Near the end of last year, I stumbled upon Orbeus -- a computer vision company that offers facial, object and scene recognition technology . This can be implemented using Orbeus' cloud-based ReKognition API. A ReKognition free Starter account allows one up to 5000 API monthly calls, with a limit of a single call per second and a tiny extra charge, if the maximum is exceeded. Using this API in Mathematica is pretty easy. Likewise, visualising the results. I have always been interested in this sort of tech and so I signed up for a free account to check it out.
Firstly, I acquired the images...
...then deployed them to Wolfram Cloud and imported them back into Mathematica. To use the API, a URL of the image is required, or a Base64 encoded version of it.
Here they are:
FindFaces in Mathematica:
Now, using ReKognition API: Creating the rectangles around the faces was a bit tricky. The results only give x and y positions, and width and height of the box around the face. It also returns the dimensions of the original image. So I used this information to create, what I believe, are the boxes around the faces.
A comparison between Mathematica and ReKognition:
Pretty similar, aye?
Furthermore, the API allows one to detect actual positions of facial features...
...as well as features such as race, age, gender and emotion.
Quite impressive. I am really keen on trying out the scene recognition.
 CrunchBase (2014) Orbeus, Available at: https://www.crunchbase.com/organization/orbeus (Accessed: 24th January 2015).