仿射（或一阶）光流模型有6个参数，描述图像平移，放大，旋转及剪切。类affine_optical_flow提供方法利用两帧图像序列来估计这些参数。-An affine (or first-order) optic flow model has 6 parameters, describing image translation, dilation, rotation and shear. The class affine_flow provides methods to estimates th