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

Processing multiple frames

Till now we saw examples of modification and drawing video frames just like single images. Deeper processing should involve analysis of the several frames.

If we compare two successive frames, we can find the direction and velocity of motion for each frame pixel. Such a vector field is called optical flow. It has many uses in video, graphics, and computer vision. Optical flow computation is a nontrivial task of computer vision, and we will learn to do it in Chapter 9, Computer Vision with OpenCV.

Another idea is to bufferize a number of frames and then draw parts of the frames in different parts of the screen. The famous video effect called slit-scan or time displacement is based on this principle. In effect, horizontal lines of the resulting image are built from horizontal lines of several successive frames. Often, bottom lines are taken from older frames, and top lines are made from the newest frames. So if the object was moved horizontally in the original video...