Then we go to details of the ideas of compression algorithms based on IFS theory, such as range block search, fixed threshold, adaptive threshold, linear classification, and so on.

• 这些算法包括：全局分块搜索算法、固定门限法、自适应门限法、线性分类法、四分之一块灰度排列法和基于块合并的压缩算法。