This is a book that introduces visual SLAM, and it is probably the first Chinese book to focus on visual SLAM.
So, what is SLAM?
SLAM stands for Simultaneous Localization and Mapping, It usually refers to a robot or a moving rigid body, equipped with a specific sensor, estimates its own motion and builds a model (some kinds of description) of the surrounding environment, without a priori information [Davison2007]. If the sensor here is mainly for the camera, it is called "visual SLAM".
Visual SLAM is the subject of this book. We deliberately put a lot of definitions into a sentence, so that readers have a more clear concept. First of all, SLAM aims to solve the "positioning" and "map building" issues at the same time. In other words, it is a problem of how to estimate the location of the sensor itself, while estimate the establishment of the surrounding environment. So how to solve it? This requires a good understanding about the sensor information. The sensor can observe the external world in a certain form, but the approach of such observations is different. And, why is this question worthwhile to spend the whole contents of a book to discuss it? Because it is difficult, especially if we want to make SLAM in real time and without any prior knowledge. When we talk about visual SLAM, what we have to do is to estimate the trajectory and map based on a set of continuous images (they form a video).
This seems to be a very intuitive question. When we humans go into a strange environment, aren't we doing exactly the same thing? So, can we write programs and make the computer do it?
[Davison2007].