We propose a new framework using Deep Neural Networks (DNNs) to obtain accurate light source estimation. Color constancy is formulated as a DNN-based regression approach to estimate the color of the light source.Traditional color constancy algorithms are constrained to a number of imaging assumptions or shallow learning models based on hand-crafted features. In this paper, instead of using traditional feature representations, we exploit deep learning architectures by means of Convolutional Neural Networks (CNN). Different from existing methods which rely on predefined low-level features, we propose to use CNNs to learn feature hierarchies to achieve robust color constancy. The deep CNN model used in this work consists of eight (hidden) layers. Such a deep model will yield multi-scale image features composed of pixels, edges, object parts and object models. The proposed deep learning approach needs large amounts of data with ground-truth for training. Unfortunately, there are no such datasets available for color constancy. Therefore, we propose a different training approach. Firstly, we propose a new training strategy which contains three steps to learn hierarchical features for color constancy. Secondly, we propose a method to generate more training images with ground-truth labels.The model used in this work consists of eight layers as defined in [3]. The first five layers are convolutional layers. The last three layers are fully collected layers. Combining all the layers, the total number of parameters in this model is very large (around 60M). Therefore, large scale datasets with ground-truth light source labels are required to directly apply this model to the color constancy problem. However, such large scale dataset are not available. To this end, we propose an alternative training procedure consisting of different training steps in the following section. Further, we proposed a data augmentation method to generate more training images with ground truth labels.The training contains three steps. In the first step, we train the model on ImageNet to derive features for object description. In this way, a rich and generic feature hierarchy is learnt to capture the complex visual patterns in generic, real-world images. The last layer of the model is replaced by a 1000 dimensional vector. The soft-max loss function is used for training. The aim of the first training step is to obtain a pre-trained feature model representing general images. Since the ImageNet dataset contains 1000 object categories, it provides abundant back-propagation information for training. We denote the parameters obtained by training on ImageNet as the Net1 network.In the second step of training, the aim is to retrain and adjust the parameters of Net1 for the purpose of color constancy. We perform retraining of the (initial) parameters of Net1 based on light source estimation obtained by existing color constancy algorithms as labels. Although any other or combination of color constancy algorithms can be used to generate the labels for the Image...
We present a novel latent discriminative model for human activity recognition. Unlike the approaches that require conditional independence assumptions, our model is very flexible in encoding the full connectivity among observations, latent states, and activity states. The model is able to capture richer class of contextual information in both statestate and observation-state pairs. Although loops are present in the model, we can consider the graphical model as a linearchain structure, where the exact inference is tractable. Thereby the model is very efficient in both inference and learning. The parameters of the graphical model are learned with the Structured-Support Vector Machine (Structured-SVM). A datadriven approach is used to initialize the latent variables, thereby no hand labeling for the latent states is required. Experimental results on the CAD-120 benchmark dataset show that our model outperforms the state-of-the-art approach by over 5% in both precision and recall, while our model is more efficient in computation.
A new stream of research and development responds to changes in life expectancy across the world. It includes technologies which enhance well-being of individuals, specifically for older people. The ACCOMPANY project focuses on home companion technologies and issues surrounding technology development for assistive purposes. The project responds to some overlooked aspects of technology design, divided into multiple areas such as empathic and social human-robot interaction, robot learning and memory visualisation, and monitoring persons’ activities at home. To bring these aspects together, a dedicated task is identified to ensure technological integration of these multiple approaches on an existing robotic platform, Care-O-Bot®3 in the context of a smart-home environment utilising a multitude of sensor arrays. Formative and summative evaluation cycles are then used to assess the emerging prototype towards identifying acceptable behaviours and roles for the robot, for example role as a butler or a trainer, while also comparing user requirements to achieved progress. In a novel approach, the project considers ethical concerns and by highlighting principles such as autonomy, independence, enablement, safety and privacy, it embarks on providing a discussion medium where user views on these principles and the existing tension between some of these principles, for example tension between privacy and autonomy over safety, can be captured and considered in design cycles and throughout project developments
With changes in life expectancy across the world, technologies enhancing well-being of individuals, specifically for older people, are subject to a new stream of research and development. In this paper we present the ACCOMPANY project, a pan-European project which focuses on home companion technologies. The projects aims to progress beyond the state of the art in multiple areas such as empathic and social humanrobot interaction, robot learning and memory visualisation, monitoring persons and chores at home, and technological integration of these multiple approaches on an existing robotic platform, Care-O-Bot R 3, and in the context of a smart-home environment utilising a multitude of sensor arrays. The resulting prototype from integrating these developments undergoes multiple formative cycles and a summative evaluation cycle towards identifying acceptable behaviours and roles for the robot for example role as a butler or a trainer. Furthermore, the evaluation activities will use an evaluation grid in order to assess achievement of the identified user requirements, formulated in form of distinct scenarios. Finally, the project considers ethical concerns and by highlighting principles such as autonomy, independence, enablement, safety and privacy, it embarks on providing a discussion medium where user views on these principles and the existing tension between some of these principles for example tension between privacy and autonomy over safety, can be captured and considered in design cyclesThe work described in this project was partially funded by the European project ACCOMPANY (Acceptable robotics COMPanions for AgeiNg Years). Grant agreement no.: 287624.
Abstract-An activity recognition system is a very important component for assistant robots, but training such a system usually requires a large and correctly labeled dataset. Most of the previous works only allow training data to have a single activity label per segment, which is overly restrictive because the labels are not always certain. It is, therefore, desirable to allow multiple labels for ambiguous segments. In this paper, we introduce the method of soft labeling, which allows annotators to assign multiple, weighted, labels to data segments. This is useful in many situations, e.g. when the labels are uncertain, when part of the labels are missing, or when multiple annotators assign inconsistent labels. We treat the activity recognition task as a sequential labeling problem. Latent variables are embedded to exploit sub-level semantics for better estimation. We propose a novel method for learning model parameters from soft-labeled data in a max-margin framework. The model is evaluated on a challenging dataset (CAD-120), which is captured by a RGB-D sensor mounted on the robot. To simulate the uncertainty in data annotation, we randomly change the labels for transition segments. The results show significant improvement over the state-of-the-art approach.
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