1,962 research outputs found
Learning a Dilated Residual Network for SAR Image Despeckling
In this paper, to break the limit of the traditional linear models for
synthetic aperture radar (SAR) image despeckling, we propose a novel deep
learning approach by learning a non-linear end-to-end mapping between the noisy
and clean SAR images with a dilated residual network (SAR-DRN). SAR-DRN is
based on dilated convolutions, which can both enlarge the receptive field and
maintain the filter size and layer depth with a lightweight structure. In
addition, skip connections and residual learning strategy are added to the
despeckling model to maintain the image details and reduce the vanishing
gradient problem. Compared with the traditional despeckling methods, the
proposed method shows superior performance over the state-of-the-art methods on
both quantitative and visual assessments, especially for strong speckle noise.Comment: 18 pages, 13 figures, 7 table
Detecting Semantic Parts on Partially Occluded Objects
In this paper, we address the task of detecting semantic parts on partially
occluded objects. We consider a scenario where the model is trained using
non-occluded images but tested on occluded images. The motivation is that there
are infinite number of occlusion patterns in real world, which cannot be fully
covered in the training data. So the models should be inherently robust and
adaptive to occlusions instead of fitting / learning the occlusion patterns in
the training data. Our approach detects semantic parts by accumulating the
confidence of local visual cues. Specifically, the method uses a simple voting
method, based on log-likelihood ratio tests and spatial constraints, to combine
the evidence of local cues. These cues are called visual concepts, which are
derived by clustering the internal states of deep networks. We evaluate our
voting scheme on the VehicleSemanticPart dataset with dense part annotations.
We randomly place two, three or four irrelevant objects onto the target object
to generate testing images with various occlusions. Experiments show that our
algorithm outperforms several competitors in semantic part detection when
occlusions are present.Comment: Accepted to BMVC 2017 (13 pages, 3 figures
Deep Single-View 3D Object Reconstruction with Visual Hull Embedding
3D object reconstruction is a fundamental task of many robotics and AI
problems. With the aid of deep convolutional neural networks (CNNs), 3D object
reconstruction has witnessed a significant progress in recent years. However,
possibly due to the prohibitively high dimension of the 3D object space, the
results from deep CNNs are often prone to missing some shape details. In this
paper, we present an approach which aims to preserve more shape details and
improve the reconstruction quality. The key idea of our method is to leverage
object mask and pose estimation from CNNs to assist the 3D shape learning by
constructing a probabilistic single-view visual hull inside of the network. Our
method works by first predicting a coarse shape as well as the object pose and
silhouette using CNNs, followed by a novel 3D refinement CNN which refines the
coarse shapes using the constructed probabilistic visual hulls. Experiment on
both synthetic data and real images show that embedding a single-view visual
hull for shape refinement can significantly improve the reconstruction quality
by recovering more shapes details and improving shape consistency with the
input image.Comment: 11 page
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