EXIF Data
EXIF stands for Exchangeable Image File. EXIF data is low-level information stored in JPEG images. EXIF was created by the Japan Electronic Industries Development Association (JEIDA) and became a convention adopted across camera manufacturers, including on mobile devices. You can read about the EXIF format at http://en.wikipedia.org/wiki/Exchangeable_image_file_format and http://www.exif.org/Exif2-2.PDF.
EXIF data can include the date and time the image was created, the camera manufacturer and camera settings, location information, and even a thumbnail image. Visit Jeffrey Friedl’s website at http://regex.info/exif.cgi and load a JPEG image to see the information it contains.
In AIR for Android, you could use the geolocation API to get location information and associate it with the photo you just shot, but it is more efficient to get this information directly from the image if it is available. To store image location on an Android device when taking a picture, the user must have Location & Security→Use GPS Satellites selected and then turn on the camera’s Store Location option.
Several open source AS3 libraries are available for reading EXIF
data. I chose the one by Kenichi Ishibashi. You can download his library
using Subversion at http://code.shichiseki.jp/as3/ExifInfo/. Ishibashi’s
Loader class uses the loadBytes function and passes its data as a
ByteArray to access the raw data
information. Import his package to your class.
Our first example loads an image from the Gallery, ...
Get Developing Android Applications with Adobe AIR now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
