Face detection and blurring methods and systems

A method of face detection and blurring, comprising:

• receiving a plurality of images that captures a person traversing an interior of a room;
• processing, using a face detection algorithm, the plurality of images to identify an anchor image comprising a complete view of a face of the person and generating a bounding box for the face of the person;
• processing, using an optical region tracking algorithm, the plurality of images to identify a trajectory of the bounding box across the plurality of images;
• applying a blurring kernel over the bounding box across each of the plurality of images;
• determining a subset of images of the plurality of images, wherein a position of the bounding box is on the trajectory in each of the subset of images;
• and
• computing, based on the subset of images, a probability corresponding to the bounding box following the trajectory, wherein applying the blurring kernel is based on a comparison of the probability to a threshold,
• wherein the trajectory comprises a backward-in-time trajectory that tracks the bounding box from the anchor image to a first image of the plurality of images and a forward-in-time trajectory that tracks the bounding box from the anchor image to a last image of the plurality of images,
• wherein the optical region tracking algorithm refrains from using the face detection algorithm,
• wherein the trajectory tracks the bounding box based on a pixel-wise, frame-to-frame similarity of a region associated with the bounding box, and
• wherein at least the first image or the last image comprises a partial view of the face of the person and a partial bounding box.