I'm using [exif](/questions/tagged/exif "show questions tagged 'exif'") data to carry captions for my images.

Using `exif_read_data` on localhost worked fine (with Apache on Ubuntu), but Heroku reports:

> 
> PHP Fatal error: Call to undefined function exif\_read\_data() in /app/path/to/files.
> 
> 
> 

I'm not really sure what to do here, looking at the error message it would appear that EXIF functions are not installed/enabled on my Heroku app. 

Can it be added or enabled?