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How to differentiate between a Zeelander 44, 55 and 72?

One day, your life might depend on being able to tell the difference between a Zeelander 44, a 55 and the 72.

At first glace, these boat models are quite similar to each other. You could easily think that a Z44 is a Z55 closer to you.

To figure this out, you can spend 5 hours manually reviewing and annotating a thousands photos, deleting bad training data, and staring at tiny thumbnails photos of these boats until your eyes start bleeding.

Then, put this data into a ResNet34, and see that after all of that effort you are able to tell each model from the others 60% of the time. In other words, it guesses correctly less than every two out of three attempts.


That's crap. A waste of time and money.

Here is how you differentiate these models like a human.

The Z44 has windows in sets of two, the Z55 has windows in sets of three, the Z72 has an uneven window layout, with four large windows in the center, two at the front, and a vent at the back.

When you need to name the model of the boat…
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Project planning in a text file

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 understand how…

Selenium testing in Jenkins with an in-memory X server

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.

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 display server that implements the X11 protocol, but does not re…

Basic cell counting and segmentation in Matlab

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 of the image like this:
I = imclearborder(…

A more confusing Internet with .brand TLDs

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 approvedhas 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 $185K, wh…

Martha Graham's Google doodle is not a video, is an image (a CSS sprite)

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 the hole in the paper. Right behind the paper…

Weekend project: Book's I've read

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 the website brea…