Advanced Photo Properties

[Guest]

In Windows XP you can store advanced property information for JPG images, such as keywords, descriptions, and author information. Does anyone know where this information is stored? Is it stored in the image file's header, like EXIF information? Or is it in a hidden file? The data seems to travel with the image, so I thought perhaps it is stored in the image. However, when I open the files in EXIF-compliant programs and view the EXIF info, I don't see the items that I've entered into the Advanced Properties screen in Windows XP.

 

[David Candy]

It's stored in an alternative stream for non Compound Documents. Only NTFS supports more than one stream so it is lost if transfered outside an NTFS file system. Word, excel, et al are compound files. This is a large file with a file system inside. In these files multiple streams exist inside. It's stored inside the file and transfers with the file.

Windows only has very limited support for streams. While it's a core feature of windows and fully implemnented at a low level the higher level programs often have no idea what a stream is (eg, Explorer and most programs). The only program that can see a stream is the command prompt. And that is bare bones support (you have to know the name of the stream - there is no Dir equiv).

Copy con a.txt:stream1
This is stream 1
^z
type a.txt
type a.txt:stream1