pyguetzli 1.0.5

Python bindings for Google's Guetzli, a JPEG encoder that optimises JPEG compression

PyGuetzli is a Python binding for Google’s Guetzli library.

Description of Guetzli from official’s repo:

Guetzli is a JPEG encoder that aims for excellent compression density at high visual quality. Guetzli-generated images are typically 20-30% smaller than images of equivalent quality generated by libjpeg. Guetzli generates only sequential (nonprogressive) JPEGs due to faster decompression speeds they offer.

Building and Installing PyGuetzli

In order to build Guetzli, GCC and GNU Make are required. On Debian / Ubuntu, this can be installed with the following command:

sudo apt-get install build-essential

Installing from PYPI

To install PyGuetzli from the PYPI package, just run the following command:

pip install pyguetzli

Installing from source

To build and install PyGuetzli from source, clone the repository, and run the pip install command from the project’s root directory:

git clone https://github.com/wanadev/pyguetzli.git
cd pyguetzli
pip install .

Using PyGuetzli

Example:

import pyguetzli

input_jpeg = open("./test/image.jpg", "rb").read()
optimized_jpeg = pyguetzli.process_jpeg_bytes(input_jpeg)

output = open("./optimized.jpg", "wb")
output.write(optimized_jpeg)

For more information, please visit the project’s documentation:

• http://wanadev.github.io/pyguetzli/

Trouble Shooting

Errors About Undeclared “nullptr” When Installing / Building PyGuetzli

Guetzli is written in C++ 11, so you can encounter errors when trying to compile PyGuetzli with GCC < 6.0:

...

build/temp.linux-x86_64-2.7/pyguetzli._guetzli.cpp: In function ‘int guetzli_process_rgb_bytes(char*, int, int, char**, int)’:

build/temp.linux-x86_64-2.7/pyguetzli._guetzli.cpp:474:21: error: ‘nullptr’ was not declared in this scope

     Process(params, nullptr, inData, width, height, &outData);

                     ^

error: command 'gcc' failed with exit status 1

To compile PyGuetzli using older GCC version, you can set the following environment variable:

CPPFLAGS="--std=c++11"

See issue #1 for more information.

Hacking

Running Tests

pip install tox
tox

By default test will run in Python 2.7, 3.5 and 3.6. To run only on a specific Python version run the following commands:

tox -e py27
tox -e py35
tox -e py36

Generating Documentation

From a virtualenv:

pip install -r requirements.txt
python setup.py build_sphinx

Changelog

• 1.0.5: Adds optimization flags when compiling Guetzli

• 1.0.4: MS Windows support

• 1.0.3: Updates Guetzli library

• 1.0.2: PIL Images: fixes crash with non RGB/RGBA images (grayscale, indexed,…)

• 1.0.1: Adds --std=c++11 flag when building Guetzli

• 1.0.0:

  • New and simpler API

  • Built-in function to deal with PIL / Pillow Images

  • Documentation (Sphinx)

  • Guetzli update

• 0.9.0: Initial release