45 research outputs found
Referring Expression Comprehension: A Survey of Methods and Datasets
Referring expression comprehension (REC) aims to localize a target object in
an image described by a referring expression phrased in natural language.
Different from the object detection task that queried object labels have been
pre-defined, the REC problem only can observe the queries during the test. It
thus more challenging than a conventional computer vision problem. This task
has attracted a lot of attention from both computer vision and natural language
processing community, and several lines of work have been proposed, from
CNN-RNN model, modular network to complex graph-based model. In this survey, we
first examine the state of the art by comparing modern approaches to the
problem. We classify methods by their mechanism to encode the visual and
textual modalities. In particular, we examine the common approach of joint
embedding images and expressions to a common feature space. We also discuss
modular architectures and graph-based models that interface with structured
graph representation. In the second part of this survey, we review the datasets
available for training and evaluating REC systems. We then group results
according to the datasets, backbone models, settings so that they can be fairly
compared. Finally, we discuss promising future directions for the field, in
particular the compositional referring expression comprehension that requires
longer reasoning chain to address.Comment: Accepted to IEEE TM
Localisation faiblement supervisée des actions orientées vers un but
The goal of this thesis is to develop methods for automatic understanding of video content. We focus on instructional videos that demonstrate how to perform complex tasks, such as making an omelette or hanging a picture. First, we investigate learning visual models for the steps of tasks, using only a list of steps for each task, instead of costly and time consuming human annotations. Our model allows us to share the information between the tasks on the sub-step level, effectively multiplying the amount of available training data. We demonstrate the benefits of our method on a newly collected dataset of instructional videos, CrossTask. Next, we present a method for isolating task-related actions from the surrounding background, that doesn’t rely on human supervision. Finally, we learn to associate natural language instructions with the corresponding objects within the 3D scene, reconstructed from the videos.Le but de cette thèse est de développer des méthodes pour la compréhension automatique des vidéos d'instructions, qui démontrent des tâches humaines, comme, par exemple, faire une omelette ou accrocher une peinture. Nous proposons, d’abord, une méthode d'apprentissage des actions seulement à partir d'un script pour chaque tâche, au lieu des annotations manuelles. Notre modèle permet de réduire la quantité de données d'entraînement, en partageant l’information entre les tâches. Nous évaluons notre approche sur un nouveau jeu de données, CrossTask. Nous présentons, ensuite, une méthode non supervisée pour isoler les actions, liée à une tâche de leur contexte. Finally, we learn to associate natural language instructions with the corresponding objects within the 3D scene, reconstructed from the videos. Finalement, nous proposons une approche pour associer des instructions textuelles avec des objets correspondants dans la scène 3D, reconstruite à partir des vidéos