Hierarchical Structuring of Video Previews by Leading-Cluster-Analysis

3noClustering of shots is frequently used for accessing video data and enabling quick grasping of the associated content. In this work we first group video shots by a classic hierarchical algorithm, where shot content is described by a codebook of visual words and different codebooks are compared by a suitable measure of distortion. To deal with the high number of levels in a hierarchical tree, a novel procedure of Leading-Cluster-Analysis is then proposed to extract a reduced set of hierarchically arranged previews. The depth of the obtained structure is driven both from the nature of the visual content information, and by the user needs, who can navigate the obtained video previews at various levels of representation. The effectiveness of the proposed method is demonstrated by extensive tests and comparisons carried out on a large collection of video data. of digital videos has not been accompanied by a parallel increase in its accessibility. In this context, video abstraction techniques may represent a key components of a practical video management system: indeed a condensed video may be effective for a quick browsing or retrieval tasks. A commonly accepted type of abstract for generic videos does not exist yet, and the solutions investigated so far depend usually on the nature and the genre of video data.openopenBenini, Sergio; Migliorati, Pierangelo; Leonardi, RiccardoBenini, Sergio; Migliorati, Pierangelo; Leonardi, Riccard

Affective Recommendation of Movies Based on Selected Connotative Features

The apparent difficulty in assessing emotions elicited by movies and the undeniable high variability in subjects emotional responses to filmic content have been recently tackled by exploring film connotative properties: the set of shooting and editing conventions that help in transmitting meaning to the audience. Connotation provides an intermediate representation which exploits the objectivity of audiovisual descriptors to predict the subjective emotional reaction of single users. This is done without the need of registering users physiological signals neither by employing other people highly variable emotional rates, but just relying on the inter-subjectivity of connotative concepts and on the knowledge of users reactions to similar stimuli. This work extends previous by extracting audiovisual and film grammar descriptors and, driven by users rates on connotative properties, creates a shared framework where movie scenes are placed, compared and recommended according to connotation. We evaluate the potential of the proposed system by asking users to assess the ability of connotation in suggesting filmic content able to target their affective requests

Retrieval of video story units by Markov entropy rate

In this paper we propose a method to retrieve video stories from a database. Given a sample story unit, i.e., a series of contiguous and semantically related shots, the most similar clips are retrieved and ranked. Similarity is evaluated on the story structures, and it depends on the number of expressed visual concepts and the pattern in which they appear inside the story. Hidden Markov models are used to represent story units, and Markov entropy rate is adopted as a compact index for evaluating structure similarity. The effectiveness of the proposed approach is demonstrated on a large video set from different kinds of programmes, and results are evaluated by a developed prototype system for story unit retrieval

Statistical Skimming of Feature Films

We present a statistical framework based on Hidden Markov Models (HMMs) for skimming feature films. A chain of HMMs is used to model subsequent story units: HMM states represent different visual-concepts, transitions model the temporal dependencies in each story unit, and stochastic observations are given by single shots. The skim is generated as an observation sequence, where, in order to privilege more informative segments for entering the skim, shots are assigned higher probability of observation if endowed with salient features related to specific film genres. The effectiveness of the method is demonstrated by skimming the first thirty minutes of a wide set of action and dramatic movies, in order to create previews for users useful for assessing whether they would like to see that movie or not, but without revealing the movie central part and plot details. Results are evaluated and compared through extensive user tests in terms of metrics that estimate the content representational value of the obtained video skims and their utility for assessing the user's interest in the observed movie

A STATISTICAL FRAMEWORK FOR VIDEO SKIMMING BASED ON LOGICAL STORY UNITS AND MOTION ACTIVITY

In this work we present a method for video skimming based on hidden Markov Models (HMMs) and motion activity. Specifically, a set of HMMs is used to model subsequent log- ical story units, where the HMM states represent different visual-concepts, the transitions model the temporal dependencies in each story unit, and stochastic observations are given by single shots. The video skim is generated as an observation sequence, where, in order to privilege more informa- tive segments for entering the skim, dynamic shots are assigned higher probability of observation. The effectiveness of the method is demonstrated on a video set from different kinds of programmes, and results are evaluated in terms of metrics that measure the content representational value of the obtained video skims

Multimodal Space for Rushes Representation and Retrieval

In video content analysis, growing research effort aims at characterising a specific type of unedited content, called rushes. This raw material, used by broadcasters and film studios for editing video programmes, usually lies un-annotated in a huge database. In this work we aim at retrieving a desired type of rush by representing the whole database content in a multimodal space. Each rush content is mapped into a trajectory whose coordinates are connected to multimodal features and filming techniques used by cameramen while shooting. The trajectory evolution over time provides a strong characterisation of the video, so that different types of rushes are located into different regions of the multimodal space. The ability of the proposed method has been tested by retrieving similar rushes from a large database provided by EiTB, the Basque Country main broadcaster

Emotional Identity of Movies

4noIn the field of multimedia analysis, attempts that lead to an emotional characterization of content have been proposed. In this work we aim at defining the emotional identity of a feature movie by positioning it into an emotional space, as if it was a piece of art. The multimedia content is mapped into a trajectory whose coordinates are connected to filming and cinematographic techniques used by directors to convey emotions. The trajectory evolution over time provides a strong characterization of the movie, by locating different movies into different regions of the emotional space. The ability of this tool in characterizing content has been tested by retrieving emotionally similar movies from a large database, using IMDb genre classification for the evaluation of results.partially_openpartially_openL. CANINI; S. BENINI; P. MIGLIORATI; R. LEONARDICanini, Luca; Benini, Sergio; Migliorati, Pierangelo; Leonardi, Riccard

Trade-Offs between Energy Saving and Reliability in Low Duty Cycle Wireless Sensor Networks Using a Packet Splitting Forwarding Technique

One of the challenging topics and design constraints in Wireless Sensor Networks (WSNs) is the reduction of energy consumption because, in most application scenarios, replacement of power resources in sensor devices might be unfeasible. In order to minimize the power consumption, some nodes can be put to sleep during idle times and wake up only when needed. Although it seems the best way to limit the consumption of energy, other performance parameters such as network reliability have to be considered. In a recent paper, we introduced a new forwarding algorithm for WSNs based on a simple splitting procedure able to increase the network lifetime. The forwarding technique is based on the Chinese Remainder Theorem and exhibits very good results in terms of energy efficiency and complexity. In this paper, we intend to investigate a trade-off between energy efficiency and reliability of the proposed forwarding scheme when duty-cycling techniques are considered too

Salt marsh erosion rates and boundary features in a shallow Bay

Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Earth Surface 121 (2016): 1861–1875, doi:10.1002/2016JF003975.Herein, we investigate the relationship between wind waves, salt marsh erosion rates, and the planar shape of marsh boundaries by using aerial images and the numerical model Coupled-Ocean-Atmosphere-Wave-Sediment-Transport Modeling System (COAWST). Using Barnegat Bay, New Jersey, as a test site, we found that salt marsh erosion rates maintain a similar trend in time. We also found a significant relationship between salt marsh erosion rates and the shape of marsh boundaries which could be used as a geomorphic indicator of the degradation level of the marsh. Slowly eroding salt marshes are irregularly shaped with fractal dimension higher than rapidly deteriorating marshes. Moreover, for low-wave energy conditions, there is a high probability of isolated and significantly larger than average failures of marsh portions causing a long-tailed distribution of localized erosion rates. Finally, we confirm the existence of a significant relationship between salt marsh erosion rate and wind waves exposure. Results suggest that variations in time in the morphology of salt marsh boundaries could be used to infer changes in frequency and magnitude of external agents.Department of the Interior Hurricane Sandy Recovery program Grant Number: GS2-2D; NSF DEB Grant Number: 0621014; OCE Grant Number: 12382122017-04-2

FIGARO, Hair Detection and Segmentation in the Wild

Hair is one of the elements that mostly characterize people appearance. Being able to detect hair in images can be useful in many applications, such as face recognition, gender classification, and video surveillance. To this purpose we propose a novel multi-class image database for hair detection in the wild, called Figaro. We tackle the problem of hair detection without relying on a-priori information related to head shape and location. Without using any human-body part classifier, we first classify image patches into hair vs. non-hair by relying on Histogram of Gradients (HOG) and Linear Ternary Pattern (LTP) texture features in a random forest scheme. Then we obtain results at pixel level by refining classified patches by a graph-based multiple segmentation method. Achieved segmentation accuracy (85%) is comparable to state-of-the-art on less challenging databases