Bernstein Polynomial and B´ezier-Bernstein Spline - Bezier and Splines in Image Processing and Machine Vision - page 22

(a) regular point (b) inflection point

(d) cusp of second kind

(c) cusp of first kind

Fig. 1.10. Classification of different G-images:(a) regular point; (b) inflection point;
(c) cusp of first kind; (d) cusp of second kind.

1.6 Regeneration Technique

Below we depict two different methods of regeneration of a contour from its
approximate information. These regenerations of arcs and line segments are
simple and straightforward, and are helpful in data reduction.

1.6.1 Method 1

Method 1 considers only two points, namely E and C (Figure 1.7) of the
characteristic triangle for the regeneration of an arc when the starting point
A is known beforehand. D is the point of intersection of the horizontal line
through A , and the line through E and parallel to AC . So, one can easily get
the Bezier characteristic triangle and regenerate the arc. If the GE between
two key pixels is found to be a straight line, then it is generated by the
Bresenham algorithm as already mentioned.