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Xiangchu Feng

7 accepted papers

2023

Preconditioning Matters: Fast Global Convergence of Non-convex Matrix Factorization via Scaled Gradient Descent

NeurIPS 2023poster

Low-rank matrix factorization (LRMF) is a canonical problem in non-convex optimization, the objective function to be minimized is non-convex and even non-smooth, which makes the global convergence guarantee of gradient-based algorithm quite challenging. Recent work made a breakthrough on proving tha…

Cited by 15SourcePDFScholar
2020

LST-Net: Learning a Convolutional Neural Network with a Learnable Sparse Transform

ECCV 2020poster

The 2D convolutional (Conv2d) layer is the fundamental element to a deep convolutional neural network (CNN). Despite the great success of CNN, the conventional Conv2d is still limited in effectively reducing the spatial and channel-wise redundancy of features. In this paper, we propose to mitigate t…

2017

Multi-Channel Weighted Nuclear Norm Minimization for Real Color Image Denoising

ICCV 2017poster

Most of the existing denoising algorithms are developed for grayscale images. It is not trivial to extend them for color image denoising since the noise statistics in R, G, and B channels can be very different for real noisy images. In this paper, we propose a multi-channel (MC) optimization model f…

Cited by 359PDFScholar
2016

A Probabilistic Collaborative Representation Based Approach for Pattern Classification

CVPR 2016poster

Conventional representation based classifiers, ranging from the classical nearest neighbor classifier and nearest subspace classifier to the recently developed sparse representation based classifier (SRC) and collaborative representation based classifier (CRC), are essentially distance based classif…

Cited by 337PDFScholar
2015

Convolutional Sparse Coding for Image Super-Resolution

ICCV 2015poster

Sparse coding (SC) plays an important role in versatile computer vision applications such as image super-resolution (SR). Most of the previous SC based SR methods partition the image into overlapped patches, and process each patch separately. These methods, however, ignore the consistency of pixels…

Cited by 448PDFScholar
2015

Patch Group Based Nonlocal Self-Similarity Prior Learning for Image Denoising

ICCV 2015poster

Patch based image modeling has achieved a great success in low level vision such as image denoising. In particular, the use of image nonlocal self-similarity (NSS) prior, which refers to the fact that a local patch often has many nonlocal similar patches to it across the image, has significantly enh…

Cited by 472PDFScholar