982,
        OpcodeList1:51008,
        OpcodeList2:51009,
        OpcodeList3:51022,
        NoiseProfile:51041,
    };

    
    that.ExifIFD = {
        ExposureTime:33434,
        FNumber:33437,
        ExposureProgram:34850,
        SpectralSensitivity:34852,
        ISOSpeedRatings:34855,
        OECF:34856,
        SensitivityType:34864,
        StandardOutputSensitivity:34865,
        RecommendedExposureIndex:34866,
        ISOSpeed:34867,
        ISOSpeedLatitudeyyy:34868,
        ISOSpeedLatitudezzz:34869,
        ExifVersion:36864,
        DateTimeOriginal:36867,
        DateTimeDigitized:36868,
        ComponentsConfiguration:37121,
        CompressedBitsPerPixel:37122,
        ShutterSpeedValue:37377,
        ApertureValue:37378,
        BrightnessValue:37379,
        ExposureBiasValue:37380,
        MaxApertureValue:37381,
        SubjectDistance:37382,
        MeteringMode:37383,
        LightSource:37384,
        Flash:37385,
        FocalLength:37386,
        SubjectArea:37396,
        MakerNote:37500,
        UserComment:37510,
        SubSecTime:37520,
        SubSecTimeOriginal:37521,
        SubSecTimeDigitized:37522,
        FlashpixVersion:40960,
        ColorSpace:40961,
        PixelXDimension:40962,
        PixelYDimension:40963,
        RelatedSoundFile:40964,
        InteroperabilityTag:40965,
        FlashEnergy:41483,
        SpatialFrequencyResponse:41484,
        FocalPlaneXResolution:41486,
        FocalPlaneYResolution:41487,
        FocalPlaneResolutionUnit:41488,
        SubjectLocation:41492,
        ExposureIndex:41493,
        SensingMethod:41495,
        FileSource:41728,
        SceneType:41729,
        CFAPattern:41730,
        CustomRendered:41985,
        ExposureMode:41986,
        WhiteBalance:41987,
        DigitalZoomRatio:41988,
        FocalLengthIn35mmFilm:41989,
        SceneCaptureType:41990,
        GainControl:41991,
        Contrast:41992,
        Saturation:41993,
        Sharpness:41994,
        DeviceSettingDescription:41995,
        SubjectDistanceRange:41996,
        ImageUniqueID:42016,
        CameraOwnerName:42032,
        BodySerialNumber:42033,
        LensSpecification:42034,
        LensMake:42035,
        LensModel:42036,
        LensSerialNumber:42037,
        Gamma:42240,
    };


    that.GPSIFD = {
        GPSVersionID:0,
        GPSLatitudeRef:1,
        GPSLatitude:2,
        GPSLongitudeRef:3,
        GPSLongitude:4,
        GPSAltitudeRef:5,
        GPSAltitude:6,
        GPSTimeStamp:7,
        GPSSatellites:8,
        GPSStatus:9,
        GPSMeasureMode:10,
        GPSDOP:11,
        GPSSpeedRef:12,
        GPSSpeed:13,
        GPSTrackRef:14,
        GPSTrack:15,
        GPSImgDirectionRef:16,
        GPSImgDirection:17,
        GPSMapDatum:18,
        GPSDestLatitudeRef:19,
        GPSDestLatitude:20,
        GPSDestLongitudeRef:21,
        GPSDestLongitude:22,
        GPSDestBearingRef:23,
        GPSDestBearing:24,
        GPSDestDistanceRef:25,
        GPSDestDistance:26,
        GPSProcessingMethod:27,
        GPSAreaInformation:28,
        GPSDateStamp:29,
        GPSDifferential:30,
        GPSHPositioningError:31,
    };


    that.InteropIFD = {
        InteroperabilityIndex:1,
    };

    that.GPSHelper = {
        degToDmsRational:function (degFloat) {
            var minFloat = degFloat % 1 * 60;
            var secFloat = minFloat % 1 * 60;
            var deg = Math.floor(degFloat);
            var min = Math.floor(minFloat);
            var sec = Math.round(secFloat * 100);

            return [[deg, 1], [min, 1], [sec, 100]];
        }
    };
    
    
    if (typeof exports !== 'undefined') {
        if (typeof module !== 'undefined' && module.exports) {
            exports = module.exports = that;
        }
        exports.piexif = that;
    } else {
        window.piexif = that;
    }

})();