Textual substitution methods, often called dictionary methods or Lempel-Ziv methods, after the important work of Lempel and Ziv, are one-dimensional compression methods that maintain a constantly changing dictionary of strings to adaptively compress a stream of characters by replacing common substrings with indices (pointers) into a dictionary. Lempel and Ziv proved that the proposed schemes were practical as well as asymptotically optimal for a general source model. Two-dimensional (i.e. images) applications of textual substitution methods have been widely studied in the past. Those applications involve first the application of a linearization strategy to the input data, and then the encoding of the resulting monodimensional vector using LZ type one-dimensional methods. More recent strategies blend textual substitution methods with Vector Quantization. In this paper we discuss the textual substitution methods for image compression, with particular attention to the AVQ class of algorithms, and review recent advances in the field.

Image compression via textual substitution

CARPENTIERI, Bruno
2009-01-01

Abstract

Textual substitution methods, often called dictionary methods or Lempel-Ziv methods, after the important work of Lempel and Ziv, are one-dimensional compression methods that maintain a constantly changing dictionary of strings to adaptively compress a stream of characters by replacing common substrings with indices (pointers) into a dictionary. Lempel and Ziv proved that the proposed schemes were practical as well as asymptotically optimal for a general source model. Two-dimensional (i.e. images) applications of textual substitution methods have been widely studied in the past. Those applications involve first the application of a linearization strategy to the input data, and then the encoding of the resulting monodimensional vector using LZ type one-dimensional methods. More recent strategies blend textual substitution methods with Vector Quantization. In this paper we discuss the textual substitution methods for image compression, with particular attention to the AVQ class of algorithms, and review recent advances in the field.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11386/3018248
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