*PropertyItemId의 속성 https://msdn.microsoft.com/en-us/library/system.drawing.imaging.propertyitem.id(v=vs.110).aspxType의 속성 https://msdn.microsoft.com/ko-kr/library/system.drawing.imaging.propertyitem.type(v=vs.110).aspx메타데이터 reference http://www.exiv2.org/tags.htmlC#에서 바로 다루는 방법 http://motolies.com/186*ExifLibraryExifLib https://www.codeproject.com/Articles/36342/ExifLib-A-Fast-Exif-Data-Extract..