Bioleptic

Fast, lossy wavelet compression for physiological signals — ECG, PPG, and accelerometry — with Rust, Python, and JavaScript/WebAssembly bindings.

Bioleptic is a biosignal compression library that shrinks physiological time-series data — electrocardiogram (ECG), photoplethysmogram (PPG), and accelerometer streams — at high compression ratios with low reconstruction error (PRD). It combines a multi-level discrete wavelet transform (DWT) with scalar quantization and adaptive entropy coding, and runs natively in Rust or from Python (NumPy) and the browser (WebAssembly). That makes it a good fit for wearables, remote patient monitoring, medical-device storage, and large physiological datasets where bandwidth and disk are tight.

Features

• Wavelet-based — CDF 9/7, CDF 5/3, Daubechies-4, and Symlet-4 transforms
• Tunable rate–distortion — pick a quantization scale (or an explicit multiplier) to trade size against fidelity for a target PRD
• Multiple entropy coders — Deflate, an adaptive binary rANS, and a significance-map coefficient model
• Float32 and Float64 input — f64 is downcast to f32 internally
• Cross-platform — one core, with Rust, Python/NumPy, and JavaScript/WASM frontends
• Lightweight & dependency-light — small footprint, suitable for embedded and edge use

Algorithm

1. Non-finite substitution (NaN → 0, ±inf → 0/1)
2. Mean-centering + range normalization
3. Multi-level DWT (CDF 9/7, CDF 5/3, Daubechies-4, or Symlet-4; depth scales with signal length)
4. Quantization to i16 with a configurable scale
5. Detail-coefficient thresholding
6. Entropy coding (Deflate, adaptive rANS, or a significance-map coefficient model)

Installation & Usage

Rust

cargo add bioleptic

let compressed = compress(&signal, CompressionOptions::default())?;
let recovered  = decompress(&compressed)?;

Python

pip install bioleptic-py

from bioleptic import compress_signal, decompress_signal, CompressionOptions

compressed = compress_signal(signal, CompressionOptions("cdf97", 11, "low"))
recovered  = decompress_signal(compressed)

JavaScript

npm install bioleptic-js

import {
    CompressionMethod,
    CompressionOptions,
    CutoffLevel,
    QuantizationScale,
    compressSignal,
    decompressSignal
} from "bioleptic-js";

const signal = new Float32Array([1.0, 2.0, 3.0, 4.0, 5.0, 1.0, 2.0, 3.0, 4.0, 5.0, 1.0, 2.0, 3.0, 4.0, 5.0]);

const options = new CompressionOptions(
    CompressionMethod.Cdf97,
    QuantizationScale.S11,
    CutoffLevel.Low,
);

const compressed = compressSignal(signal, options);  // Uint8Array
const recovered = decompressSignal(compressed);       // Float32Array
console.info("Recovered signal", recovered);

License

This project is licensed under either of

• BSD-3-Clause License (see LICENSE)
• Apache License, Version 2.0 (see LICENSE)

at your option.