ATC swMATH ID: 39352 Software Authors: Wouter Baert, Nick Vannieuwenhoven Description: ATC: an Advanced Tucker Compression library for multidimensional data. We present ATC, a C++ library for advanced Tucker-based compression of multidimensional numerical data, based on the sequentially truncated higher-order singular value decomposition (ST-HOSVD) and bit plane truncation. Several techniques are proposed to improve compression rate, speed, memory usage and error control. First, a hybrid truncation scheme is described which combines Tucker rank truncation and TTHRESH quantization [Ballester-Ripoll et al., IEEE Trans. Visual. Comput. Graph., 2020]. We derive a novel expression to approximate the error of truncated Tucker decompositions in the case of core and factor perturbations. Furthermore, a Householder-reflector-based approach is proposed to compress the orthogonal Tucker factors. Certain key improvements to the quantization procedure are also discussed. Moreover, particular implementation aspects are described, such as ST-HOSVD procedure using only a single transposition. We also discuss several usability features of ATC, including the presence of multiple interfaces, extensive data type support and integrated downsampling of the decompressed data. Numerical results show that ATC maintains state-of-the-art Tucker compression rates, while providing average speed-ups of 2.6-3.6 and halving memory usage. Furthermore, our compressor provides precise error control, only deviating 1.4 Homepage: https://arxiv.org/abs/2107.01384 Source Code: https://gitlab.kuleuven.be/u0118878/atc Keywords: arXiv_cs.MS; ATC; Advanced Tucker Compression; multidimensional data; C++ library; Tensors; Tucker decomposition; ST-HOSVD; bit plane truncation Related Software: FFmpeg; HPTT; Eigen; Draco; zlib; FFTW; Zstandard; tthresh Cited in: 0 Publications Standard Articles 1 Publication describing the Software Year ATC: an Advanced Tucker Compression library for multidimensional data Wouter Baert, Nick Vannieuwenhoven 2021