no code implementations • 2 Jun 2023 • Saghar Bagheri, Gene Cheung, Tim Eadie
Specifically, we first show that greedily removing an edge at a time that induces the minimal change in the second eigenvalue leads to a sparse graph with good GCN performance.
no code implementations • 1 Apr 2023 • Tam Thuc Do, Philip A. Chou, Gene Cheung
We study 3D point cloud attribute compression using a volumetric approach: given a target volumetric attribute function $f : \mathbb{R}^3 \rightarrow \mathbb{R}$, we quantize and encode parameter vector $\theta$ that characterizes $f$ at the encoder, for reconstruction $f_{\hat{\theta}}(\mathbf{x})$ at known 3D points $\mathbf{x}$'s at the decoder.
no code implementations • 25 Oct 2022 • Yuejiang Li, Hong Vicky Zhao, Gene Cheung
To minimize worst-case reconstruction error of the linear system solution $\mathbf{x}^* = \mathbf{C}^{-1} \mathbf{H}^\top \mathbf{y}$ with symmetric coefficient matrix $\mathbf{C} = \mathbf{H}^\top \mathbf{H} + \mu \mathbf{L}_{rw}^\top \mathbf{L}_{rw}$, the sampling objective is to choose $\mathbf{H}$ to maximize the smallest eigenvalue $\lambda_{\min}(\mathbf{C})$ of $\mathbf{C}$.
no code implementations • 18 Aug 2022 • Chinthaka Dinesh, Gene Cheung, Saghar Bagheri, Ivan V. Bajic
Experimental results show that our signed graph sampling method outperformed existing fast sampling schemes noticeably on various datasets.
no code implementations • 4 Aug 2022 • Saghar Bagheri, Chinthaka Dinesh, Gene Cheung, Timothy Eadie
Prediction of annual crop yields at a county granularity is important for national food production and price stability.
no code implementations • 9 Jun 2022 • Fei Chen, Gene Cheung, Xue Zhang
In the graph signal processing (GSP) literature, graph Laplacian regularizer (GLR) was used for signal restoration to promote piecewise smooth / constant reconstruction with respect to an underlying graph.
no code implementations • 2 Mar 2022 • Saghar Bagheri, Tam Thuc Do, Gene Cheung, Antonio Ortega
Transform coding to sparsify signal representations remains crucial in an image compression pipeline.
no code implementations • 28 Feb 2022 • Jin Zeng, Yang Liu, Gene Cheung, Wei Hu
Specifically, based on a spectral analysis of multilayer GCN output, we derive a spectrum prior for the graph Laplacian matrix $\mathbf{L}$ to robustify the model expressiveness against over-smoothing.
no code implementations • 15 Dec 2021 • Fei Chen, Gene Cheung, Xue Zhang
Experiments show that our embedding is among the fastest in the literature, while producing the best clustering performance for manifold graphs.
no code implementations • 9 Nov 2021 • Xue Zhang, Gene Cheung, Jiahao Pang, Yash Sanghvi, Abhiram Gnanasambandam, Stanley H. Chan
Specifically, we model depth formation as a combined process of signal-dependent noise addition and non-uniform log-based quantization.
no code implementations • 21 Oct 2021 • Sadid Sahami, Gene Cheung, Chia-Wen Lin
We prove that, after partitioning $\mathcal{G}$ into $Q$ sub-graphs $\{\mathcal{G}^q\}^Q_{q=1}$, the smallest Gershgorin circle theorem (GCT) lower bound of $Q$ corresponding coefficient matrices -- $\min_q \lambda^-_{\min}(\mathbf{B}^q)$ -- is a lower bound for $\lambda_{\min}(\mathbf{B})$.
no code implementations • 6 Oct 2021 • Fen Wang, Gene Cheung, Taihao Li, Ying Du, Yu-Ping Ruan
Sensor placement for linear inverse problems is the selection of locations to assign sensors so that the entire physical signal can be well recovered from partial observations.
no code implementations • 10 Sep 2021 • Cheng Yang, Gene Cheung, Wai-tian Tan, Guangtao Zhai
Algorithm unfolding creates an interpretable and parsimonious neural network architecture by implementing each iteration of a model-based algorithm as a neural layer.
no code implementations • NeurIPS 2021 • Cheng Yang, Gene Cheung, Guangtao Zhai
We repose the SDR dual for solution $\bar{\mathbf{H}}$, then replace the PSD cone constraint $\bar{\mathbf{H}} \succeq 0$ with linear constraints derived from GDPA -- sufficient conditions to ensure $\bar{\mathbf{H}}$ is PSD -- so that the optimization becomes an LP per iteration.
no code implementations • 10 Mar 2021 • Chinthaka Dinesh, Gene Cheung, Ivan Bajic
Specifically, to articulate a sampling objective, we first assume a super-resolution (SR) method based on feature graph Laplacian regularization (FGLR) that reconstructs the original high-resolution PC, given 3D points chosen by a sampling matrix $\H$.
no code implementations • 15 Feb 2021 • Yung-Hsuan Chao, Haoran Hong, Gene Cheung, Antonio Ortega
Using a conventional Bayer pattern, data captured at each pixel is a single color component (R, G or B). The sensed data then undergoes demosaicking (interpolation of RGB components per pixel) and conversion to an array of sub-aperture images (SAIs).
no code implementations • 25 Jan 2021 • Fei Chen, Gene Cheung, Xue Zhang
In the graph signal processing (GSP) literature, it has been shown that signal-dependent graph Laplacian regularizer (GLR) can efficiently promote piecewise constant (PWC) signal reconstruction for various image restoration tasks.
no code implementations • 25 Oct 2020 • Saghar Bagheri, Gene Cheung, Antonio Ortega, Fen Wang
Learning a suitable graph is an important precursor to many graph signal processing (GSP) pipelines, such as graph spectral signal compression and denoising.
1 code implementation • 21 Oct 2020 • Huy Vu, Gene Cheung, Yonina C. Eldar
While deep learning (DL) architectures like convolutional neural networks (CNNs) have enabled effective solutions in image denoising, in general their implementations overly rely on training data, lack interpretability, and require tuning of a large parameter set.
1 code implementation • 15 Jun 2020 • Cheng Yang, Gene Cheung, Wei Hu
Given a convex and differentiable objective $Q(\M)$ for a real symmetric matrix $\M$ in the positive definite (PD) cone -- used to compute Mahalanobis distances -- we propose a fast general metric learning framework that is entirely projection-free.
no code implementations • 9 Mar 2020 • Yuichi Tanaka, Yonina C. Eldar, Antonio Ortega, Gene Cheung
In this article, we review current progress on sampling over graphs focusing on theory and potential applications.
no code implementations • 28 Jan 2020 • Cheng Yang, Gene Cheung, Wei Hu
We propose a fast general projection-free metric learning framework, where the minimization objective $\min_{\textbf{M} \in \mathcal{S}} Q(\textbf{M})$ is a convex differentiable function of the metric matrix $\textbf{M}$, and $\textbf{M}$ resides in the set $\mathcal{S}$ of generalized graph Laplacian matrices for connected graphs with positive edge weights and node degrees.
no code implementations • 6 Dec 2019 • Minxiang Ye, Vladimir Stankovic, Lina Stankovic, Gene Cheung
In this paper, we propose a robust binary classifier, based on CNNs, to learn deep metric functions, which are then used to construct an optimal underlying graph structure used to clean noisy labels via graph Laplacian regularization (GLR).
no code implementations • 22 Jul 2019 • Wei Hu, Xiang Gao, Gene Cheung, Zongming Guo
In this work, we assume instead the availability of a relevant feature vector $\mathbf{f}_i$ per node $i$, from which we compute an optimal feature graph via optimization of a feature metric.
1 code implementation • 31 Jul 2018 • Jin Zeng, Jiahao Pang, Wenxiu Sun, Gene Cheung
In this work, we combine the robustness merit of model-based approaches and the learning power of data-driven approaches for real image denoising.
1 code implementation • 22 Jul 2018 • Chih-Chung Hsu, Chia-Wen Lin, Weng-Tai Su, Gene Cheung
Despite generative adversarial networks (GANs) can hallucinate photo-realistic high-resolution (HR) faces from low-resolution (LR) faces, they cannot guarantee preserving the identities of hallucinated HR faces, making the HR faces poorly recognizable.
no code implementations • 20 Mar 2018 • Jin Zeng, Gene Cheung, Michael Ng, Jiahao Pang, Cheng Yang
Due to discrete observations of the patches on the manifold, we approximate the manifold dimension computation defined in the continuous domain with a patch-based graph Laplacian regularizer and propose a new discrete patch distance measure to quantify the similarity between two same-sized surface patches for graph construction that is robust to noise.
no code implementations • 22 Feb 2018 • Yuanchao Bai, Gene Cheung, Xian-Ming Liu, Wen Gao
We leverage the new graph spectral interpretation for RGTV to design an efficient algorithm that solves for the skeleton image and the blur kernel alternately.
no code implementations • 20 Feb 2018 • Qi Chang, Gene Cheung, Yao Zhao, Xiaolong Li, Rongrong Ni
If sufficiently smooth, we pose a maximum a posteriori (MAP) problem using either a quadratic Laplacian regularizer or a graph total variation (GTV) term as signal prior.
no code implementations • 24 Dec 2017 • Yuanchao Bai, Gene Cheung, Xian-Ming Liu, Wen Gao
The problem can be solved in two parts: i) estimate a blur kernel from the blurry image, and ii) given estimated blur kernel, de-convolve blurry input to restore the target image.
no code implementations • 30 Apr 2017 • Amin Zheng, Gene Cheung, Dinei Florencio
We first prove theoretically that in general a joint denoising / compression approach can outperform a separate two-stage approach that first denoises then encodes contours lossily.
no code implementations • 10 Feb 2017 • Weng-Tai Su, Gene Cheung, Chia-Wen Lin
Recent advent in graph signal processing (GSP) has led to the development of new graph-based transforms and wavelets for image / video coding, where the underlying graph describes inter-pixel correlations.
no code implementations • 15 Nov 2016 • Gene Cheung, Weng-Tai Su, Yu Mao, Chia-Wen Lin
In response, we derive an optimal perturbation matrix $\boldsymbol{\Delta}$ - based on a fast lower-bound computation of the minimum eigenvalue of $\mathbf{L}$ via a novel application of the Haynsworth inertia additivity formula---so that $\mathbf{L} + \boldsymbol{\Delta}$ is positive semi-definite, resulting in a stable signal prior.
no code implementations • 7 Jul 2016 • Xianming Liu, Gene Cheung, Xiaolin Wu, Debin Zhao
In this paper, we combine three image priors---Laplacian prior for DCT coefficients, sparsity prior and graph-signal smoothness prior for image patches---to construct an efficient JPEG soft decoding algorithm.
no code implementations • 27 Apr 2016 • Jiahao Pang, Gene Cheung
Focusing on image denoising, we derive an optimal metric space assuming non-local self-similarity of pixel patches, leading to an optimal graph Laplacian regularizer for denoising in the discrete domain.
no code implementations • 25 Feb 2014 • Pengfei Wan, Gene Cheung, Philip A. Chou, Dinei Florencio, Cha Zhang, Oscar C. Au
In texture-plus-depth representation of a 3D scene, depth maps from different camera viewpoints are typically lossily compressed via the classical transform coding / coefficient quantization paradigm.
no code implementations • 18 Oct 2012 • Thomas Maugey, Ismael Daribo, Gene Cheung, Pascal Frossard
In this paper, we propose a novel multiview data representation that permits to satisfy bandwidth and storage constraints in an interactive multiview streaming system.