Moxiecode.MXI.Image.ExifParser.extractTags C# (CSharp) Метод

        private Dictionary<string, object> extractTags(long IFD_offset, Dictionary<int, string> tags2extract)
        {
            long length = data.SHORT(IFD_offset), i, ii;
            long type, count, tagOffset, offset;
            string tag;
             			string[] values;

            Dictionary<string, object> hash = new Dictionary<string, object>();

            for (i = 0; i < length; i++) {
                // Set binary reader pointer to beginning of the next tag
                offset = tagOffset = IFD_offset + 12 * i + 2;

                if (!tags2extract.TryGetValue((int)data.SHORT(offset), out tag)) {
                    continue; // Not the tag we requested
                }

                type = data.SHORT(offset+=2);
                count = data.LONG(offset+=2);
                values = new string[count];

                offset += 4;

                switch (type) {
                    case 1: // BYTE
                    case 7: // UNDEFINED
                        if (count > 4) {
                            offset = data.LONG(offset) + offsets["tiffHeader"];
                        }

                        for (ii = 0; ii < count; ii++) {
                            values[ii] = data.BYTE(offset + ii).ToString();
                        }
                        break;

                    case 2: // STRING
                        if (count > 4) {
                            offset = data.LONG(offset) + offsets["tiffHeader"];
                        }

                        hash.Add(tag, data.STRING(offset, (int)(count - 1)));
                        continue;

                    case 3: // SHORT
                        if (count > 2) {
                            offset = data.LONG(offset) + offsets["tiffHeader"];
                        }

                        for (ii = 0; ii < count; ii++) {
                            values[ii] = data.SHORT(offset + ii*2).ToString();
                        }
                        break;

                    case 4: // LONG
                        if (count > 1) {
                            offset = data.LONG(offset) + offsets["tiffHeader"];
                        }

                        for (ii = 0; ii < count; ii++) {
                            values[ii] = data.LONG(offset + ii*4).ToString();
                        }
                        break;

                    case 5: // RATIONAL
                        offset = data.LONG(offset) + offsets["tiffHeader"];

                        for (ii = 0; ii < count; ii++) {
                            values[ii] = ((double)data.LONG(offset + ii*8)/(double)data.LONG(offset + ii*8 + 4)).ToString();
                        }
                        break;

                    case 9: // SLONG
                        offset = data.LONG(offset) + offsets["tiffHeader"];

                        for (ii = 0; ii < count; ii++) {
                            values[ii] = data.SLONG(offset + ii*4).ToString();
                        }
                        break;

                    case 10: // SRATIONAL
                        offset = data.LONG(offset) + offsets["tiffHeader"];

                        for (ii = 0; ii < count; ii++) {
                            values[ii] = ((double)data.SLONG(offset + ii*8)/(double)data.SLONG(offset + ii*8 + 4)).ToString();
                        }
                        break;

                    default:
                        continue;
                }

                object details;
                string description;

                if (values.Length == 1)
                {
                    if (tagDescs.TryGetValue(tag, out details))
                    {
                        if (details is Dictionary<int, string> &&
                            ((Dictionary<int, string>)details).TryGetValue(Convert.ToInt32(values[0]), out description) ||
                            details is Dictionary<string, string> &&
                            ((Dictionary<string, string>)details).TryGetValue(values[0], out description))
                        {
                            hash[tag] = description;
                        }
                    }
                    else
                    {
                        hash[tag] = values[0];
                    }
                }
                else
                {
                    hash.Add(tag, values);
                }
            }

            return hash;
        }