Flying memes

Archive for the ‘Algoritmi’ Category

In Browser Real Time Object Detection From an HTTP Live Stream

Friday, July 2nd, 2021

This experiment combines hsl.js and tensorflow.js to perform real time object detection from a browser. When the mouse hovers the canvas the entire stream is shown, with the detected object framed in a black box, otherwise only the parts of the stream corresponding to detected objects are displayed.


Plotting the characteristic polynomial of a matrix

Wednesday, June 28th, 2017

Next step is determining the roots of the characteristic polynomial of a matrix. Before working on extracting the roots using Newton’s method I wanted to be able to visualize the function.


Determinant of a matrix in JS

Saturday, June 10th, 2017

I’m currently reading Deep Learning, from Ian Goodfellow, Yoshua Bengio and Aaron Courville. While reading I got interested in calculating the determinant of a square matrix, I know there are many existing libraries to do that but the algorithm looked simply enough to give it a try.


How to render a dynamic animated Delaunay triangulation

Sunday, May 4th, 2014

A friend of mine recently asked if I can create an animation out of this nice example; the first thing I did was wrap the render function around a requestAnimationFrame and add a random speed factor to all the vertices at every iteration.


Angular.js prevent an invalid form submission

Saturday, March 1st, 2014

Angular.js does an excellent job on preventing a form submission when invalid but only if the action attribute is not present, otherwise we have to implement a few tricks to achieve the same behaviour.


Useless bu fun: Encoding video to CSS

Thursday, March 14th, 2013

I spent part of the last weekend on this experiment that startet with a question: it is possible to convert a video to a stream of CSS properties ? Surprisingly the answer is yes. We can dump each video frame to a canvas and then create a special (and very long) multiple background property (one background for each video row) where each pixel is created using a 1px size gradient.


Migrating a single site of a wordpress multisite instance

Sunday, October 28th, 2012

Recently I had to deal with a WordPress multisite instance, the task was moving the contents of one of the sites hosted on the network to a local copy, update them and the re-move them to the production server.


Handling thousands of pics from a mobile device

Sunday, November 27th, 2011

Lately I’ve been involved into a fascinating project called PepperTweet which consist in extract and visualize streams of pics from twitter starting from some search keywords.


HTML5 Augmented Reality: fuzzy results

Thursday, May 12th, 2011

I spent a few hours trying to figure out how to deal with the brand new deviceorientation API in order to obtain a nice Augmented Reality effect. First I searched on how to convert Euler Angles to Cartesian Coordinates and I found a nice article about that, then I downloaded the very nice Sylvester library which lets you compute matrix operations in Javascript.


I’ve just checked in at WC2010 Johannesburg Stadium from home

Saturday, June 12th, 2010

Thanks to Uncle Pear suggestion I realized that you can easily check-in in every Foursquare venue simply invoking its id using the API, to try this behavior I checked in at Johannesburg  WC2010 stadium from my home in Italy.