surf方法对多组图片分类：对于多组图片，训练词库，利用词库表示图片比较每一张与其他组的相似度，依照各图片相似度累加，评判各组之间的相似关系-surf multiple sets of image classification method: For the multiple sets of pictures, training thesaurus using thesaurus compare each image represents a similarity with other grou