Images compression with a DCT2 based algorithm

Project 2 for the Methods of Scientific Computation course for the MSc in Computer Science at University of Milano-Bicocca.

Brief

As described in docs/MCS_project-description.pdf, this project is divided into two parts:

• The first one aims to implement the Discrete Cosine Transform Type-II, and compare its time complexity against a library's implementation (which supposingly uses a Fast Fourier Transform behind the scenes). The comparison will be held against scipy's implementation. This part of the project and its README can be found into _PART1 folder of this repository.
• The second one is a Web App that implements a simple JPEG-derived algorithm to demonstrate how DCT2 is used in image compressions. The application has been deployed and it is available here: https://dct-image-compression.herokuapp.com/

Running locally (project part 2)

Make sure you have Python 3.7 installed locally.

$ git clone https://github.com/mferri17/dct-image-compression
$ cd dct-image-compression
$ pip install -r requirements.txt
$ python manage.py runserver 9999

If you prefer, you can also run the application using Heroku. First of all, you have to install the Heroku CLI. After pip install, you can run the application locally with this command for Linux users:

$ heroku local

Or this one for Windows users:

> heroku local web -f Procfile.windows

Your app should now be running on localhost:9999. Using the Web App, you a media folder should appear in the project root, that is where uploaded images are saved.

Deploying to Heroku

$ heroku create
$ git push heroku master
$ heroku open

or

For more information about using Python on Heroku, see these articles.

Folder Tree Structure

In docs folder you can find project description, some slides and proposed images to test the application.

This is a Django Web App. Most relevant code that directly use DCT2 algorithm is placed into webui/views.py (the component that handle browser requests) and webui/utils.py (containing the algorithm described in the project description).

Other files are needed for running a Django projects (see, for example, webui/templates for the Views and webui/urls.py for routing) and deploying it on Heroku (such as app.json and Procfile).

Authors

• Nassim Habbash (808292) - dodicin
• Marco Ferri (807130) - mferri17