540 research outputs found
Confidence Propagation through CNNs for Guided Sparse Depth Regression
Generally, convolutional neural networks (CNNs) process data on a regular
grid, e.g. data generated by ordinary cameras. Designing CNNs for sparse and
irregularly spaced input data is still an open research problem with numerous
applications in autonomous driving, robotics, and surveillance. In this paper,
we propose an algebraically-constrained normalized convolution layer for CNNs
with highly sparse input that has a smaller number of network parameters
compared to related work. We propose novel strategies for determining the
confidence from the convolution operation and propagating it to consecutive
layers. We also propose an objective function that simultaneously minimizes the
data error while maximizing the output confidence. To integrate structural
information, we also investigate fusion strategies to combine depth and RGB
information in our normalized convolution network framework. In addition, we
introduce the use of output confidence as an auxiliary information to improve
the results. The capabilities of our normalized convolution network framework
are demonstrated for the problem of scene depth completion. Comprehensive
experiments are performed on the KITTI-Depth and the NYU-Depth-v2 datasets. The
results clearly demonstrate that the proposed approach achieves superior
performance while requiring only about 1-5% of the number of parameters
compared to the state-of-the-art methods.Comment: 14 pages, 14 Figure
Resolution enhancement of video sequences by using discrete wavelet transform and illumination compensation
This research paper proposes a new technique for video resolution enhancement that employees an illumination
compensation procedure before the registration process. After the illumination compensation process,
the respective frames are registered using the Irani and Peleg technique. In parallel, the corresponding frame
is decomposed into high-frequency (low-high, high-low, and high-high) and low-frequency (low-low) subbands
using discrete wavelet transform (DWT). The high-frequency subbands are superresolved using bicubic interpolation.
Afterwards, the interpolated high-frequency subbands and superresolved low-frequency subband
obtained by registration are used to construct the high-resolution frame using inverse DWT. The superiority
of the proposed resolution enhancement method over well-known video superresolution techniques is shown
with quantitative experimental results. For the Akiyo video sequence, there are improvements of 2.26 dB
when compared to the average peak signal-to-noise ratio obtained by the state-of-the-art resolution technique
proposed by Vandewalle
Deformable Shape Completion with Graph Convolutional Autoencoders
The availability of affordable and portable depth sensors has made scanning
objects and people simpler than ever. However, dealing with occlusions and
missing parts is still a significant challenge. The problem of reconstructing a
(possibly non-rigidly moving) 3D object from a single or multiple partial scans
has received increasing attention in recent years. In this work, we propose a
novel learning-based method for the completion of partial shapes. Unlike the
majority of existing approaches, our method focuses on objects that can undergo
non-rigid deformations. The core of our method is a variational autoencoder
with graph convolutional operations that learns a latent space for complete
realistic shapes. At inference, we optimize to find the representation in this
latent space that best fits the generated shape to the known partial input. The
completed shape exhibits a realistic appearance on the unknown part. We show
promising results towards the completion of synthetic and real scans of human
body and face meshes exhibiting different styles of articulation and
partiality.Comment: CVPR 201
Joint Demosaicing and Super-Resolution Imaging from a Set of Unregistered Aliased Images
We present a new algorithm that performs demosaicing and super-resolution jointly from a set of raw images sampled with a color filter array. Such a combined approach allows us to compute the alignment parameters between the images on the raw camera data before interpolation artifacts are introduced. After image registration, a high resolution color image is reconstructed at once using the full set of images. For this, we use normalized convolution, an image interpolation method from a nonuniform set of samples. Our algorithm is tested and compared to other approaches in simulations and practical experiments
Demosaicing of Color Images by Accurate Estimation of Luminance
Digital cameras acquire color images using a single sensor with Color filter Arrays. A single color component per pixel is acquired using color filter arrays and the remaining two components are obtained using demosaicing techniques. The conventional demosaicing techniques existent induce artifacts in resultant images effecting reconstruction quality. To overcome this drawback a frequency based demosaicing technique is proposed. The luminance and chrominance components extracted from the frequency domain of the image are interpolated to produce intermediate demosaiced images. A novel Neural Network Based Image Reconstruction Algorithm is applied to the intermediate demosaiced image to obtain resultant demosaiced images. The results presented in the paper prove the proposed demosaicing technique exhibits the best performance and is applicable to a wide variety of images
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