APPLICATION OF LUCAS-KANADE DENSE FLOW FOR TERRAIN MOTION IN LANDSLIDE MONITORING APPLICATION

Landslides are natural hazards that can cause severe damage and loss of life. Optical cameras are a low-cost and high-resolution alternative among many monitoring systems, as their size and capabilities can vary, allowing for flexible implementation and location. Computer vision is a branch of artificial intelligence that can analyze and understand optical images, using techniques such as optical flow, image correlation and machine learning. The application of such techniques can estimate the motion vectors, displacement fields, providing valuable information for landslide detection, monitoring and prediction. However, computer vision also faces some challenges such as illumination changes, occlusions, image quality, and computational complexity. In this work, a computer vision approach based on Lucas-Kanade optical dense flow was applied to estimate the motion vectors between consecutive images obtained during landslide simulations in a laboratory environment. The approach is applied to two experiments that vary in their illumination and setup parameters to test its applicability. We also discuss the application of this methodology to images from Sentinel-2 satellite optical sensors for landslide monitoring in real-world scenarios

Dual sticky hierarchical Dirichlet process hidden Markov model and its application to natural language description of motions

In this paper, a new nonparametric Bayesian model called the dual sticky hierarchical Dirichlet process hidden Markov modle (HDP-HMM) is proposed for mining activities from a collection of time series data such as trajectories. All the time series data are clustered. Each cluster of time series data, corresponding to a motion pattern, is modeled by an HMM. Our model postulates a set of HMMs that share a common set of states (topics in an analogy with topic models for document processing), but have unique transition distributions. The number of HMMs and the number of topics are both automatically determined. The sticky prior avoids redundant states and makes our HDP-HMM more effective to model multimodal observations. For the application to motion trajectory modeling, topics correspond to motion activities. The learnt topics are clustered into atomic activities which are assigned predicates. We propose a Bayesian inference method to decompose a given trajectory into a sequence of atomic activities. The sources and sinks in the scene are learnt by clustering endpoints (origins and destinations of trajectories). The semantic motion regions are learnt using the points in trajectories. On combining the learnt sources and sinks, semantic motion regions, and the learnt sequences of atomic activities. the action represented by the trajectory can be described in natural language in as autometic a way as possible.The effectiveness of our dual sticky HDP-HMM is validated on several trajectory datasets. The effectiveness of the natural language descriptions for motions is demonstrated on the vehicle trajectories extracted from a traffic scene

Building an Understanding of Human Activities in First Person Video using Fuzzy Inference

Activities of Daily Living (ADL’s) are the activities that people perform every day in their home as part of their typical routine. The in-home, automated monitoring of ADL’s has broad utility for intelligent systems that enable independent living for the elderly and mentally or physically disabled individuals. With rising interest in electronic health (e-Health) and mobile health (m-Health) technology, opportunities abound for the integration of activity monitoring systems into these newer forms of healthcare. In this dissertation we propose a novel system for describing ’s based on video collected from a wearable camera. Most in-home activities are naturally defined by interaction with objects. We leverage these object-centric activity definitions to develop a set of rules for a Fuzzy Inference System (FIS) that uses video features and the identification of objects to identify and classify activities. Further, we demonstrate that the use of FIS enhances the reliability of the system and provides enhanced explainability and interpretability of results over popular machine-learning classifiers due to the linguistic nature of fuzzy systems

Understanding Human Actions in Video

Understanding human behavior is crucial for any autonomous system which interacts with humans. For example, assistive robots need to know when a person is signaling for help, and autonomous vehicles need to know when a person is waiting to cross the street. However, identifying human actions in video is a challenging and unsolved problem. In this work, we address several of the key challenges in human action recognition. To enable better representations of video sequences, we develop novel deep learning architectures which improve representations both at the level of instantaneous motion as well as at the level of long-term context. In addition, to reduce reliance on fixed action vocabularies, we develop a compositional representation of actions which allows novel action descriptions to be represented as a sequence of sub-actions. Finally, we address the issue of data collection for human action understanding by creating a large-scale video dataset, consisting of 70 million videos collected from internet video sharing sites and their matched descriptions. We demonstrate that these contributions improve the generalization performance of human action recognition systems on several benchmark datasets.PHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/162887/1/stroud_1.pd

Variational optic flow on the Sony PlayStation 3 – accurate dense flow fields for real-time applications

While modern variational methods for optic flow computation offer dense flow fields and highly accurate results, their computational complexity has prevented their use in many real-time applications. With cheap modern parallel hardware such as the Sony PlayStation 3 new possibilities arise. For a linear and a nonlinear variant of the popular combined local-global (CLG) method, we present specific algorithms that are tailored towards real-time performance. They are based on bidirectional full multigrid methods with a full approximation scheme (FAS) in the nonlinear setting. Their parallelisation on the Cell hardware uses a temporal instead of a spatial decomposition, and processes operations in a vector-based manner. Memory latencies are reduced by a locality-preserving cache management and optimised access patterns. With images of size 316×252 pixels, we obtain dense flow fields for up to 210 frames per second