Hand-Crafted System for Person Re-Identification:A Comprehensive Review

International audienceIn video surveillance, Person Re-Identification(Re-ID) consists in recognizing an individual who has already been observed (hence the term Re-Identification) over a network of cameras. Usually, the person Re-Id system is divided into two stages: i)constructing a person's appearance signature by extracting feature representations which should be robust against pose variations, illumination changes and occlusions and ii)Establishing the correspondence/matching between feature representations of probe and gallery by learning similarity metrics or ranking functions. A gallery is a dataset composed of images of people with known IDs whereas a probe is collected of detected persons with unknown IDs from different cameras. Specifically, the process of person Re-Identification aims essentially at matching individuals across non-overlapping cameras at different instants and locations. However, the matching is challenging due to disparities of human bodies and visual ambiguities across different cameras. This paper provides an overview of hand-crafted system for person Re-identification, including features extraction and metric learning as well as their advantages and drawbacks. The performance of some state-of-the-art person Re-ID methods on the commonly used benchmark datasets is compared and analyzed. It also provides a starting point for researchers who want to conduct novel investigations on this challenging topic

Tracklet and Signature Representation for Multi-shot Person Re-Identification.

International audienceVideo surveillance has become more and more important in many domains for their security andsafety. Person Re-Identification (Re-ID) is one of the most interesting subjects in this area. The Re-ID systemis divided into two main stages: i) extracting feature representations to construct a person’s appearance sig-nature and ii) establishing the correspondence/matching by learning similarity metrics or ranking functions.However, appearance based person Re-ID is a challenging task due to similarity of human’s appearance andvisual ambiguities across different cameras. This paper provides a representation of the appearance descriptors,called signatures, for multi-shot Re-ID. First, we will present the tracklets, i.e trajectories of persons. Then,we compute the signature and represent it based on the approach of Part Appearance Mixture (PAM). Anevaluation of the quality of this signature representation is also described in order to essentially solve the problemsof high variance in a person’s appearance, occlusions, illumination changes and person’s orientation/pose. Todeal with variance in a person’s appearance, we represent it as a set of multi-modal feature distributions modeledby Gaussian Mixture Model (GMM). Experiments and results on two public datasets and on our own datasetshow good performance

Absolute Environmental Sustainability of Materials Dissipation: Application for Construction Sector

The materials used globally in the construction sector are projected to more than double in 2060, causing some to deplete. We argue that access to the services that the resources provide must be protected, thus implying that a carrying capacity (CC) for resource dissipation must be set. Dissipation accrues when the resource becomes inaccessible to users. The CC allows defining a maximum dissipation rate that allows to maintain those resources’ availability in the future. The CC of the dissipation of the resource may be operationalized to characterize the resource use impact, using absolute environmental sustainability assessments principles. The study makes it possible to determine a dissipation CC as the world dissipation rate that would enable all users to adapt to using an alternative resource before the material’s reserve is entirely dissipated. The allocation of a fraction of this CC to the building sector was performed using equal per capita and grandfathering sharing principles. Finally, we applied the method to the case of steel in a school life cycle. The results show that the actual dissipation rates of iron, copper and manganese in the building sector exceed the dissipation CC by 70%, 56% and 68%, respectively. However, aluminum dissipation is 90% less than the assigned CC. The allocation to schools shows that the results are influenced by the choice of allocation principle. The application in the case of steel use of the school life cycle shows an exceedance of the CC that decreases when increasing the building life span

Absolute Environmental Sustainability of Materials Dissipation: Application for Construction Sector

The materials used globally in the construction sector are projected to more than double in 2060, causing some to deplete. We argue that access to the services that the resources provide must be protected, thus implying that a carrying capacity (CC) for resource dissipation must be set. Dissipation accrues when the resource becomes inaccessible to users. The CC allows defining a maximum dissipation rate that allows to maintain those resources’ availability in the future. The CC of the dissipation of the resource may be operationalized to characterize the resource use impact, using absolute environmental sustainability assessments principles. The study makes it possible to determine a dissipation CC as the world dissipation rate that would enable all users to adapt to using an alternative resource before the material’s reserve is entirely dissipated. The allocation of a fraction of this CC to the building sector was performed using equal per capita and grandfathering sharing principles. Finally, we applied the method to the case of steel in a school life cycle. The results show that the actual dissipation rates of iron, copper and manganese in the building sector exceed the dissipation CC by 70%, 56% and 68%, respectively. However, aluminum dissipation is 90% less than the assigned CC. The allocation to schools shows that the results are influenced by the choice of allocation principle. The application in the case of steel use of the school life cycle shows an exceedance of the CC that decreases when increasing the building life span

Tracklet and Signature Representation for Multi-shot Person Re-Identification.

International audienceVideo surveillance has become more and more important in many domains for their security andsafety. Person Re-Identification (Re-ID) is one of the most interesting subjects in this area. The Re-ID systemis divided into two main stages: i) extracting feature representations to construct a person’s appearance sig-nature and ii) establishing the correspondence/matching by learning similarity metrics or ranking functions.However, appearance based person Re-ID is a challenging task due to similarity of human’s appearance andvisual ambiguities across different cameras. This paper provides a representation of the appearance descriptors,called signatures, for multi-shot Re-ID. First, we will present the tracklets, i.e trajectories of persons. Then,we compute the signature and represent it based on the approach of Part Appearance Mixture (PAM). Anevaluation of the quality of this signature representation is also described in order to essentially solve the problemsof high variance in a person’s appearance, occlusions, illumination changes and person’s orientation/pose. Todeal with variance in a person’s appearance, we represent it as a set of multi-modal feature distributions modeledby Gaussian Mixture Model (GMM). Experiments and results on two public datasets and on our own datasetshow good performance

Exploring ecosystem services assessment through Ecological Footprint accounting

Ecosystem services are the benefits that humans derive from Nature. In the last decades, research efforts have been made to better understand the connections between the natural sphere and the human sphere as well as to propose novel approaches to measure the value of ecosystem services. While economic valuation has so far been the most commonly used approach – expressing ecosystem services’ value in monetary units – recent efforts have focused on alternative qualitative or biophysical accounting approaches to express the value of ecosystem service in physical units. The role of Ecological Footprint accounting as a biophysical approach for measuring the value of ecosystem services through a surface-equivalent unit is here investigated. This accounting tool allows keeping track of both the human demand on, and the Nature’s supply of, a precise sub-set of ecosystem services thus being able to make an ecological balance at the country level. A comparison between Ecological Footprint and economic valuation analyses is finally performed, for the forest ecosystem type, to highlight complementarities and correlations of these different approaches