A Quadsection Algorithm for Grammar-Based Image Compression
Grammar-based compression is to find a small grammar that generates a given data and has been well-studied in text compression. In this paper, we apply this methodology to compression of rectangular image data. We first define a context-free rectangular image grammar (CFRIG) by extending the context-free grammar. Then we propose a quadsection type algorithm by extending a bisection type algorithm for grammar-based compression of text data. We show that our proposed algorithm approximates in polynomial time the smallest CFRIG within a factor of O(n 4/3), where an input image data is of size O(n) ×O(n). We also present results on computational experiments on the proposed algorithm.
KeywordsBisection Context-free Rectangular Image Grammar
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