Book Image

Mastering openFrameworks: Creative Coding Demystified

By : Denis Perevalov
Book Image

Mastering openFrameworks: Creative Coding Demystified

By: Denis Perevalov

Overview of this book

openFrameworks is a powerful programming toolkit and library designed to assist the creative process through simplicity and intuitiveness. It's a very handy software library written in C++ to reduce the software development process, helping you to kick-start creative coding. With the help of C++ and shaders support, openFrameworks allows for the processing of all kinds of media information with your custom-developed algorithms at the lowest possible level, with the fastest speed. "Mastering openFrameworks: Creative Coding Demystified" will introduce you to a world of creative coding projects, including interactive installations, audio-visual, and sound art projects. You will learn how to make your own projects using openFrameworks. This book focuses on low-level data processing, which allows you to create really unique and cutting-edge installations and projects. "Mastering openFrameworks: Creative Coding Demystified" provides a complete introduction to openFrameworks, including installation, core capabilities, and addons. Advanced topics like shaders, computer vision, and depth cameras are also covered. We start off by discussing the basic topics such as image and video loading, rendering and processing, playing sound samples, and synthesizing new sounds. We then move on to cover 3D graphics, computer vision, and depth cameras. You will also learn a number of advanced topics such as video mapping, interactive floors and walls, video morphing, networking, and using geometry shaders. You will learn everything you need to know in order to create your own projects; create projects of all levels, ranging from simple creative-code experiments, to big interactive systems consisting of a number of computers, depth cameras, and projectors.
Table of Contents (22 chapters)
Mastering openFrameworks: Creative Coding Demystified
About the Author
About the Reviewers

Geometrical transformations of images

Here we consider the different kinds of geometrical transformations that change the position of the image's pixel. OpenCV does operations such as image resizing and warping using interpolation that suppress the aliasing effect. Hence, using OpenCV operations is more preferable than custom pixel-by-pixel implementation, except when you implement your own transformation algorithm with antialiasing (which can be tricky), or maybe when you need the aliasing effect. The following is a list of geometrical transformations that are applicable to ofxCv images:

  • The resize( w, h ) function changes the image size to w × h pixels. For example:

    image2 = image;
    image2.resize( image2.width * 0.5, image2.height * 0.5 );

    This code transforms image to image2 with a size that equals 50 percent of the size of image. Such a procedure decreases the number of pixels four times, so the speed of processing increases 4 times. However, object localization accuracy in x and y axes...