TRPX V2.0 data compression algorithm

January 31, 2026 · View on GitHub

This repository provides two related components:

  • HDF5 terse filter – an HDF5 plugin that compresses diffraction data using the next-generation TERSE/PROLIX (TRPX) algorithm.
  • Pyterse – a Python package that provides direct Python bindings (via pybind11) to the TERSE/PROLIX library.

Both are powered by the same TERSE/PROLIX algorithm. You can build only the HDF5 filter, only the Pyterse Python package, or both.

Pyterse python package

The pyterse python package provides Python bindings for the C++ TERSE/PROLIX(TRPX) compression algorithm scheme (https://github.com/senikm/trpx). This version of TRPX is parallel, has better memory management, and compression modes.

Prerequisites

Before using pyterse, ensure your data meets these requirements:

  • Signed or unsigned integral type data
  • Grayscale data
  • Preferably has high dynamic range

Installation

Create a virtual environment:

conda create -n pyterse python pip numpy pillow
conda activate pyterse

Install the package:

pip install pyterse

Usage guide

Basic operations

Creating a Terse object

There are multiple ways to create a Terse object:

import pyterse

# Empty constructor
terse = pyterse.Terse()

# From NumPy array
terse = pyterse.Terse(data)  # data can be nD NumPy array or slice

# With custom compression mode
terse = pyterse.Terse(data, pyterse.TerseMode.SIGNED)  # Available modes: SIGNED, UNSIGNED, SMALL_UNSIGNED, DEFAULT

Inserting and managing data

Add data to an existing Terse object:

# Append data at the end
terse.push_back(data)  # Data must match existing shape (terse.dim())

# Insert at specific position
terse.insert(pos, data)  # pos is the frame index

File operations

Save and load compressed data:

# Save to file
terse.save('filename.trpx')

# Load from file
loaded_terse = pyterse.Terse.load('filename.trpx')

Data Decompression

Decompress data:

# Decompress all data
decompressed_data = terse.prolix()

# Decompress specific frame
frame = terse.at(0)
decompressed_frame = frame.prolix()

Metadata Management

# Set metadata for a frame
terse.set_metadata(frame, "metadata string")

# Get metadata from a frame
metadata = terse.metadata(frame)

Utility Methods

# Data information
terse.dim()               # Dimensions of one frame
terse.size              # Number of elements per frame
terse.number_of_frames  # Number of frames
terse.number_of_bytes   # Size in bytes of compressed data
terse.bits_per_val      # Bits used per value
terse.is_signed         # Whether data is signed

# Data management
terse.erase(pos)          # Remove frame at position
terse.shrink_to_fit()     # Optimize memory usage

# Compression settings
terse.set_block_size(size)  # Set compression block size (before adding frames)
terse.set_fast(bool)        # Toggle fast compression mode
terse.set_small(bool)       # Toggle small data optimization
terse.dop()                 # Degree of parallelism
terse.set_dop(value)        # Set degree of parallelism (0.0 to 1.0)

# Float data compression
terse.set_fractional_precision (value)
terse.fractional_precision()

Building from source

conda create -n pyterse python pip numpy pillow
conda activate pyterse
git clone https://github.com/senikm/trpx2.0.git
cd trpx2.0
mkdir build
cd build
cmake .. -DCMAKE_PREFIX_PATH=$CONDA_PREFIX
make
python3 py_tests/pyterse_test.py  # Will run unittests

HDF5 tersecodec

Prerequisites

Before proceeding, ensure you have the following installed on your system:

  1. Create a new conda environment
conda create -n hdf5_terse_env python=3.10
conda activate hdf5_terse_env
  1. Install CMake, HDF5 and other dependencies
conda install cmake hdf5 numpy h5py hdf5plugin pillow
cmake --version
  1. Clone the repository and build the filter
git clone https://github.com/senikm/trpx2.0.git
cd trpx2.0
mkdir build
cd build
cmake .. -DCMAKE_PREFIX_PATH=$CONDA_PREFIX
make

Note: The CMakeLists.txt provided uses the CONDA_PREFIX environment variable to locate HDF5. Ensure the Conda environment is active when running CMake.

  1. Running performance tests

Run the test.py in py_tests folder.

python3 py_tests/filter_test.py

Note: The conda environment is activated and by default the script loads the filter from build/src/terse.so.

Sample output

HDF5_PLUGIN_PATH: None
h5py version: 3.12.1
HDF5 version: 1.14.3
TERSE filter registered successfully with ID 32029
TERSE filter is available.
Original data shape: (30, 512, 512)
Original data size: 30720.00 KB
Compressed HDF5 file size: 1044.42 KB
Data successfully compressed and decompressed with TERSE filter.
  1. You can make the filter path permanent
echo 'export HDF5_PLUGIN_PATH=/path/to/hdf5_filter/build/src' >> ~/.bashrc
source ~/.bashrc

Fiji/ImageJ plugin for .trpx format files

For compilation, use the Java version that came with Fiji, to ensure Java compatibility. Also make sure the ij-1.??.jar package is included in the compilation: For example, compile with:

    Applications/Fiji.app/java/macosx/zulu8.60.0.21-ca-fx-jdk8.0.322-macosx_x64/jre/Contents/Home/bin/javac -cp /Applications/Fiji.app/jars/ij-1.53t.jar TRPX_Reader.java

Then create the .jar files with:

    Applications/Fiji.app/java/macosx/zulu8.60.0.21-ca-fx-jdk8.0.322-macosx_x64/jre/Contents/Home/bin/jar -cvf Terse_Reader.jar TRPX_Reader*.class

Then copy Terse_Reader.jar to the "plugins" directory of Fiji:

    cp TRPX_Reader.jar /Applications/Fiji.app/plugins/.

Then restart Fiji, and Terse Reader is in the plugins menu.

Reading TRPX files with DIALS

Please, install Pyterse package with the following command before reading single TRPX files in DIALS:

dials.python -m pip install pyterse

Citation

If you use our software in your research, please cite our paper using the following BibTeX entry:

@article{MATINYAN2026114298,
    title = {TRPXv2.0: superfast, parallel compression of diffraction patterns and images, with native Python and HDF5 support},
    journal = {Ultramicroscopy},
    volume = {281},
    pages = {114298},
    year = {2026},
    issn = {0304-3991},
    doi = {https://doi.org/10.1016/j.ultramic.2025.114298},
    url = {https://www.sciencedirect.com/science/article/pii/S0304399125001962},
    author = {S. Matinyan and P. Filipcik and D.G. Waterman and C.D. Owen and J.P. Abrahams}
}