{"title":"Lightweight Spectral Super-Resolution Network for Hyperspectral Image Compression","authors":"Wei Zhang;Pengpeng Yu;Yueru Chen;Dingquan Li;Wen Gao","doi":"10.1109/LSP.2025.3576177","DOIUrl":"https://doi.org/10.1109/LSP.2025.3576177","url":null,"abstract":"The growing use of hyperspectral images demands efficient compression techniques to handle their extensive spectral data. However, current methods are constrained by their inability to adapt to high bit depth and effectively utilize the spectral characteristics, leading to suboptimal compression ratios. This paper presents a novel hyperspectral compression framework that employs a lightweight spectral super-resolution network to address these limitations. The proposed approach divides the hyperspectral image into two sub-images, comprising two distinct groups of bands: a base image consisting of anchor bands and a supplementary image comprising non-anchor bands. The base image is compressed losslessly using a conventional codec, thereby ensuring the preservation of essential information. In contrast, the supplementary image is compressed efficiently by overfitting a lightweight super-resolution network to predict the non-anchor bands during encoding. The optimized network parameters are encoded as side information to ensure high-quality spectral super-resolution during decoding. Experimental results on the ARAD hyperspectral image dataset demonstrate that our approach significantly outperforms state-of-the-art methods, effectively meeting the demand for efficient hyperspectral image compression while maintaining acceptable processing speeds.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"2339-2343"},"PeriodicalIF":3.2,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamic Fusion for Generating High-Quality Labels in Low-Light Image Enhancement","authors":"Zhuo-Ming Du;Hong-An Li;Fei-long Han","doi":"10.1109/LSP.2025.3575608","DOIUrl":"https://doi.org/10.1109/LSP.2025.3575608","url":null,"abstract":"Generating high-quality labels is crucial for self-supervised learning in low-light conditions, where traditional enhancement methods often struggle to balance detail enhancement and color fidelity. This paper presents a traditional image fusion approach that dynamically combines Multi-Scale Retinex (MSR) and Adaptive Histogram Equalization (AHE) outputs with the original image using an adaptive weighting strategy. The primary goal is not to compete with state-of-the-art deep learning-based enhancement methods but to produce intermediate images that can serve as effective labels for training self-supervised models without requiring ground-truth datasets. By dynamically fusing MSR and AHE outputs with the original image using adaptive brightness and color weights, the method improves structural integrity while enhancing brightness and color consistency. Experiments on standard low-light datasets demonstrate significant improvements in PSNR and SSIM compared to traditional enhancement methods. However, a visual analysis of the generated labels reveals differences in color saturation when compared to ground truth, providing insights into designing a suitable loss function for future self-supervised learning applications. It is important to note that this work does not include experiments or methods related to self-supervised learning itself; instead, it focuses on preparing high-quality labels for such approaches. Additionally, our method strikes a balance between computational efficiency and visual quality, making it suitable for real-time applications and paving the way for more robust and versatile learning frameworks.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"2324-2328"},"PeriodicalIF":3.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Video Complicated-Information Extraction and Filtering Network for Weakly-Supervised Temporal Action Localization","authors":"Jiaxuan Li;Tiancheng Ma;Xiaohui Yang;Lijun Yang;Chen Zheng","doi":"10.1109/LSP.2025.3575626","DOIUrl":"https://doi.org/10.1109/LSP.2025.3575626","url":null,"abstract":"Weakly-supervised temporal action localiza- tion aims to identify action instances using only video-level labels, and localize the action position in untrimmed videos. Due to the temporal continuity of video data, most methods that use single scale convolution kernel cannot model against the characterization of video data effectively, and lead to a decrease in accuracy. However, simply using multi-scale features can introduce redundant information and noise, reducing model efficiency while also affecting the accurate judgement of the model during training process. To alleviate this problem, a video complicated-information extraction and filtering network (VCEF-Net) is proposed. It contains two main modules. The first multi-scale feature extraction module is developed to enrich the information that model received. The second pseudo-label filtering module inhibits redundant information interference. VCEF-Net introduces these two modules for achieving a better utilization of video information. Experiments tested on THUMOS14 and ActivityNet1.2 demonstrate better performances of the proposed VCEF-Net and validate its effectiveness.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"2334-2338"},"PeriodicalIF":3.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sequential Number-Theoretic Optimization for High-Dimensional Channel Equalization in Coherent Optical PDM Systems","authors":"Shuai Liu;Yangfan Xu;Xinwei Du","doi":"10.1109/LSP.2025.3575611","DOIUrl":"https://doi.org/10.1109/LSP.2025.3575611","url":null,"abstract":"Polarization-division multiplexing (PDM) in coherent optical communications enhances system capacity but is vulnerable to various channel distortions including transmitter and receiver in-phase/quadrature (IQ) mismatch, rotation of state of polarization (RSOP), frequency offset (FO) and phase noise (PN), which significantly degrade the system performance. To address these challenges, we propose a novel approach using sequential number-theoretic optimization (SNTO) for the joint estimation of these distortions. We further introduce a decision-aided scheme with a window-split structure to accurately track and compensate for time-varying RSOP and PN, thereby implementing signal detection. Through comprehensive mean squared error (MSE) and bit error rate (BER) analysis under different signal-to-noise ratio (SNR) conditions and varying RSOP speeds, our method demonstrates high precision and effectiveness. The SNTO-based algorithm maintains robust performance with superior estimation accuracy and resilience against ultra-fast RSOP. This work introduces an innovative solution for high-dimensional channel equalization in coherent optical PDM systems with not only effectiveness but also robustness.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"2329-2333"},"PeriodicalIF":3.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Event-Triggered Hybrid Consensus Filter for Distributed Extended Object Tracking","authors":"Runyan Lyu;Yunze Cai;Lixiu Yao","doi":"10.1109/LSP.2025.3565369","DOIUrl":"https://doi.org/10.1109/LSP.2025.3565369","url":null,"abstract":"Motivated by the unique state characteristics of the extended object and energy constraints in distributed sensor networks, this letter proposes a novel event-triggered hybrid consensus filter for distributed extended object tracking, achieving balanced estimation-communication performance. This parallel consensus mechanism processes three consensus operations on the prior information pair, novel information pair of kinematic state, and shape parameter information pair of extent state, enabling enhanced consensus and propagation of extended object characteristics across the network. To reduce data transmission while preserving estimation performance, the proposed event-triggered strategy contains three distinct transmission tests, performed in parallel on corresponding information pairs to evaluate information loss. Simulation results of demonstrate the superior performance of the proposed filter compared with conventional triggered filters.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"2070-2074"},"PeriodicalIF":3.2,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lei Li;Yunfei Zheng;Zhongyuan Guo;Guobing Qian;Shiyuan Wang
{"title":"Steady-State Performance Analysis of the Nearest Kronecker Product Decomposition Based LMS Adaptive Algorithm","authors":"Lei Li;Yunfei Zheng;Zhongyuan Guo;Guobing Qian;Shiyuan Wang","doi":"10.1109/LSP.2025.3565395","DOIUrl":"https://doi.org/10.1109/LSP.2025.3565395","url":null,"abstract":"Inorder to address issues, such as convergence rate, stability, and computational complexity caused by the identification of long length impulse response systems, an effective nearest Kronecker product (NKP) decomposition strategy has been introduced and extended to various adaptive filters in recent years. However, the theoretical performance of the NKP decomposition-based adaptive filtering algorithms has not been thoroughly analyzed in these studies. In this letter, we focus on analyzing the steady-state performance of the NKP-based least mean square (NKP-LMS) algorithm and presents the theoretical upper bound of the step-size. Finally, simulation results confirm the precision of the theoretical assessment of the NKP-LMS algorithm and highlight its benefits in low-rank system identification.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1995-1999"},"PeriodicalIF":3.2,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Energy-Concentrated Transform for Improved Time-Frequency Representation of Seismic Signals","authors":"Siyuan Wang;Ying Hu;Hui Chen;Xuping Chen","doi":"10.1109/LSP.2025.3565164","DOIUrl":"https://doi.org/10.1109/LSP.2025.3565164","url":null,"abstract":"Time-frequency (TF) analysis is a useful tool for seismic signal processing, where reliably representing the signal's TF distribution is essential for geological interpretation. However, the traditional short-time Fourier transform (STFT) offers an ambiguous TF representation. While synchroextracting methods improve TF localization, they distort the time-width and bandwidth of seismic signals, which are crucial for applications. To address this issue, we propose a novel TF analysis method, the energy-concentrated transform (ECT), aimed at enhancing TF localization while preserving the essential time-width and bandwidth features of seismic signals. First, we analyze the limitations of the STFT and synchroextracting methods. Next, we introduce an energy suppression operator that concentrates STFT's diffused spectral energy, aligning it with the signal's intrinsic time-width and bandwidth. Additionally, an energy recovery operator is proposed to ensure the consistency of spectral energy with the STFT spectrum. Numerical examples demonstrate the effectiveness of the ECT in enhancing TF localization, improving noise immunity, and preserving critical TF features, making it a promising tool for TF representation in seismic signals.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"2084-2088"},"PeriodicalIF":3.2,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dual Space Representation Learning for Skeleton-Based Action Recognition","authors":"Yuheng Yang;Haipeng Chen;Zhenguang Liu;Sihao Hu;Yingying Jiao","doi":"10.1109/LSP.2025.3564883","DOIUrl":"https://doi.org/10.1109/LSP.2025.3564883","url":null,"abstract":"Skeleton-based action recognition is crucial for machine intelligence. Current methods generally learn from 3D articulated motion sequences in the straightforward Euclidean space. Yet, the <italic>vanilla</i> Euclidean space may not be the optimal choice for modeling the intricate correlations among human body joints. This challenge arises from the non-Euclidean nature of human anatomy, where joint correlations often vary non-linearly during movement. To address this, we propose a dual space representation learning method. Specifically, we represent the motion sequences in Hyperbolic space, leveraging its intrinsic properties to capture the non-Euclidean latent anatomy of human motions. We then incorporate the motion features from both Hyperbolic and Euclidean spaces, allowing us to precisely model the non-linear joint correlations while effectively sketching human poses. The proposed method empirically achieves state-of-the-art performance on the NTU RGB+D 60, NTURGB+D 120, and NW-UCLA datasets.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"2104-2108"},"PeriodicalIF":3.2,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"DOA Estimation for Coherent and Non-Coherent Mixed Signals Using Toeplitz Diagonal Diffusion","authors":"Wenlong Wang;Lei Zhang","doi":"10.1109/LSP.2025.3565163","DOIUrl":"https://doi.org/10.1109/LSP.2025.3565163","url":null,"abstract":"This letter introduces a new direction-of-arrival (DOA) estimation approach for mixed coherent and uncorrelated signals. The technique extracts cross-diagonal elements from the covariance matrix to form Toeplitz matrices, then averages them using a counting matrix to effectively decorrelate signals. This provides more accurate covariance estimates for subsequent subspace-based DOA estimation methods. Compared to existing approaches, the proposed method offers more degrees of freedom (DOFs) and lower computational complexity, while robustly detecting the directions of mixed coherent and uncorrelated signals under low signal-to-noise ratio (SNR) and limited snapshot conditions.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1985-1989"},"PeriodicalIF":3.2,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Non-Asymptotic Analysis on the Additional Bias of Capon's Method","authors":"Jian Dong;Jinzhi Xiang;Wei Cui;Yulong Liu","doi":"10.1109/LSP.2025.3565131","DOIUrl":"https://doi.org/10.1109/LSP.2025.3565131","url":null,"abstract":"The Capon method is one of the classical direction-of-arrival (DOA) estimation methods in array signal processing. The standard analysis of the additional bias of this method is asymptotic, which assumes the number of snapshots <inline-formula><tex-math>$K$</tex-math></inline-formula> goes to infinity. This paper provides a non-asymptotic analysis for the additional bias by employing some tools from high-dimensional probability and perturbation analysis of optimization problems. We establish upper bounds for the additional bias in both expectation and tail forms, which reveal that the additional bias has an error rate of <inline-formula><tex-math>$O(K^{-frac{1}{2}})$</tex-math></inline-formula> when the number of snapshots satisfies a certain condition. We demonstrate our results by some numerical experiments.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1980-1984"},"PeriodicalIF":3.2,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}