Sharing digital content with others is now an important part of human social activities. Despite the increasing need to share, most sharing operations are not simple. Many applications are not interoperable with others, require an Internet connection, or require cumbersome configuration and coordination efforts. Our idea is to simplify digital content sharing on mobile devices by providing support for self-organizing heterogeneous networks and pervasive storage. That is, mobile devices can spontaneously connect to each other over a mixture of different available networks (e.g., 3G/4G, WiFi, Bluetooth, etc.) without requiring an explicit user action of network selection or mandatory Internet access. Moreover, indirect communication can be further augmented by pervasive storage. Mobile devices can store shared content on it, which can later be automatically downloaded by other devices in proximity, thus allowing location-based sharing with minimal coordination even when devices are not in the same location at the same time. This paper shows how these technologies can be incorporated into mobile content-sharing middleware to simplify sharing operations among mobile devices without any modification to commercially available devices or applications. In particular, (i) we provide an implementation of our approach as extension modules for existing content-sharing middleware, (ii) we present two example applications built on top of it, and (iii) we demonstrate our approach through experiments in representative situations.

This ACM International Workshop on Immersive Media Experiences is in its 3rd edition. Since 2013 in Barcelona, it has been a meeting point of researchers, students, media producers, service providers and industry players in the area of immersive media environments, applications and experiences. After the successful first edition at ACM Multimedia 2013 and the consolidation of the theme and the team at Orlando in 2014, ImmersiveMe'15 aims at bringing to the stage new ideas and developments that keep this topic as appealing as in the previous editions. ImmersiveMe'15 will now take place in Brisbane and, again, it will be a platform to present interesting and out-of-the-box new work that contributes to make the world more interactive, immersive and engaging.

The 2nd ACM International Workshop on Immersive Media Experiences (ImmersiveMe'14) at ACM Multimedia aims at bringing together researchers, students, media producers, service providers and industry players in the emergent area of immersive media experiences, through the exploration of different scenarios, applications, and neighboring fields. This second edition, after a successful first edition at ACM Multimedia 2013, provides a platform for presenting on-going work, to consolidate and tie different research communities working on this engaging area, as well as to point directions for the future.

Immersive media has the potential for strong impact on users' emotions and their sense of presence and engagement. The main objective of this workshop is to bring together researchers, students, media producers, service providers and industry players in the area of emergent immersive media. The workshop will provide a platform for a deep discussion on ongoing work, recent achievements and experiences. It is expected not only to consolidate experiences but also to identify aspects where strong collaboration among all the interested players is needed and to point towards future working directions.

Holography, with its stunning 3-D realism and its expressive potential, in the 1970s and 1980s seemed poised to become the next step in the evolution of visual display. Yet apart from certain specialized niches, display holograms are perhaps more rarely encountered in everyday life than they were 20 or 30 years ago. But the recent resurgence of interest in 3-D video for entertainment applications has underlined the limitations of left/right stereoscopic imaging and created a desire for more natural 3-D imagery in which no glasses are required and all perceptual cues to depth are provided in a consistent fashion. Could holography-whose transition from darkroom to digital has taken some years longer than that of photography-capitalize on this opportunity? In this paper, I examine digital developments in holographic printing, holographic projection, and holographic television, and explore connections between holographic imaging and areas such as integral imaging and telepresence.

We have created a system which utilizes a pair of sensor-outfitted gloves to test for the performance of a series of multi-person gestures known as a "secret handshake." The fact that a new user of the system is required to rehearse the handshake performance with someone who is already experienced in performing it adds a novel layer of security to information access which is inherently social.

Pillow-Talk is the first of a series of objects designed to aid creative endeavors through the unobtrusive acquisition of unconscious self-generated content to permit reflexive self-knowledge. Composed of a seamless recording device embedded in a pillow and a playback and visualization system in a jar, Pillow-Talk crystallizes that which we normally forget. This allows users to capture their dreams in a less mediated way, aiding recollection by priming the experience and providing no distraction for recall and capture through embodied interaction.

The Graspables project is an exploration of how measuring the way people hold and manipulate objects can be used as a user interface. As computational ability continues to be implemented in more and more objects and devices, new interaction methods need to be developed. The Graspables System is embodied by a physical set of sensors combined with pattern recognition software that can determine how users hold a device. The Graspables System has been implemented in two prototypes, the Bar of Soap and the Ball of Soap. Applications developed for these prototypes demonstrate the effectiveness of grasp-recognition as an interface in multiple scenarios.

This paper presents "Connectibles," a prototype instantiation of a tangible social network, a new type of social network application rooted in physical objects and real world social behavior. This research is inspired by theoretical work that suggests that gifts act as physical symbols of social relationships. The Connectibles system leverages gift-giving practices, presenting users with gift objects ("connectibles") that they exchange with one another. These objects automatically form always-on communication channels between givers and receivers. As a user collects more and more of these objects, he or she begins to acquire a dynamic, physical representation of and interface to her social network. The community of users' interactions implicitly represent the structure of the social network; these data can be accessed with a GUI application, allowing users to explore and interact with their social network. This system was implemented and subject to three user studies. The overarching goal of this work is to examine how a set of devices might naturally and harmoniously interface the physical, virtual and social worlds.

Presents the welcome message from the conference proceedings.

Presents the welcome message from the conference proceedings.

We present bYOB (Build Your Own Bag), a flexible, computationally enhanced modular textile system from which to construct smart fabric objects. bYOB was motivated by a desire to transform everyday surfaces into ambient displays for information and to make building with fabric as easy as playing with Lego blocks. In the realm of personal architecture, bYOB is an interactive material that encourages users to explore and experiment by creating new objects to seamlessly integrate into their lives. The physical configuration of the object mediates its computational behavior. Therefore, an object built out of the system of modular elements understands its geometry and responds appropriately without any end-user programming. Our current prototype is a bag built out of the system that understands it is a bag when the handle is attached to the mesh of modules, responds by illuminating its fabric and inner contents when the sun goes down (Fig 1), communicates the presence of objects placed in the bag, and interacts with the user via speech. We describe how bYOB contributes to and differs from existing work in modular based systems and fabric interfaces. We discuss our development process in respect to physical, electronic, and conceptual design. We also describe salient features and future applications enabled by this new construction kit.

Automatic analysis of digital video scenes often requires the segmentation of moving objects from the background. Historically, algorithms developed for this purpose have been restricted to small frame sizes, low frame rates or offline processing. The simplest approach involves subtracting the current frame from the known background. However, as the background is unknown, the key is how to learn and model it. The paper proposes a new algorithm that represents each pixel in the frame by a group of clusters. The clusters are ordered according the likelihood that they model the background and are adapted to deal with background and lighting variations. Incoming pixels are matched against the corresponding cluster group and are classified according to whether the matching cluster is considered part of the background. The algorithm has been subjectively evaluated against three other techniques. It demonstrates equal or better segmentation than the other techniques and proves capable of processing 320/spl times/240 video at 28 fps, excluding post-processing.

Automatic analysis of digital video scenes often requires the segmentation of moving objects from the background. Historically, algorithms developed for this purpose have been restricted to small frame sizes, low frame rates or offline processing. The simplest approach involves subtracting the current frame from the known background. However, as the background is unknown, the key is how to learn and model it. This paper proposes a new algorithm that represents each pixel in the frame by a group of clusters. The clusters are ordered according the likelihood they model the background and are adapted to deal with background and lighting variations. Incoming pixels are matched against the corresponding cluster group and are classified according to whether the matching cluster is considered part of the background. The algorithm has been subjectively evaluated against three other techniques. It demonstrated equal or better segmentation than the other techniques and proved capable of processing 320 /spl times/ 240 video at 28 fps, excluding post-processing.

We consider the image-coding problem as a competitive ecology of specialists, each vying for the task of coding a portion of an image. Each specialist, or expert, derives its competitive advantage from its ability to concisely describe an underlying visual event (e.g., shadows, motion, occluding objects). In this paper, the metaphor of an auction informs the design of a predictive coder. Experts locate candidate regions of support, characterize the activity within, and submit their proposals in the form of bids passed along to an auctioneer. We describe the designs for six such experts, and examine candidate strategies for the decision unit (the auctioneer). We define protocols for comparing the bids, and compare overall coding performance using several examples.

Researchers have shown the compression advantages of coding video as a set of regions that can be defined by motion or texture models. Whether for purposes of compression efficiency, image editing, interactive multimedia authoring, or database search, it is often useful to be able to segment images or image sequences into regions corresponding to objects. We describe a segmentation scheme that takes account of multiple image characteristics, developing a multi-modal statistical model of regions based on a small amount of user-supplied training data.

The Cheops Imaging System is a compact, modular platform for acquisition, processing, and display of digital video sequences and model-based representations of moving scenes, and is intended as both a laboratory tool and a prototype architecture for future programmable video decoders. Rather than using a large number of general-purpose processors and dividing up image processing tasks spatially, Cheops abstracts out a set of basic, computationally intensive stream operations that may be performed in parallel and embodies them in specialized hardware. We review the Cheops architecture, describe the software system that has been developed to perform resource management, and present the results of some performance tests.>

Treating the temporal direction of subband-coded images has in the past involved a choice between temporal subband decomposition, which allows scalable (partial bit-stream) decoding but may reduce the coding efficiency, or motion-compensated coding, which can be more efficient but is not scalable. The authors propose a motion-compensated subband coder which preserves the scalability of the representation, and demonstrate its application in conjunction with a novel bit allocation process.>

Scalable video compression requires the creation of an encoded bit stream that may be decoded in part if channel bandwidth drops, decoder resources are limited, or a smaller image than the source is desired. A separable spatiotemporal subband decomposition is combined with vector and lattice quantizers modified so that the individual subbands may be decoded scalably. This results in finer bandwidth control and more flexibility than simply discarding entire subbands.>