Ugh. Such a simple thing became so complicated over the years. Most modern DSLR cameras and cell phones "do" rotation with a flag in the JPEG file header - this avoids processing the file to rotate it, plus it doesn't logically make sense to rotate the pixels in RAW. Confusion and grief ensues. Windows XP generally does not support the rotation flag. Applications vary greatly.
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Tools:
http://www.sentex.net/~mwandel/jhead/
http://jpegclub.org/jpegtran/
run: C:\tools\Win>jhead -ft -autorot J:**
then: dump thumbs.db to force cache rebuild (I think you just have to view folder thumbnails and it will rebuild, timestamp changes)
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Notes from the web:
Windows Picture and Fax Viewer
Surprisingly, the Windows Picture and Fax Viewer (built into Windows XP) and Windows Photo Viewer (built into Windows 7) do not support the EXIF orientation flag. This is surprising, as the makers have obviously thought enough to support lossless rotation functions. So, what you will see shown by the viewer is the real image data (assuming landscape orientation), without respecting any indication from the camera as to the real orientation of the image.
Beware of Rotating Photos in Windows Picture / Photo Viewer!
Another surprising detail is that if you decide to perform lossless image rotation (by using the Rotate Clockwise or Rotate CounterClockwise buttons), the EXIF Orientation flag is removed! As the flag is removed/reset, if you do a rotation followed by its reverse rotation on a portrait photo (eg. rotate clockwise, then rotate counter-clockwise), the resulting orientation observed by other viewers such as Photoshop will be wrong!
In fact, when you use the rotate functions of Windows Picutre Viewer, most of the image metadata (camera information, shot details, makernotes, etc.) are deleted. Therefore, I strongly recommend against using this program to rotate any of your digital photos.
I have also noticed that some images which were rotated that don't conform to 16x16 pixel multiples, the quantization tables don't appear to be rotated properly.
Because many new digital photographers may not be aware of this, Nikon even went so far as to issue a press release to warn of the potential dangers.
NOTE: The damage is done as soon as you press one of the rotate buttons . The disk icon is just for copying the file and should not be thought of as a Save button!
http://www.impulseadventure.com/photo/exif-orientation.html
And... http://keyj.emphy.de/exif-orientation-rant/
tags: exif, orientation