{'fraction_non_alphanumeric': 0.020966271649954422, 'fraction_numerical': 0.011850501367365542, 'mean_word_length': 4.840425531914893, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Person real-time tracking for video communication

This paper presents a real-time head tracking method with a single black/white camera. This method mainly consists of two steps: block-based head tracking, and geometry-based correction. The block-based tracking method only uses low- level image information and can be used to track the free motion of the head. To improve the performance of block- based tracking during person turning around, we introduce a cylindrical model to approximate head, and extract features in the warped cylindrical surface. The correction step is introduced to address the shift caused by error accumulating of the block-based tracking method. This step utilizes the head contour geometry information, and measures the displacements between the head contour model and real contour in a current image, and hereby to correct the results of block tracking. We also set up a tracking system with a 350 megahertz microcomputer base on the proposed method, which operates at 30 frames per second with the tracking window size of 120 by 180 pixels and 80 tracking features.