Run-length encoding

About: Run-length encoding is a research topic. Over the lifetime, 504 publications have been published within this topic receiving 4441 citations. The topic is also known as: RLE.

New Approach in E-mail Based Text Steganography

Abstract: In this study combination of lossless compression techniques and Vigenere cipher was used in text steganography that makes use of email addresses to be the keys to reconstruct the secret message which has been embedded into the email text. After selecting the cover text that has highest repetition pattern regarding to the secret message the distance matrix was formed. The members of distance matrix were compressed by following lossless compression algorithms as in written sequence; Run Length Encoding (RLE) + Burrows Wheeler Transform (BWT) + Move to Forward (MTF) + Run Length Encoding + Arithmetic Encoding (AE). Later on Latin Square was used to form stego key 1and then Vigenere table was used to increase complexity of extracting stego key 1. Final step was to choose e-mail addresses by using stego key 1 and stego key 2to embed secret message into forward e-mail platform. The experimental results showed that proposed method has reasonable performance with high complexity.

An x-crossing preserving skeletonization algorithm

Abstract: For an image consisting of wire-like patterns, skeletonization (thinning) is often necessary as the first step towards feature extraction. But a serious problem which exists is that the intersections of the lines (X-crossings) will be elongated when applying a thinning algorithm to the image. That is, X-crossings are usually difficult to be preserved as the result of thinning. In this paper, we present a non-iterative line thinning method that preserves X-crossings of the lines in the image. The skeleton is formed by the mid-points of run-length encoding of the patterns. Line intersection areas are identified via a histogram analysis of the lengths of runs, and intersections are detected at locations where the sequences of runs merge or split.

Restructuring Compressed Texts without Explicit Decompression

Abstract: We consider the problem of {\em restructuring} compressed texts without explicit decompression. We present algorithms which allow conversions from compressed representations of a string $T$ produced by any grammar-based compression algorithm, to representations produced by several specific compression algorithms including LZ77, LZ78, run length encoding, and some grammar based compression algorithms. These are the first algorithms that achieve running times polynomial in the size of the compressed input and output representations of $T$. Since most of the representations we consider can achieve exponential compression, our algorithms are theoretically faster in the worst case, than any algorithm which first decompresses the string for the conversion.

Image data compression

Abstract: Two-dimensional blocks of line-work image data are subjected to: fractal reordering; run length encoding of the pixel values of the fractal re-ordered data, index encoding of the run length encoded pixel values; and entropy encoding of the index encoded pixel values and run lengths. This lossless, but in case of applying a quantisation step, lossy image data compression and decompression method is particularly suitable for handling image data in a printer environment, and more particularly for handling image data comprising line work data or both raster images and line work data.

Automatic image mosaicking method for high-accuracy image measuring apparatus of super-view field part

Abstract: The invention relates to an automatic image mosaicking method for a high-accuracy image measuring apparatus of a super-view field part. A template matching algorithm based on similarity measure is adopted and an index template is built through a run length encoding method to appoint pixels participating in operation, wherein the template is selected by adopting a maximal overlap region so as to contain image characteristics as much as possible, and the index template only contains pixels with edge characteristics or other pixels with obvious gray level change. The invention has the advantages that: the template is automatically determined without man-machine interaction selection, thereby enhancing the efficiency; the determined template has most image characteristics of objects to be measured; the pixels participating in the operation have obvious characteristics, and the other pixels do not participate in the operation, therefore matching accuracy is enhanced; the pixels participating in the operation, which is appointed through the index template, only occupies a great small part of the integral template, therefore operation efficiency is enhanced; the index template is built through the run length encoding method, therefore storage efficiency is high, and computer processing is convenient.