Face detection is a hot research topic in Computer Vision; the field has greatly progressed over the past decade. However, to our knowledge, face detection in low-resolution images has not been studied. In this paper, we use a conventional AdaBoost-based face detector to show that the face detection rate falls to 39% from 88% as face resolution decreases from 24 x 24 pixels to 6 x 6 pixels. We propose a new face detection method comprising four techniques. As a result, our method improved the face detection rate from 39% to 71% for 6 x 6 pixel faces of MIT+CMU frontal face test set. We also show our method can detect 6x6 faces in real scene other than MIT+CMU frontal face test set.
['Shinji Hayashi', 'Osamu Hasegawa']
Detecting Faces from Low-Resolution Images