Ideas, thoughts and solutions

Whenever you work on a project it is important to be able to plan it ahead of time. This holds true for small and big project, from planning a trip to the spa to building a spaceship. The small project plans can be maintained in you thoughts while bigger ones require tools to help you see the big-picture of the project and manage task at a lower level. There are projects which start with a fully prepared plan and projects which pivot overnight, thus invalidating any original plan. For the latter flexibility is very important, and tools like Trello offer a great solution because they can be adjusted to fit your project. However, it may happen sometimes that the project starts adjusting to the tool or that you still want to maintain a bigger picture of the main points of the project. You may also need to produce a rough development schedule to serve as a long term road-map. I have prototyped a tool (and defined a workflow) which allows you to plan such projects. To better understa...

This articles explains how to setup integration testing of web applications (that require a browser instance) on a Jenkins server. The article assumes you are able to understand the title. If you need a reminder follow the links below. Automated browser testing (source: Jeremy Keith ) What is Selenium? Read here. What is Jenkins? Read here. What is an X server? Read here. If you are still puzzled, this article is not for you. Integration testing of web application is more complicated than unit testing, because they require a browser instance to be running. In order to run a browser (such as Firefox) you need and X server. The testing server usually doesn't have one. One solution to this is to run the browser instance on another machine through VNC. This has the advantage of not using the same resources as the testing server. However it requires setting up a new machine, and configuring the integration tests to run a browser in it. Another solution is to use Xvfb, a...

Counting cells manually is a tedious error prone process for humans. Given a large data set of microscopy images this task can be achieved much faster by means of basic computer vision techniques. In this tutorial we will segment cells from an image following a method similar to the one presented by Yongming Chen in 1999. The method uses basic morphological operations  and the watershed algorithm to segment the cells. Nowadays better methods for cell segmentation exist. This method was chosen for its simplicity and ease of implementation. We start with an image of cell-like structures by Anna-Katerina Hadjantonakis and Virginia E Papaioannou . A = imread('cells.jpg'); We convert the image to grayscale: I = rgb2gray(A); To be able to extract the dimmer cells, it is necessary to perform some local contrast adjustments I = adapthisteq(I); Objects on the borders can be caused by noise and other artifacts. We can eliminate objects on the borders...

A few months ago, I wrote a post proposing to remove top level domains from the internet, as many people don't understand why we need TLDs. At the time I didn't know either. Removing TLDs would simplify browsing an possibly increase security by reducing phishing sites that make use of URL similarity to gain visits to potentially dangerous websites, or sites filled with ads. The ICANN, the body that manages Internet names, has for years been preparing something different but that produces a slightly similar effect than removing TLDs: allowing brands to register their own TLDs . The proposal may soon be approved has been approved . Brands would therefore be able to register their own TLDs. Google could register .google a potentially powerful TLD for their services, like Google Maps: maps.google instead of maps.google.com. Brand TLD don't improve short urls like google.com, but seem to be effective for use in subdomains. Registering a .<brand-name> TLD will cost...

Today's Google doodle is featuring Martha Graham, an American modern dancer. The new doodle looks like a movie, but in fact it is only a CSS sprite. The sprite is this one:  You may be wondering how is the animation/movie appearance achieved if it only uses this static image?  The technique involves CSS sprites. A sprite is a composition of several images grouped together in order to reduce the number of required HTTP request to the server. This way a website with 50 images requires only one request for the large image composition. The entire doodle involves only one sprite, which speeds up loading a lot (compared to loading each frame separately). Google has used this technique to leverage data transfer from the servers and consequently make the animation load faster than a traditional video clip.  So how is this sprite converted to an animation? Pretend you are looking through pierced piece of paper, so that you can only look through th...

It's been months since I wanted to learn databases and create a dynamic website, but it's only this weekend that I acted. In two day I learned how to use MySQL with PHP in websites and created a small project that I call "Books I've read" that stores a list of books I read (obviously). I am an avid reader and I've been storing the list of books I read (and want to read) in a text document for about a year. Finally, my project moved this list to the cloud and allows me to add, edit and update entries. The app has user authentication, so no one except me can alter my book list. The design was made in a hurry, but is good enough for my needs. Instead of using normal CSS for styling I've used LESS CSS, a dynamic stylesheet language that extends CSS with dynamic behavior, nested rules, mixins and logical operators. LESS CSS has made styling faster, but unfortunately it relies on Javascript. Without Javascript activated the website breaks. And t...