Learning on 3D scene-based point cloud has received extensive attention as its promising application in many fields, and well-annotated and multisource datasets can catalyze the development of those data-driven approaches. To facilitate the research of this area, we present a richly-annotated 3D point cloud dataset for multiple outdoor scene understanding tasks and also an effective learning framework for its hierarchical segmentation task. The dataset was generated via the photogrammetric processing on unmanned aerial vehicle (UAV) images of the National University of Singapore (NUS) campus, and has been point-wisely annotated with both hierarchical and instance-based labels. Based on it, we formulate a hierarchical learning problem for 3D point cloud segmentation and propose a measurement evaluating consistency across various hierarchies. To solve this problem, a two-stage method including multi-task (MT) learning and hierarchical ensemble (HE) with consistency consideration is proposed. Experimental results demonstrate the superiority of the proposed method and potential advantages of our hierarchical annotations. In addition, we benchmark results of semantic and instance segmentation, which is accessible online at https://3d.dataset.site with the dataset and all source codes.

We propose a novel framework to localize and label affective objects and actions in images through a combination of text, visual and gaze-based analysis. Human gaze provides useful cues to infer locations and interactions of affective objects. While concepts (labels) associated with an image can be determined from its caption, we demonstrate localization of these concepts upon learning from a statistical affect model for world concepts. The affect model is derived from non-invasively acquired fixation patterns on labeled images, and guides localization of affective objects (faces, reptiles) and actions (look, read) from fixations in unlabeled images. Experimental results obtained on a database of 500 images confirm the effectiveness and promise of the proposed approach.