Color vision test

Summary

I created an online color blindness for EnChroma that achieved #1 organic ranking on Google for "color blind test" for over ten years, bringing in millions of search visitors. It is currently available on https://enchroma.com/test.

I wrote the test in Javascript using HTML5 Canvas and PhoneGap. PhoneGap (now Apache Cordova) can run the same code base as a standalone web page, or can package and deliver the code base as an app through iOS and Android app stores. 

The test can operate in 9-AFC "number" mode or a kid-friendly 3-AFC mode using primitive shapes: square, circle, and diamond.

My back-end algorithm used Bayesian Adaptive Estimation to measure the subject's just-noticeable-difference thresholds in color space. Unlike staircase tests that only move up or down by fixed step sizes, the Bayesian method selects the following test condition that maximizes the expected change in posterior entropy.

Skills

Javascript
HTML5 Canvas
PhoneGap (Android/iOS App)
Circle Packing  Algorithms
Color Theory, Color Perception
Bayesian Statistics