This question originated here: Writing EXIF metadata to images in Android .
Can we use EXIF to write arbitrary metadata, i.e. other than those specified in the ExifInterface documentation (like latitude, longitude, flash etc). If not, what could be a preferred method of writing arbitrary metadata to image files?
The ExifInterface is only a very limited implementation of the EXIF standard and will not allow you to read/write tags other than the ones documented/defined. In the chosen answer of this post an alternative method is described.
Arbitrary data could be written to one of the following tags
Tag-hex Tag-dec IFD Key Type
0x010e 270 Image Exif.Image.ImageDescription Ascii
0x9286 37510 Photo Exif.Photo.UserComment Comment
whereby UserComment has less restrictions regarding the character set used
