Current person re-identification (re-id) methods assume that (1) pre-labelled training data are available for every camera pair, (2) the gallery size for re-identification is moderate. Both assumptions scale poorly to real-world applications when camera network size increases and gallery size becomes large. Human verification of automatic model ranked re-id results becomes inevitable. In this work, a novel human-in-the-loop re-id model based on Human Verification Incremental Learning (HVIL) is formulated which does not require any pre-labelled training data to learn a model, therefore readily scalable to new camera pairs. This HVIL model learns cumulatively from human feedback to provide instant improvement to re-id ranking of each probe on-the-fly enabling the model scalable to large gallery sizes. We further formulate a Regularised Metric Ensemble Learning (RMEL) model to combine a series of incrementally learned HVIL models into a single ensemble model to be used when human feedback becomes unavailable.
@cite_30: 
@cite_18: For learning problems where human supervision is expensive, active query selection methods are often exploited to maximise the return of each supervision. Two problems where this has been successfully applied are active discovery --- where the aim is to discover at least one instance of each rare class with few supervisions; and active learning --- where the aim is to maximise a classifier's performance with least supervision. Recently, there has been interest in optimising these tasks jointly, i.e., active learning with undiscovered classes, to support efficient interactive modelling of new domains. Mixtures of active discovery and learning and other schemes have been exploited, but perform poorly due to heuristic objectives. In this study, we show with systematic theoretical analysis how the previously disparate tasks of active discovery and learning can be cleanly unified into a single problem, and hence are able for the first time to develop a unified query algorithm to directly optimise this problem. The result is a model which consistently outperforms previous attempts at active learning in the presence of undiscovered classes, with no need to tune parameters for different datasets.
@cite_7: 
@cite_48: We propose a visual recognition system that is designed for fine-grained visual categorization. The system is composed of a machine and a human user. The user, who is unable to carry out the recognition task by himself, is interactively asked to provide two heterogeneous forms of information: clicking on object parts and answering binary questions. The machine intelligently selects the most informative question to pose to the user in order to identify the object's class as quickly as possible. By leveraging computer vision and analyzing the user responses, the overall amount of human effort required, measured in seconds, is minimized. We demonstrate promising results on a challenging dataset of uncropped images, achieving a significant average reduction in human effort over previous methods.
@cite_96: We propose a scheme to introduce directionality in the random walker algorithm for image segmentation. In particular, we extend the optimization framework of this algorithm to combinatorial graphs with directed edges. Our scheme is interactive and requires the user to label a few pixels that are representative of a foreground object and of the background. These labeled pixels are used to learn intensity models for the object and the background, which allow us to automatically set the weights of the directed edges. These weights are chosen so that they bias the direction of the object boundary gradients to flow from regions that agree well with the learned object intensity model to regions that do not agree well. We use these weights to define an energy function that associates asymmetric quadratic penalties with the edges in the graph. We show that this energy function is convex, hence it has a unique minimizer. We propose a provably convergent iterative algorithm for minimizing this energy function. We also describe the construction of an equivalent electrical network with diodes and resistors that solves the same segmentation problem as our framework. Finally, our experiments on a database of 69 images show that the use of directional information does improve the segmenting power of the random Walker algorithm.
@cite_52: 
@cite_56: 
@cite_45: We analyze the nature of the relevance feedback problem in a continuous representation space in the context of content-based image retrieval. Emphasis is put on exploring the uniqueness of the problem and comparing the assumptions, implementations, and merits of various solutions in the literature. An attempt is made to compile a list of critical issues to consider when designing a relevance feedback algorithm. With a comprehensive review as the main portion, this paper also offers some novel solutions and perspectives throughout the discussion.
@cite_2: The problem of efficient, interactive foreground background segmentation in still images is of great practical importance in image editing. Classical image segmentation tools use either texture (colour) information, e.g. Magic Wand, or edge (contrast) information, e.g. Intelligent Scissors. Recently, an approach based on optimization by graph-cut has been developed which successfully combines both types of information. In this paper we extend the graph-cut approach in three respects. First, we have developed a more powerful, iterative version of the optimisation. Secondly, the power of the iterative algorithm is used to simplify substantially the user interaction needed for a given quality of result. Thirdly, a robust algorithm for "border matting" has been developed to estimate simultaneously the alpha-matte around an object boundary and the colours of foreground pixels. We show that for moderately difficult examples the proposed method outperforms competitive tools.
@cite_47: 
@cite_12: 
Interactive Learning Interactive model learning with human-in-the-loop is attractive for two reasons: (1) It provides a user with tools that can significantly alleviate or even eliminate the need for careful preparation of large-sized training data. (2) It allows to reduce the human labelling effort by exploiting a model's capacity interactively. Human-computer interactive models have been considered in image segmentation @cite_96 @cite_2 , object recognition @cite_56 @cite_48 , semi-supervised clustering @cite_30 and object counting @cite_7 . In addition, relevance feedback @cite_45 @cite_52 @cite_47 and active learning @cite_12 @cite_18 are also related to a similar idea of exploiting human feedback to improve model learning. The former has been exploited for interactive image retrieval where human feedback to search results are used to refine a query. The latter aims to reduce the human labelling effort by active sample selection for model training. In active learning, knowledge cumulation during model deployment is not considered, and some offline pre-labelled data are typically needed for model initialisation.