Image Beyond the Screen

6Projection Mapping and Automatic Calibration: Beyond a Technique

6.1. Introduction

Today, tracking technologies make it possible to track objects moving on stage by adapting the projected video content, while operating automatic calibration techniques (calibration of the video projectors). These technologies culminate in a new approach in terms of application: projection mapping (or video mapping) is not just a technique, but a media format, a new medium for spatialized entertainment. This type of projection is used when projecting a complex surface onto an object, a façade, a 3D or relief structure. The difference between projection mapping and a standard projection is anamorphosis: the projection screen is not flat, and the projection must therefore be deformed accordingly; this process consists in correcting distortions on the different parts of the image by means of different deformations and geometric curves.

6.2. Towards a new projection dynamic

Interactive projection mapping is when the projection is modified in real-time following a particular event. This can be the effect of an external device: a mobile phone connected to the server on which the projection mapping software operates, a tablet, or even an infrared camera. On/off switches can also be considered, but this is more of a reactive than an interactive system.

Tracking is a technique that allows us to follow, by dynamic projection methods, a moving object: it means that the machine interprets and deducts ...