Our API directory now includes 203 photo APIs. The newest is the Getty Images Connect API. The most popular, in terms of mashups, is the Flickr API. We list 600 Flickr mashups. Below you'll find some more stats from the directory, including the entire list of photo APIs.
If you are building an image sharing service or a social network mashup, it's likely that you will want to incorporate face-tagging in your images. Maybe you'd like to go a step further and automatically detect faces in an image, similar to Apple's iPhoto. A Romanian developer has developed an API to help detect faces in images and return the box coordinates so that you can build any kind of app you want.
Instagram has deprecated much of its public API effective immediately. In a changelog published today, the popular Facebook-owned social media sharing platform announced that the endpoints for Follows and Relationships, Public Content Commenting, Likes and User Search have been removed.