Interactive accuracy is directly relative to the distribution of the calibration markers in multi-touch system. This paper
describes a new calibration method of multi-touch projected display, which uses different types of markers in different
areas of the projected display screen and calculates the positions of markers with some special functions such as corner
detection and integral of bright spots. With the presented methods, the positions of markers can be calculated accurately.
Furthermore, the markers are grouped using automatic calibration method, which speeds up the calculation by almost ten
times. The methods developed in this paper can be used for linear and non-linear camera environment.