getOrentationofImage.js

function getOrientation(file, callback) {
            var reader = new FileReader();
            reader.onload = function (e) {

                var view = new DataView(e.target.result);
                if (view.getUint16(0, false) != 0xFFD8) return callback(-2);
                var length = view.byteLength, offset = 2;
                while (offset < length) {
                    var marker = view.getUint16(offset, false);
                    offset += 2;
                    if (marker == 0xFFE1) {
                        var little = view.getUint16(offset += 8, false) == 0x4949;
                        offset += view.getUint32(offset + 4, little);
                        var tags = view.getUint16(offset, little);
                        offset += 2;
                        for (var i = 0; i < tags; i++)
                            if (view.getUint16(offset + (i * 12), little) == 0x0112)
                                return callback(view.getUint16(offset + (i * 12) + 8, little));
                    }
                    else if ((marker & 0xFF00) != 0xFF00) break;
                    else offset += view.getUint16(offset, false);
                }
                return callback(-1);
            };
            reader.readAsArrayBuffer(file.slice(0, 64 * 1024));
        }