I recently came across OpenCV, a very exciting open source Computer Vision livrary with nifty interfaces in C++, Python, Java and Matlab.

There are a zillion tutorials on the Web, but i like the ones on LearnOpenCV so far. I spent a bit of time on one of the first ones, Blob Detection. The python stuff is great but rerunning each time you change a parameter gets old really quickly.

So I set out to do a quick JavasScript version, using OpenCV.js.

Building OpenCV.js from source is one option, butI simply went for this download link instead.

The official OpenCV.js tutorial is very useful, and so is this page to get started.

The next difficulty is that the SimpleBlobDetector function is not present in OpenCV.js… thankfully someone did a port of the C++ function in javascript. link.

Next I needed a javascript framework. Between Angular, Bootstrap, etc. it is easy to get lost. In the end, jquery and jquery-ui, without any particular framework was enough to create simple sliders so as to update parameters on the fly, which was my initial goal anyway.

The code is here and the end result is here.

Let me know your thoughts!