Get Field of View of an iOS7 Pano photo?

Question

For photos taken in Pano mode (which can vary up to 180 degrees depending on when you press stop) I want to load them into a pano viewer app.

But, there isn't anything in the EXIF data that can tell you the real field of view that the photo takes. The only differences between photos I take are the native resolution. But presumably that can change between devices.

                    Approx 180            Approx 90 
                    ----------            ---------
Exif Image Width    10800                 4176 
Exif Image Height   2332                  2462

Apparently Android writes XML meta data into their JPEGS:

http://atterer.org/tech/android-exif-tags-xmp-pano-panorama-exiftool

Any help appreciated!

Answer 1

First you need to calculate the pixels per degree that you are capturing. This can be done using the vertical angle of view and resolution.

The vertical angle of view will be dependent on the model of iphone and the orientation (landscape or portrait). For instance the iPhone 4 has a 55.7 x 43.2 degree angle of view iPhone 4 Camera Specifications - Field of View / Vertical-Horizontal Angle.

Divide the number of vertical pixels by the vertical angle of view, this will give you the pixels per degree. Then divide your panoramas horizontal number of pixels by the pixels per degree. This should give you the horizontal angle of view with enough accuracy for a good representation in a panorama viewer.