Posted to Flickr
What is EXIF data?
Almost all new digital cameras save JPEG (jpg) files with EXIF (Exchangeable Image File) data. Camera settings and scene information are recorded by the camera into the image file. Examples of stored information are shutter speed, date and time, focal length, exposure compensation, metering pattern and if a flash was used.
Interesting EXIF info (submitted by Bill Baron) from one of the original images:
* Camera Make = Apple
* Camera Model = iPhone
* Picture Orientation = rotated 90° (6)
* Lens F-Number/F-Stop = 14/5 = F2.80
* Color Space = sRGB (1)
* Image Width = 1600
* Image Height = 1200
* Unknown tag: Tagnum = 0xa500 ===> data = 11/5
* Compression = JPEG compression (6)
So, the Apple iPhone does appear to encode orientation information (landscape or portrait) into photos based on whether or not the phone is held vertically or horizontally.