README.md

pylibjpeg-libjpeg

A Python 3.8+ wrapper for Thomas Richter's libjpeg, with a focus on use as a plugin for pylibjpeg.

Linux, MacOS and Windows are all supported.

Installation

Dependencies

NumPy

Installing the current release

pip install pylibjpeg-libjpeg

Installing the development version

Make sure Python and Git are installed. For Windows, you also need to install Microsoft's C++ Build Tools.

git clone --recurse-submodules https://github.com/pydicom/pylibjpeg-libjpeg
python -m pip install pylibjpeg-libjpeg

Supported JPEG Formats

Decoding

ISO/IEC Standard	ITU Equivalent	JPEG Format
10918	T.81	JPEG
14495	T.87	JPEG-LS
18477		JPEG XT

Encoding

Encoding of JPEG images is not currently supported

Supported Transfer Syntaxes

Decoding

UID	Description
1.2.840.10008.1.2.4.50	JPEG Baseline (Process 1)
1.2.840.10008.1.2.4.51	JPEG Extended (Process 2 and 4)
1.2.840.10008.1.2.4.57	JPEG Lossless, Non-Hierarchical (Process 14)
1.2.840.10008.1.2.4.70	JPEG Lossless, Non-Hierarchical, First-Order Prediction (Process 14 [Selection Value 1])
1.2.840.10008.1.2.4.80	JPEG-LS Lossless
1.2.840.10008.1.2.4.81	JPEG-LS Lossy (Near-Lossless) Image Compression

Usage

With pylibjpeg and pydicom

from pydicom import dcmread
from pydicom.data import get_testdata_file

ds = dcmread(get_testdata_file('JPEG-LL.dcm'))
arr = ds.pixel_array

Standalone JPEG decoding

You can also decode JPEG images to a numpy ndarray:

from libjpeg import decode

with open('filename.jpg', 'rb') as f:
    # Returns a numpy array
    arr = decode(f.read())

# Or simply...
arr = decode('filename.jpg')