Light field (LF) imaging holds immense promise for applications such as post-capture refocusing and virtual reality. However, its inherent spatial-angular trade-off significantly limits both spatial and angular resolution, restricting its practicality in real-world scenarios. To address these limitations, spatial-angular super-resolution methods have been proposed to simultaneously enhance both dimensions. Yet, existing methods struggle to fully exploit the intertwined spatial-angular correlations and fail to effectively handle sparsely sampled LFs with low spatial resolution, often leading to cumulative errors during reconstruction. In this paper, we propose an Implicit and Detail-Enhanced Network (IDNet) to overcome these challenges. Our IDNet employs 3D convolution for the joint extraction of spatial and angular information, leveraging their interdependencies for more effective LF reconstruction. Additionally, we introduce an implicit detail restoration module that enhances features while encoding positional information to refine fine details. To overcome the limitations of sparse spatial and angular information on high-detail reconstruction and angular consistency in low-resolution LFs, we design a multi-representation enhancement block. This block enhances features by learning pixel differences across multiple directions in diverse representations, effectively capturing intricate details and complex correlations. Thanks to these designs, our IDNet reconstructs novel views with finer details, effectively learns occlusion relationships, and ensures geometric consistency. Experimental results on benchmark datasets demonstrate its superior quantitative and qualitative performance. The code is publicly available at https://github.com/ldyorchid/IDNet.

In this paper, we address the problem of low-light light field (LF) image enhancement, where spatial details and angular coherence are severely degraded due to noise and insufficient illumination. Existing methods often rely on local aggregation or naive view stacking, which fail to capture global illumination and long-range spatial-angular correlations. To overcome these limitations, we propose L3FMamba, a lightweight enhancement method that integrates Retinex and Atmospheric Scattering models with dark, bright, and average channel priors for robust illumination decomposition. Moreover, we incorporate a state space model to capture non-local spatial-angular dependencies, enabling effective propagation of global context across views. By combining physics-inspired priors with structured modeling, L3FMamba achieves accurate illumination correction and fine-detail preservation with minimal parameters. Experiments show that L3FMamba outperforms the state-of-the-art in quality.

Xiaohua Wang, Zhenghua Wang, Xuan Gao, Feiran Zhang, Yixin Wu, Zhibo Xu, Tianyuan Shi, Zhengyuan Wang, Shizheng Li, Qi Qian, Ruicheng Yin, Changze Lv, Xiaoqing Zheng, Xuanjing Huang. Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing. 2024.

In this work we present practical coding schemes for the problem of lossless distributed source coding for multiple sources. We consider two scenarios - the classical Slepian-Wolf case where there is no feedback from the terminal to the sources and a case where there is feedback from the terminal to the source encoders. The correlation model of interest is given by a system of linear equations, a generalization of the work of Stankovic et al. '06. We propose a transformation of correlation model and a way to determine proper decoding schedules, both of which are required to obtain the optimal sum rate. Our scheme allows us to exploit more correlations than those in the previous work. Simulation results show that the proposed coding scheme has lower sum rate than previous work in both scenarios.

Practical constructions of lossless distributed source codes (for the Slepian-Wolf problem) have been the subject of much investigation in the past decade. In particular, near-capacity achieving code designs based on LDPC codes have been presented for the case of two binary sources, with a binary-symmetric correlation. However, constructing practical codes for the case of non-binary sources with arbitrary correlation remains by and large open. From a practical perspective it is also interesting to consider coding schemes whose performance remains robust to uncertainties in the joint distribution of the sources. In this work we propose the usage of Reed-Solomon (RS) codes for the asymmetric version of this problem. We show that algebraic soft-decision decoding of RS codes can be used effectively under certain correlation structures. In addition, RS codes offer natural rate adaptivity and performance that remains constant across a family of correlation structures with the same conditional entropy. The performance of RS codes is compared with dedicated and rate adaptive multistage LDPC codes (Varodayan et al. '06), where each LDPC code is used to compress the individual bit planes. Our simulations show that in classical Slepian-Wolf scenario, RS codes outperform both dedicated and rate-adaptive LDPC codes under q-ary symmetric correlation, and are better than rate-adaptive LDPC codes in the case of sparse correlation models, where the conditional distribution of the sources has only a few dominant entries. In a feedback scenario, the performance of RS codes is comparable with both designs of LDPC codes. Our simulations also demonstrate that the performance of RS codes in the presence of inaccuracies in the joint distribution of the sources is much better as compared to multistage LDPC codes.

We propose a network-coding based scheme to protect multiple bidirectional unicast connections against adversarial errors and failures in a network. The network consists of a set of bidirectional primary path connections that carry the uncoded traffic. The end nodes of the bidirectional connections are connected by a set of shared protection paths that provide the redundancy required for protection. Such protection strategies are employed in the domain of optical networks for recovery from failures. In this work we consider the problem of simultaneous protection against adversarial errors and failures. Suppose that nepaths are corrupted by the omniscient adversary. Under our proposed protocol, the errors can be corrected at all the end nodes with 4neprotection paths. More generally, if there are neadversarial errors and nffailures, 4ne+ 2nfprotection paths are sufficient. The number of protection paths only depends on the number of errors and failures being protected against and is independent of the number of unicast connections.

This paper introduces a network coding-based protection scheme against single- and multiple-link failures. The proposed strategy ensures that in a connection, each node receives two copies of the same data unit: one copy on the working circuit and a second copy that can be extracted from linear combinations of data units transmitted on a shared protection path. This guarantees instantaneous recovery of data units upon the failure of a working circuit. The strategy can be implemented at an overlay layer, which makes its deployment simple and scalable. While the proposed strategy is similar in spirit to the work of Kamal in 2007 2010, there are significant differences. In particular, it provides protection against multiple-link failures. The new scheme is simpler, less expensive, and does not require the synchronization required by the original scheme. The sharing of the protection circuit by a number of connections is the key to the reduction of the cost of protection. This paper also conducts a comparison of the cost of the proposed scheme to the 1+1 and shared backup path protection (SBPP) strategies and establishes the benefits of our strategy.

We propose a network-coding based scheme to protect multiple bidirectional unicast connections against adversarial errors and failures in a network. The end nodes of the bidirectional connections are connected by a set of shared protection paths that provide the redundancy required for protection. Suppose that ne paths are corrupted by an omniscient, computationally unbounded adversary. Under our proposed protocol, the errors can be corrected at all the end nodes with 4neprotection paths. More generally, if there are neadversarial errors and nƒfailures, 4ne+ 2nƒprotection paths are sufficient. The number of protection paths only depends on the number of errors and failures being protected against and is independent of the number of unicast connections.

We consider the problem of rate and power allocation for a sensor network under the pairwise distributed source coding constraint. For noiseless source-terminal channels, we show that the minimum sum rate assignment can be found by finding a minimum weight arborescence in an appropriately defined directed graph. For orthogonal noisy source-terminal channels, the minimum sum power allocation can be found by finding a minimum weight matching forest in a mixed graph. Numerical results are presented for both cases showing that our solutions always outperform previously proposed solutions. The gains are considerable when source correlations are high.

We explore the problem of rate and power allocation for a sensor network where pairwise distributed source coding is employed (introduced by Roumy and Gesbert ’07). For noiseless node-terminal channels, we show that the minimum sum rate assignment with this property can be found by finding a minimum weight arborescence in an appropriately defined directed graph. For orthogonal noisy node-terminal channels, the minimum sum power allocation can be found by finding a minimum weight matching forest in a mixed graph. Numerical results are presented for the noiseless case showing that our solution outperforms previous solutions when source correlations are high.