1. 刚体变换与非刚体变换
What is a non-rigid transformation?
刚体变换(rigid transformation)一般分为如下几种:
- 平移对象,而不改变形状和大小;
- 镜像(reflection),左右颠倒;
- 旋转(rotation),沿着任意方向的旋转;
非刚体变换:描述的是对几何物体大小而非形状的改变。
也即:
- 刚体变换:shift or reflection(A rigid transformation preserves all distances and angle measures (and depending on your taste, orientation too),刚体变换能够继续保持物体中各点的距离和角度)
- 非刚体变换:stretching or shrinking