Image to ASCII HTTP Service

Overview

It's a small http serivce built upon Flask, Pillow and Numpy. It converts images (png/jpg/bmp) to their ASCII version.

To use the service, user should POST their binary image file to '/upload' and the converted image will be returned as JSON.

To get a basic feeling of its function, user can go to the project folder and run the demo as (change the url if the http service is not running locally):

python demo.py

The returned result is in JSON:

{
"data":[row1, row2, ..],

"message": "Image converted.",

"status": 200
}

each row in the 'data' can be considered one row of pixels of the converted image.

The three major components for building this service are:

Flask The micro web framework, mature and perfect for "micro services"

Pillow The Python image library, very mature and the go-to choice for common image processing tasks

Numpy The Python numerical library, very mature and most powerful

There are no other dependencies for this service. However, for testing and demostration, the following tools are chosen:

Flask-testing Nice Flask testing extensions and make testing easier

Requests Very mature Python HTTP library and easy to use

Project Files

img2ascii.py The main Flask app.

img_converter.py Converter function from image to ascii

demo.py demonstration of the function

tests.py Tests

requirements.txt Python package dependencies

fruits.png and Lenna.png Two sample images for testing and demo

Build and Test

To set up the development, in the folder of the project, run:

virtualenv --python=/usr/bin/python3 env

then activate the new environment by:

source env/bin/activate

after this, install all the dependencies by run:

pip install -r requirements.txt

then it's done.

To run the app locally, you can do like this:

python img2ascii.py

To test the app, just run:

python tests.py

To test the app manually and get a demo of the function, just run:

python demo.py

or you can use your favorite command line tools such as curl or httpie to test '/upload' when the service is up. For example:

curl -i -X POST -H "Content-Type: multipart/form-data" -F "file=@fruits.png" http://localhost:8000/upload