We present ATC, a C++ library for advanced Tucker-based lossy compression of dense multidimensional numerical data in a shared-memory parallel setting, based on the sequentially truncated higher-order singular value decomposition (ST-HOSVD) and bit plane truncation. Several techniques are proposed to improve speed, memory usage, error control and compression rate. First, a hybrid truncation scheme is described which combines Tucker rank truncation and TTHRESH quantization. We derive a novel expression to approximate the error of truncated Tucker decompositions in the case of core and factor perturbations. We parallelize the quantization and encoding scheme and adjust this phase to improve error control. Implementation aspects are described, such as an 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-up factors of 2.2 to 3.5 and halving memory usage. Our compressor provides precise error control, deviating only 1.4% from the requested error on average. Finally, ATC often achieves higher compression than non-Tucker-based compressors in the high-error domain.

我们介绍了 ATC，这是一个 C++ 库，用于在共享内存并行设置中基于顺序截断的高阶奇异值分解 (ST-HOSVD) 和位平面截断对密集多维数值数据进行基于 Tucker 的高级有损压缩。提出了几种技术来提高速度、内存使用、错误控制和压缩率。首先，描述了一种结合了 Tucker 等级截断和 TTHRESH 量化的混合截断方案。我们推导出一个新的表达式来近似在核心和因子扰动的情况下截断的 Tucker 分解的误差。我们并行化量化和编码方案并调整此阶段以改善错误控制。描述了实施方面，例如仅使用单个换位的 ST-HOSVD 程序。我们还讨论了 ATC 的几个可用性特性，包括存在多个接口、广泛的数据类型支持以及解压缩数据的集成下采样。数值结果表明，ATC 保持了最先进的 Tucker 压缩率，同时提供 2.2 到 3.5 的平均加速因子并将内存使用量减半。我们的压缩器提供精确的错误控制，平均仅偏离要求的错误 1.4%。最后，ATC 通常在高误差域中实现比非基于 Tucker 的压缩器更高的压缩。我们的压缩器提供精确的错误控制，平均仅偏离要求的错误 1.4%。最后，ATC 通常在高误差域中实现比非基于 Tucker 的压缩器更高的压缩。我们的压缩器提供精确的错误控制，平均仅偏离要求的错误 1.4%。最后，ATC 通常在高误差域中实现比非基于 Tucker 的压缩器更高的压缩。