说明：  它指的是使用计算机提取图像信息，决定每个图像的点是否属于一个图像特征。特征提取的结果是把图像上的点分为不同的子集，这些子集往往属于孤立的点、连续的曲线或者连续的区域。
(It refers to the use of computer to extract image information, decide whether each image point belongs to an image feature. The results of feature extraction is to a point on the image is divided into different subsets of these subsets, tend to be isolated point, continuous curve or continuous area. )