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Given a string S over an alphabet of size σ, we consider practical implementations of extended compressed RAM on S, which supports access, replace, insert, and delete operations on S while maintaining S in compressed form. In this paper, we proposed two implementations where each of them is based on the compressed RAM of Jansson et al. [ICALP 2012], and Grossi et al. [ICALP 2013], respectively. Experimental results show that our implementations support the operations efficiently while keeping the space proportional to the entropy of the input during the updates.

In this paper, we propose a novel approach to succinct coding of permutations taking advantage of the “divide-and-conquer” strategy. In addition, we provide a theoretical analysis of the proposed approach leading to formulations allowing to calculate precise bounds (minimum, average, maximum) to the length of permutation coding expressed in a number of bits per permutation element for various sizes of permutations n being integer powers of 2.

Data collection and sharing have a tremendous impact on technology, business and society. Correspondingly, it brings in significant privacy and communication concerns. To this end, we present a hierarchical privacy-preserving and communication-efficient compression scheme via compressed sensing (CS) to address these two issues. In the encoding stage, the

The variable-length Reverse Multi-Delimiter (RMD) codes are known to represent sequences of unbounded and unordered integers. When applied to data compression, they combine a good compression ratio with fast decoding. In this paper, we investigate another property of RMD-codes - the ability of direct access to codewords in the encoded bitstream. We present the method allowing us to extract and decode a codeword from an RMD-bitstream in almost constant time with the tiny space overhead, and make experiments on its application to natural language text compression.

We present a joint design of sound zone control filters and robust audio coding for wireless low frequency sound zones. The audio signal is filtered using sound zone control filters and encoded using a multiple-description coder. The control filters and the multiple-description coder are combined in a nested loop. The inner loop performs filtering for sound zone control and generates multiple descriptions using oversampling and closed-loop prediction. The outer loop performs noise shaping and guarantees a trade-off between robustness and quality of the descriptions.

With the rapid development of 3D vision applications such as autonomous driving and the dramatic increase of point cloud data, it becomes critical to efficiently compress 3D point clouds. Recently, point-based point cloud compression has attracted great attention due to its superior performance at low bit rates. However, lacking an efficient way to represent the local geometric correlation well, most existing methods can hardly extract fine local features accurately. Thus it’s difficult for them to obtain high-quality reconstruction of local geometry of point clouds.

The semantic information obtained from large-scale computation in image compression is not practical. To solve this problem, we propose an Attention Aggregation Mechanism (AAM) for learning-based image compression, which is able to aggregate attention map from multiple scales and facilitate information embedding.