pyjpegls

library1.5.1pypypi✓ verified 82d ago

Python wrapper for the CharLS C++ library, providing JPEG-LS lossless and near-lossless image compression. Current version 1.5.1, requires Python >=3.9. Active development with occasional releases.

serialization data

pip install pyjpegls

github ↗package ↗docs ↗

INSTALL

IMPORT

SIG · PYJPEGLS

pyjpegls

serializationpythonv1.5.1

Install

3.8s avg

Import

—

Disk

95MB

Pass rate

5/ 10

Env Coverage5 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.5.1 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

build_error

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 3.8s · import 0.000s · 93MB

95MB installed

● package 95MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

encode

✓ from jpeg_ls import encode

✗ from pyjpegls import encode

decode

✓ from jpeg_ls import decode

✗ from pyjpegls import decode

CharLS

✓ from jpeg_ls import CharLS

✗ from pyjpegls import CharLS

Encode and decode a grayscale image with default lossless settings.

import numpy as np from pyjpegls import encode, decode, ImageFormat, InterleaveMode # Create a sample 8-bit grayscale image (height, width) image = np.random.randint(0, 256, size=(256, 256), dtype=np.uint8) # Encode (lossless by default) encoded = encode(image, interleave_mode=InterleaveMode.NONE) print(f"Encoded size: {len(encoded)} bytes") # Decode back decoded = decode(encoded) print(f"Decoded shape: {decoded.shape}, dtype: {decoded.dtype}") # Verify lossless reconstruction assert np.array_equal(image, decoded), "Lossless check failed"

Debug

Known issues

gotchaThe library expects numpy arrays in (height, width) order, not (width, height). Misordered dimensions can cause silent incorrect encoding or runtime errors.

fix

Ensure your numpy array shape is (height, width, channels) for color or (height, width) for grayscale.

affects: all

gotchaSupported input dtypes are uint8, int16, and uint16 only (including signed/unsigned). Using other dtypes (e.g., float32) will raise a ValueError.

fix

Cast your array to one of the supported types before encoding: image.astype(np.uint8) or np.int16 or np.uint16.

affects: all

gotchaFor color (multi-plane) images, the array should be in (height, width, planes) order and must use InterleaveMode.SAMPLE (pixel interleaved) or InterleaveMode.LINE (line interleaved). InterleaveMode.NONE is for single-plane grayscale only.

fix

For RGB images: ensure shape is (H, W, 3) and use InterleaveMode.SAMPLE.

affects: all

gotchaThe decode function returns a numpy array; it does not return a PIL Image or any other object. Converting to PIL requires explicit conversion.

fix

Use Image.fromarray(decoded) if you need a PIL Image (after appropriate mode/format conversion).

affects: all

Upgrade

Version history

1.5.1latest on PyPI · released Oct 28, 2024

Audit

Dependencies

No dependency data recorded yet.

Agent activity

16 hits · last 30 days

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Resources

githubhttps://github.com/pydicom/pyjpegls ↗

packagehttps://pypi.org/project/pyjpegls/ ↗

docshttps://pydicom.github.io/pydicom ↗