_Thumb
if (fThumbIndex >= 0 && _Thumb().data_offset) {
fRead.Seek(_Thumb().data_offset, SEEK_SET);
_Thumb().bits_per_sample = jh.bits;
_Thumb().width = jh.wide;
_Thumb().height = jh.high;
_Thumb().bits_per_sample = 16;
_Thumb().data_offset = fRead.Next<uint32>();
_Thumb().bytes = fRead.Next<uint32>();
_Thumb().data_offset = fRead.Position();
_Thumb().bytes = tag.length;
&& (_Thumb().data_offset = fRead.Next<uint32>())) {
_Thumb().data_offset += baseOffset;
_Thumb().bytes = fRead.Next<uint32>();
image_data_info& _Thumb();