fpzip is a library and command-line utility for lossless and optionally lossy compression of 2D and 3D floating-point arrays. fpzip assumes spatially correlated scalar-valued data, such as regularly sampled continuous functions, and is not suitable for compressing unstructured streams of floating-point numbers. In lossy mode, fpzip discards some number of least significant mantissa bits and losslessly compresses the result. fpzip currently supports IEEE-754 single (32-bit) and double (64-bit) precision floating-point data. fpzip is written in C++ but has a C compatible API that can be called from C and other languages. It conforms to the C++98 and C89 language standards.

fpzip is released as Open Source under a three-clause BSD license. Please see the file LICENSE for further details.

fpzip was developed for Linux and macOS but can be built on Windows using CMake. To use CMake, type:

cd fpzip
mkdir build
cd build
cmake ..
cmake --build . --config Release

fpzip can be configured using compile-time options, e.g.:

cmake .. -DFPZIP_FP=FPZIP_FP_SAFE -DBUILD_UTILITIES=OFF

To display the available options, type:

cmake .. -L

Basic regression testing is available:

ctest -V -C Release

fpzip may also be built using GNU make:

cd fpzip
gmake

This builds lib/libfpzip.a and bin/fpzip.

The GNU make options are listed in the file Config and should preferably be set on the command line, e.g.:

gmake FPZIP_FP=FPZIP_FP_SAFE BUILD_UTILITIES=0

To run the regression tests, type:

gmake test

Documentation is currently limited to the source files themselves. For information on the API, please see the header file include/fpzip.h. For an example of how to call fpzip, please see the source file utils/fpzip.cpp. This utility may be used to compress binary files of raw floating-point numbers. Usage is given by:

fpzip -h

fpzip was written by Peter Lindstrom at Lawrence Livermore National Laboratory.

If you use fpzip for scholarly research, please cite the following paper:

Peter Lindstrom and Martin Isenburg
"Fast and Efficient Compression of Floating-Point Data"
IEEE Transactions on Visualization and Computer Graphics, 12(5):1245-1250, 2006

fpzip is distributed under the terms of the BSD license. See the files LICENSE and NOTICE for details.

SPDX-License-Identifier: BSD

LLNL-CODE-764017

For questions and comments, please contact us at fpzip@llnl.gov. Please submit bug reports and feature requests via the GitHub issue tracker.