marisanest / image-codec

image-codec

The image-codec is a simple CLI tool to encode and decode PGM images. Among others, following methods are used:

• Variable Block Size Encoding
• Block-adaptive transform selection using Discrete Sinus Transformation (DST-VII)
• Rate-distortion optimized quantization
• Entropy coding
• Context-based adaptive binary arithmetic coding (CABAC)
• Optimized encoder control with Lagrange optimization

Dependencies

• Python 3.8

Installation

Production

To install the image-codec package for production purposes please, follow the subsequent instructions. All instructions also work for Python's and Anaconda's virtual environments.

If you want to use git clone together with pip, you can run:

> git clone https://github.com/marisanest/image-codec.git
> cd image-codec

Optionally, If you want to install a specific branch, please check out the wanted branch first:

> git checkout <branch-name>

Then install the package:

> pip install .

If you want to use pip only, you can run:

> pip install git+https://github.com/marisanest/image-codec

Optionally, If you want to install a specific branch, please run the following command:

> pip install git+https://github.com/marisanest/image-codec@<branch-name>

Development

To install the image-codec package for development purposes please, follow the subsequent instructions.

If you want to use git clone together with pip, you can run:

> git clone https://github.com/marisanest/image-codec.git
> cd image-codec

Optionally, If you want to install a specific branch, please check out the wanted branch first:

> git checkout <branch-name> 

Then install the package:

> pip install -e .[development]

Usage

For simple usage of the image-codec for image encoding run:

> image-codec encode <input-path> <output-path>

and for image decoding run:

> image-codec decode <input-path> <output-path>

For further details please run:

> image-codec --help

Usage: image-codec [OPTIONS] COMMAND [ARGS]...

  A Image Codec CLI to en- and decode images.

Options:
  --version  Show the version and exit.
  --help     Show this message and exit.

Commands:
  decode  Decode image.
  encode  Encode image.

Results

Comparing the image-codec with a classical JPEG codec using PSNR (Peak Signal-to-Noise Ratio) measurement, the following quality improvements for an example image can be observed:

License

This library is available under the MIT License.