1,439 research outputs found
New methods for deep dictionary learning and for image completion
Digital imaging plays an essential role in many aspects of our daily life. However due to the hardware limitations of the imaging devices, the image measurements are usually inpaired and require further processing to enhance the quality of the raw images in order to enable applications on the user side.
Image enhancement aims to improve the information content within image measurements by exploiting the properties of the target image and the forward model of the imaging device.
In this thesis, we aim to tackle two specific image enhancement problems, that is, single image super-resolution and image completion.
First, we present a new Deep Analysis Dictionary Model (DeepAM) which consists of multiple layers of analysis dictionaries with associated soft-thresholding operators and a single layer of synthesis dictionary for single image super-resolution. To achieve an effective deep model, each analysis dictionary has been designed to be composed of an Information Preserving Analysis Dictionary (IPAD) which passes essential information from the input signal to output and a Clustering Analysis Dictionary (CAD) which generates discriminative feature representation. The parameters of the deep analysis dictionary model are optimized using a layer-wise learning strategy. We demonstrate that both the proposed deep dictionary design and the learning algorithm are effective. Simulation results show that the proposed method achieves comparable performance with Deep Neural Networks and other existing methods.
We then generalize DeepAM to a Deep Convolutional Analysis Dictionary Model (DeepCAM) by learning convolutional dictionaries instead of unstructured dictionaries.
The convolutional dictionary is more suitable for processing high-dimensional signals like images and has only a small number of free parameters. By exploiting the properties of a convolutional dictionary, we present an efficient convolutional analysis dictionary learning algorithm. The IPAD and the CAD parts are learned using variations of the proposed convolutional analysis dictionary learning algorithm.
We demonstrate that DeepCAM is an effective multi-layer convolutional model and achieves better performance than DeepAM while using a smaller number of parameters.
Finally, we present an image completion algorithm based on dense correspondence between the input image and an exemplar image retrieved from Internet which has been taken at a similar position. The dense correspondence which is estimated using a hierarchical PatchMatch algorithm is usually noisy and with a large occlusion area corresponding to the region to be completed. By modelling the dense correspondence as a smooth field, an Expectation-Maximization (EM) based method is presented to interpolate a smooth field over the occlusion area which is then used to transfer image content from the exemplar image to the input image. Color correction is further applied to diminish the possible color differences between the input image and the exemplar image. Numerical results demonstrate that the proposed image completion algorithm is able to achieve photo realistic image completion results.Open Acces
Compare More Nuanced:Pairwise Alignment Bilinear Network For Few-shot Fine-grained Learning
The recognition ability of human beings is developed in a progressive way.
Usually, children learn to discriminate various objects from coarse to
fine-grained with limited supervision. Inspired by this learning process, we
propose a simple yet effective model for the Few-Shot Fine-Grained (FSFG)
recognition, which tries to tackle the challenging fine-grained recognition
task using meta-learning. The proposed method, named Pairwise Alignment
Bilinear Network (PABN), is an end-to-end deep neural network. Unlike
traditional deep bilinear networks for fine-grained classification, which adopt
the self-bilinear pooling to capture the subtle features of images, the
proposed model uses a novel pairwise bilinear pooling to compare the nuanced
differences between base images and query images for learning a deep distance
metric. In order to match base image features with query image features, we
design feature alignment losses before the proposed pairwise bilinear pooling.
Experiment results on four fine-grained classification datasets and one generic
few-shot dataset demonstrate that the proposed model outperforms both the
state-ofthe-art few-shot fine-grained and general few-shot methods.Comment: ICME 2019 Ora
Computing Lens for Exploring the Historical People's Social Network
A typical social research topic is to figure out the influential people's
relationship and its weights. It is very tedious for social scientists to solve
those problems by studying massive literature. Digital humanities bring a new
way to a social subject. In this paper, we propose a framework for social
scientists to find out ancient figures' power and their camp. The core of our
framework consists of signed graph model and novel group partition algorithm.
We validate and verify our solution by China Biographical Database Project
(CBDB) dataset. The analytic results on a case study demonstrate the
effectiveness of our framework, which gets information that consists with the
literature's facts and social scientists' viewpoints.Comment: accepted at SoNet 201
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