10 research outputs found
Learning Temporal Transformations From Time-Lapse Videos
Based on life-long observations of physical, chemical, and biologic phenomena
in the natural world, humans can often easily picture in their minds what an
object will look like in the future. But, what about computers? In this paper,
we learn computational models of object transformations from time-lapse videos.
In particular, we explore the use of generative models to create depictions of
objects at future times. These models explore several different prediction
tasks: generating a future state given a single depiction of an object,
generating a future state given two depictions of an object at different times,
and generating future states recursively in a recurrent framework. We provide
both qualitative and quantitative evaluations of the generated results, and
also conduct a human evaluation to compare variations of our models.Comment: ECCV201
Learning, Moving, And Predicting With Global Motion Representations
In order to effectively respond to and influence the world they inhabit, animals and other intelligent agents must understand and predict the state of the world and its dynamics. An agent that can characterize how the world moves is better equipped to engage it. Current methods of motion computation rely on local representations of motion (such as optical flow) or simple, rigid global representations (such as camera motion). These methods are useful, but they are difficult to estimate reliably and limited in their applicability to real-world settings, where agents frequently must reason about complex, highly nonrigid motion over long time horizons. In this dissertation, I present methods developed with the goal of building more flexible and powerful notions of motion needed by agents facing the challenges of a dynamic, nonrigid world. This work is organized around a view of motion as a global phenomenon that is not adequately addressed by local or low-level descriptions, but that is best understood when analyzed at the level of whole images and scenes. I develop methods to: (i) robustly estimate camera motion from noisy optical flow estimates by exploiting the global, statistical relationship between the optical flow field and camera motion under projective geometry; (ii) learn representations of visual motion directly from unlabeled image sequences using learning rules derived from a formulation of image transformation in terms of its group properties; (iii) predict future frames of a video by learning a joint representation of the instantaneous state of the visual world and its motion, using a view of motion as transformations of world state. I situate this work in the broader context of ongoing computational and biological investigations into the problem of estimating motion for intelligent perception and action
Learning Beyond-pixel Mappings from Internet Videos
Recently in the Computer Vision community, there have been significant advancements in algorithms to recognize or localize visual contents for both images and videos, for instance, object recognition and detection tasks. They infer the information that is directly visible within the images or video frames (predicting what’s in the frame). While human-level visual understanding could be much more than that, because human also have insights about the information ’beyond the frame’. In other words, people are able to reasonably infer information that is not visible from the current scenes, such as predicting possible future events. We expect the computational models could own the same capabilities one day. Learning beyond-pixel mappings can be a broad concept. In this dissertation, we carefully define and formulate the problems as specific and subdivided tasks from different aspects. Under this context, what beyond-pixel mapping does is to infer information of broader spatial or temporal context, or even information from other modalities like text or sound. We first present a computational framework to learn the mappings between short event video clips and their intrinsic temporal sequence (which one usually happens first). Then we keep exploring the follow-up direction by directly predicting the future. Specifically we utilize generative models to predict depictions of objects in their future state. Next, we explore a related generation task to generate video frames of the target person with unseen poses guided by a random person. Finally, we propose a framework to learn the mappings between input video frames and it’s counterpart in sound domain. The main contribution of this dissertation lies in exploring beyond-pixel mappings from various directions to add relevant knowledge to the next-generation AI platforms.Doctor of Philosoph