Test searching by closest color in Flask / Postgres.

Closest colors are calculated and sorted using the various Delta E (CIE Lab) color difference formulae.

By default, this app uses two Delta E formulae (the 1976 and the 2000 version) that are implemented as custom Postgres SQL functions. It can also be switched to use the python-colormath implementations, for baseline comparison of accuracy and performance.

Here's a demo of the app in action.

I've asked for help with improving the performance of the Delta E CIE 2000 SQL function on StackOverflow - suggestions welcome!

First, set your app's secret key as an environment variable. For example, add the following to .bashrc or .bash_profile.

export COLORSEARCHTEST_SECRET='something-really-secret'

Then run the following commands to bootstrap your environment.

git clone https://github.com/Jaza/colorsearchtest
cd colorsearchtest
pip install -r requirements/dev.txt
python manage.py server

You will see a pretty welcome screen.

You can have a different random secret key each time the app starts, if you want:

export COLORSEARCHTEST_SECRET=`python -c "import os; from binascii import hexlify; print(hexlify(os.urandom(24)))"`; python manage.py server

You can specify DB config when the app starts:

export COLORSEARCHTEST_DATABASE_URI="postgresql://colorsearchtest:colorsearchtest@localhost:5432/colorsearchtest"; python manage.py server

Once you have installed your DBMS, run the following if necessary (shouldn't be necessary), to set up the migrations:

python manage.py db init
python manage.py db migrate

Then, run the following to create your app's database tables and perform the initial migration:

python manage.py db upgrade
python manage.py server

To actually use colorsearchtest, you need to create a set of random colors in the database. To do this, run the following command, specifying a minimum and maximum number of colors to generate (of your choice), e.g:

python manage.py createcolors 900 1000

You can re-run this whenever you like. Each time you re-run it, the script will delete all existing colors and save new ones.

By default, the Delta E formulae to use are configured as follows:

IS_DELTA_E_COLORMATH_ENABLED = False
IS_DELTA_E_DBQUERY_ENABLED = True

These can be toggled by editing the colorsearchtest/settings.py file.

In your production environment, make sure the COLORSEARCHTEST_ENV environment variable is set to "prod".

To open the interactive shell, run :

python manage.py shell

By default, you will have access to app and db.

To run all tests, run :

python manage.py test

Whenever a database migration needs to be made. Run the following commands: :

python manage.py db migrate

This will generate a new migration script. Then run: :

python manage.py db upgrade

To apply the migration.

For a full migration command reference, run python manage.py db --help.