.NET Framework

Part 1 introduced you to OpenCV and its Emgu CV wrapper library plus showed the easiest way to create Emgu project in Visual Studio 2017. Part 2 was all about grabbing frames from video file. The third (and last) episode focuses on image transformations and contour detection…

In Part 1 you have learned what OpenCV is, what is the role of Emgu CV wrapper and how to create a Visual Studio 2017 C# project that utilizes the two libraries. In this part I will show you how to loop through frames captured from video file. Check the first part to watch demo video and find information about sample project (all the interesting stuff is inside Program.cs - keep this file opened in separate tab as its fragments will be shown in this post)…

Emgu CV is a .NET wrapper for OpenCV (Open Source Computer Vision Library) which is a collection of over 2500 algorithms focused on real-time image processing and machine learning. OpenCV lets you write software for:

Back in 2013, when I was using SVN, I wrote the post about creating a TortoiseSVN pre-commit hook that can prevent someone from committing code which is not meant to be shared (e. g. some hack done for troubleshooting). The idea was to mark “uncommittable” code with a comment containing NOT_FOR_REPO text and block the commit if such text is found in any of the modified or added files… The technique saved me a few times and proved to be useful to others…

Java and C# are very similar languages so if you have to switch between the two it’s easy to overlook subtle differences. One of the tricky bits is the meaning of protected access modifier.

Last five posts (1, 2, 3, 4, 5) were all about fun stuff with Arduino. Now it’s time for something more mundane ;) In this post I will show you how to create TeamCity build that automatically sets version information in all assemblies produced by ASP.NET application. It’s nothing new but I hope to give you some useful background info and note a few gotchas you may face…

Time for the third episode of “Out of Boredom” series :) There was a Sonar project and something about shooting paintballs… This time you will learn how to use Arduino and .NET 4.5 to receive input from joystick and use it to control servos that move a webcam horizontally and vertically!

My first Arduino based project was Sonar with C#, JS and HTML5. Now I continue the “Out of Boredom” series with a setup that allows firing a paintball marker (gun) with a command sent from a computer :) This time software stack is simpler - just a small Arduino sketch and uncomplicated WinForms (.NET/C#) application, but hardware requires a bit of electronics knowledge. Don’t worry though, nothing too complicated - I’m definitely not an expert in this field…

Part 1 described the general idea behind Sonar project, hardware components used and Arduino sketch… This second post in “Out of Boredom” series is about C# and JavaScript programs that make it possible to display ultrasonic range sensor data in web browsers. The role of .NET application is to receive messages from Arduino over serial port and broadcast it to clients using SignalR library. JS/HTML5 clients use jquery.signalR lib to obtain information about servo position with distance to obstacles and use this data to render sonar image on canvas:

This post marks the beginning of “Out of Boredom” series. It will be about creating stuff with my recently purchased Arduino Uno. Let’s have a break from chores of professional programming and create something just for fun :)

Read the first part of the article if you haven’t done so already. Part 1 has a brief overview of what GC is and how it performs its magic. It contains a test of GC performance with regards to large array of bytes. You can also find there a detailed information about my test environment…

.NET GC is very fast! Well… I hope you need more than this reassuring statement, if so, read on :) I will show you some test results to prove that I’m not lying but first I will give you a quick reminder about what GC is:

Recently I needed to acquire some database. Unfortunately it was published only as a website that presented 50 records per single page. Whole database had more than 150 thousand records. What to do in such situation? Click through 3000 pages, manually collecting data in a text file? One week and it’s done! ;) Better to write a program (so called scraper) which will do the work for you. The program has to do three things:

Recently, I wanted to extract calls to external system from log files and do some LINQ to XML processing on obtained data. Here’s a sample log line (simplified, real log was way more complicated but it doesn’t matter for this post):

Bitmap class has GetPixel and SetPixel methods that let you acquire and change color of chosen pixels. Those methods are very easy to use but are also extremely slow. My previous post gives detailed explanation on the topic, click here if you are interested.

Take a look at the following code and think what value will be displayed on the console (note that string is a reference type)?

Have you ever seen BadImageFormatException or “An attempt was made to load a program with an incorrect format” message?

Bitmap class provides two simple methods: GetPixel and SetPixel used respectively to retrieve a point of image (as the Color structure) and set a point of image. The following code illustrates how to retrieve/set all the pixels in the bitmap:

String type (System.String) stores text values as a sequence of char (System.Char) elements that represent Unicode characters (encoded in UTF-16). Usually one char element stands for one symbol.

Sorry, this post is not yet available in English. See Polish version.