Unsupervised Object Modeling and Segmentation with Symmetry Detection for Human Activity Recognition

Abstract

Abstract:In this paper we present a novel unsupervised approach to detecting and segmenting objects as well as their constituent symmetric parts in an image. Traditional unsupervised image segmentation is limited by two obvious deficiencies: the object detection accuracy degrades with the misaligned boundaries between the segmented regions and the target, and pre-learned models are required to group regions into meaningful objects. To tackle these difficulties, the proposed approach aims at incorporating the pair-wise detection of symmetric patches to achieve the goal of segmenting images into symmetric parts. The skeletons of these symmetric parts then provide estimates of the bounding boxes to locate the target objects. Finally, for each detected object, the graphcut-based segmentation algorithm is applied to find its contour. The proposed approach has significant advantages: no a priori object models are used, and multiple objects are detected. To verify the effectiveness of the approach based on the cues that a face part contains an oval shape and skin colors, human objects are extracted from among the detected objects. The detected human objects and their parts are finally tracked across video frames to capture the object part movements for learning the human activity models from video clips. Experimental results show that the proposed method gives good performance on publicly available datasets.

Age Estimation-Based Soft Biometrics Considering Optical Blurring Based on Symmetrical Sub-Blocks for MLBP

“…In addition, they claimed that the human face is mostly appeared symmetrically. In another study [29], the symmetrical property of object's parts was used to detect the objects.…”

“…Based on these studies [28,29], we attempt to extract a strong image feature for human age estimation problem from symmetrical face. For this purpose, we first perform an in-plane rotation procedure to compensate the in-plane rotation of face and make the face region appears in symmetrical shape.…”