Viewing photos in Picasa (& other apps) - How do they know to auto rotate them?

NeilF · 16 Jul 2010 at 19:15

OK, I've got two photos taken with my Canon Ixus. One of which was taken on its side for a portrait photo.

With Picasa, and some other apps, when viewing that photo it knows to not show it in landscape more (as Windows viewer does), but instead show it rotated (correctly) to portrait mode.

How on earth do these apps know some photos were taken with the camera on its side so need rotating?

I've tested these photos on my media player, and even it rotates the appropriate ones too!?!

greedy123 · 16 Jul 2010 at 19:29

The camera embeds the orientation in the image Exif data when you take the photo.

ChazHurst · 16 Jul 2010 at 19:53

That mechanism, I imagine, is that most cameras have a basic tilt switch, which switches when you turn it beyond a certain angle thus telling the camera it's landscape or portrait... that 1 or 0 is then embedded in the appropriate place in the image.

NeilF · 16 Jul 2010 at 20:09

greedy123 said:
The camera embeds the orientation in the image Exif data when you take the photo.

Spot on! Thanks! I can see that tag