Design guidelines for embedded real time face detection application

White paper for Embedded Vision Alliance
By Eldad Melamed, CEVA

Much like the human visual system, embedded computer vision systems perform the same visual functions of analyzing and extracting information from video in a wide variety of products.

In embedded portable devices such as Smartphones, digital cameras, and camcorders, the elevated performance has to be delivered with limited size, cost, and power. Emerging high-volume embedded vision markets include automotive safety, surveillance, and gaming. Computer vision algorithms identify objects in a scene, and consequently produce one region of an image that has more importance than other regions of the image. For example, object and face detection can be used to enhance video conferencing experience, management of public security files, content based retrieval and many other aspects.

Cropping and resizing can be done to properly center the image on a face. In this paper we present an application that detects faces in digital image, crops the selected main face and resize it to a fixed size output image (see figure 1).

The application can be used on a single image or on a video stream, and is designed to run in real time. As far as real-time face detection on mobile devices is concerned, appropriate implementation steps need to be made in order to achieve a real-time throughput.

This paper presents such steps for real-time deployment of face detection application on programmable vector processor. The steps taken are general purpose in the sense that they can be used to implement similar computer vision algorithms on any mobile device.