In whatever way we store our pictures we are always faced with a very troublesome search if we are looking for a pictures of a particular person, or of several persons combined in one picture. In the past we had to tag all the pictures by hand to indicate which relevant persons were in the picture. In practice, this was too cumbersome. So, especially when we are busy, this is often not done.
However, a couple of years ago Face Recognition (FR) became feasible; it is becoming more and more popular, with many different applications. Also, the quality is improving although it is still far from perfect. FR software extracts special features from a picture or part of a picture. Based on these features it decided whether the picture contains a face and it can also distinguish different faces.
The algorithms that are used are very good to distinguish the various faces in the pictures. And at the same time they have to be very fast, to process a lot of pictures in a short time. On the surface, you might think that these algorithms are very intelligent, however, they just do mathematical computations on the pixels. Human beings use their intelligence to design these algorithms. Also, giving the faces the name of the corresponding person has to be done by hand.
If I look at the results, on the one hand, I am very impressed. With sometimes little information FR recognizes faces and is even able to identify that faces belong to the same person at different ages. On the other hand, there are also quite a bit of false hits: wrong person, no face detection when there is a person, or face detection when there is no face.
For picture handling I use Photo Mechanic and for image processing I use Adobe Lightroom. In Photo Mechanic I want to be able to search for persons, however, it does not have FR. Lightroom, on the other hand, has this facility. So, in practice, when processing images I let Lightroom identify the faces. It does this very fast. When exporting the pictures to DNG, the persons recognized are included in the DNG files. Allowing Photo Mechanic to search for persons. They are listed under Persons shown).
So, now I can search for a person or persons appearing together in a picture. I am very pleased with this set up. It saves me a lot of time.