Amar Mukherjee

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David Wheeler and Mike Burrows introduced the Burrows-Wheeler Transform (BWT) as a practical method of data compression in 1994. The elegant simplicity of the BWT has captivated researchers for the past decade. The BWT is simple yet powerful. Other lossless compression techniques are a lot more cumbersome, making it difficult to assess their efficiency.(More)
We consider real-time rendering of dynamic glossy objects with realistic shadows under distant all-frequency environment lighting. Previous PRT approaches pre-compute light transport for a fixed scene and cannot account for cast shadows on high-glossy objects occluded by dynamic neighbors. In this paper, we extend double/triple product integral to(More)
In this paper we discuss the use of a text preprocessing algorithm that can improve the compression ratio of standard data compression algorithms, in particular `bzip2', when used on text les, by up to 20%. The text preprocessing algorithm uses a static dictionary of the English language that is kept separately from the compressed le. The method in which(More)
We investigate off-line dictionary oriented approaches to DNA sequence compression, based on the Burrows-Wheeler Transform (BWT). The preponderance of short repeating patterns is an important phenomenon in biological sequences. Here, we propose off-line methods to compress DNA sequences that exploit the different repetition structures inherent in such(More)
This paper explores two techniques for on-line exact pattern matching in files that have been compressed using the Burrows-Wheeler transform. We investigate two approaches. The first is an application of the Boyer-Moore algorithm (Boyer & Moore 1977) to a transformed string. The second approach is based on the observation that the transform effectively(More)
In this paper, we present a new algorithm for text compression. The basic idea of our algorithm is to define a unique encryption or signature of each word in the dict.ionary by replacing certain characters in the words by a special character ‘*’ and retaining a few characters so that the word is still retrievable. For any encrypted text the most frequently(More)