United States published patent application 20190050629, SELECTIVE IDENTITY RECOGNITION UTILIZING OBJECT TRACKING

The background section of the Amazon application states


Multimedia content such as video content is used in multiple settings
and presents many difficult challenges in the context of video processing,
such as recognizing and identifying objects moving through the multimedia content.
Multimedia content often includes large amount of information that make it challenging
to process the video to determine, for example, when a particular individual is present in the video.
Determining when a particular individual or other object is present
in the video may require performing an identity recognition process
and it may be computationally infeasible or inefficient to perform repeated identity recognition processes.



The first claim states:


A computer-implemented method, comprising: identifying a person in a first image
of the person in a video; detecting a loss of identification of the person;
detecting a second image of a person in the video; and determining whether
the person in the first image is the same as the person in the second image,
wherein the determining includes identifying a face of the person.