Statistics for Spatial Data.

In 1974 an article appeared in Science magazine with the dry-sounding title “Judgment Under Uncertainty: Heuristics and Biases” by a pair of psychologists who were not well known outside their discipline of decision theory. In it Amos Tversky and Daniel Kahneman introduced the world to Prospect Theory, which mapped out how humans actually behave when faced with decisions about gains and losses, in contrast to how economists assumed that people behave. Prospect Theory turned Economics on its head by demonstrating through a series of ingenious experiments that people are much more concerned with losses than they are with gains, and that framing a choice from one perspective or the other will result in decisions that are exactly the opposite of each other, even if the outcomes are monetarily the same. Prospect Theory led cognitive psychology in a new direction that began to uncover other human biases in thinking that are probably not learned but are part of our brain’s wiring.

Thinking fast and slow.

Social Network Analysis

In 1997, Azuma published a survey on augmented reality (AR). Our goal is to complement, rather than replace, the original survey by presenting representative examples of the new advances. We refer one to the original survey for descriptions of potential applications (such as medical visualization, maintenance and repair of complex equipment, annotation, and path planning); summaries of AR system characteristics (such as the advantages and disadvantages of optical and video approaches to blending virtual and real, problems in display focus and contrast, and system portability); and an introduction to the crucial problem of registration, including sources of registration error and error-reduction strategies.

https://www.cc.gatech.edu/~blair/papers/ARsurveyCGA.pdf

Recent advances in augmented reality

Recently dense trajectories were shown to be an efficient video representation for action recognition and achieved state-of-the-art results on a variety of datasets. This paper improves their performance by taking into account camera motion to correct them. To estimate camera motion, we match feature points between frames using SURF descriptors and dense optical flow, which are shown to be complementary. These matches are, then, used to robustly estimate a homography with RANSAC. Human motion is in general different from camera motion and generates inconsistent matches. To improve the estimation, a human detector is employed to remove these matches. Given the estimated camera motion, we remove trajectories consistent with it. We also use this estimation to cancel out camera motion from the optical flow. This significantly improves motion-based descriptors, such as HOF and MBH. Experimental results on four challenging action datasets (i.e., Hollywood2, HMDB51, Olympic Sports and UCF50) significantly outperform the current state of the art.

/pdf/action-recognition-with-improved-trajectories-3z939q0pgz.pdf

Action Recognition with Improved Trajectories

We present novel optics and head-mounted display (HMD) prototypes, which have the widest reported field-of-view (FOV), and which can cover the full human FOV or even beyond They are based on lenses and screens which are curved around the eyes While this is still work-in-progress, the HMD prototypes and user tests suggest a feasible approach to significantly expand the FOV of HMDs

/pdf/extreme-field-of-view-for-head-mounted-displays-2xrscjrnah.pdf

Extreme field-of-view for head-mounted displays

In this paper we report an evaluation of keypoint descriptor compression using as little as 16 bits to describe a single keypoint. We use spectral hashing to compress keypoint descriptors, and match them using the Hamming distance. By indexing the keypoints in a binary tree, we can quickly recognize keypoints with a very small database, and efficiently insert new keypoints. Our tests using image datasets with perspective distortion show the method to enable fast keypoint recognition and image retrieval with a small code size, and point towards potential applications for scalable visual SLAM on mobile phones.

/pdf/fast-and-scalable-keypoint-recognition-and-image-retrieval-38ige3asj9.pdf

Fast and scalable keypoint recognition and image retrieval using binary codes

In Augmented Reality (AR) based remote collaboration, a remote user can draw a 2D annotation that emphasizes an object of interest to guide a local user accomplishing a task. This annotation is typically performed only once and then sticks to the selected object in the local user's view, independent of his or her camera movement. In this paper, we present an algorithm to segment the selected object, including its occluded surfaces, such that the 2D selection can be appropriately interpreted in 3D and rendered as a useful AR annotation even when the local user moves and significantly changes the viewpoint.

2D-3D Co-segmentation for AR-based Remote Collaboration.

We present a method for collaborative augmented reality (AR) that enables users from different viewpoints to interpret object references specified via 2D on-screen circling gestures. Based on a user's 2D drawing annotation, the method segments out the userselected object using an incomplete or imperfect scene model and the color image from the drawing viewpoint. Specifically, we propose a novel segmentation algorithm that utilizes both 2D and 3D scene cues, structured into a three-layer graph of pixels, 3D points, and volumes (supervoxels), solved via standard graph cut algorithms. This segmentation enables an appropriate rendering of the user's 2D annotation from other viewpoints in 3D augmented reality. Results demonstrate the superiority of the proposed method over existing methods.

PPV: Pixel-Point-Volume Segmentation for Object Referencing in Collaborative Augmented Reality

Augmented Reality interfaces increasingly utilize artificial intelligence systems to tailor content and experiences to the user. We explore the effects of one such system - a recommender system for online shopping - which allows customers to view personalized product recommendations in the physical spaces where they might be used. We describe results of a 2x3 condition exploratory study in which recommendation quality was varied across 3 user interface types. Our results highlight potential differences in user perception of the recommended objects in an AR environment. Specifically, users rate product recommendations significantly higher in AR and in a 3D browser interface, and show a significant increase in trust in the recommender system, compared to a web interface with 2D product images. Through semi-structured interviews, we gather participant feedback which suggests AR interfaces perform better due to their ability to view products within the physical context where they will be used.

Tobias Höllerer

Papers

Extreme field-of-view for head-mounted displays

Fast and scalable keypoint recognition and image retrieval using binary codes

2D-3D Co-segmentation for AR-based Remote Collaboration.

PPV: Pixel-Point-Volume Segmentation for Object Referencing in Collaborative Augmented Reality

A Study of Situated Product Recommendations in Augmented Reality