Graphics

WebGPU is and ongoing effort to make browsers even more powerful platforms. When vendors finish their work (2021/2012?), web apps will be able to leverage the awesome power of modern GPU to render graphics and do general-purpose computing through dedicated API!

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:

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.

Coordinate system in HTML5 Canvas is set up in such a way that its origin (0,0) is in the upper-left corner. This solution is nothing new in the world of screen graphics (e.g. the same goes for Windows Forms and SVG). CRT monitors, which were standard in the past, displayed picture lines from top to bottom and image within a line was created from left to right. So locating origin (0,0) in the upper-left corner was intuitive and it made creating hardware and software for handling graphics easier.

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:

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

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