Showing papers on "Run-length encoding published in 2013"

Simulation and Comparison of Various Lossless Data Compression Techniques based on Compression Ratio and Processing Delay

Abstract: increasing need to store data in lesser memory several lossless compression techniques are developed. This paper intends to provide the performance analysis of lossless compression techniques over various parameters like compression ratio, delay in processing, size of image etc. It provides the relevant data about variations in them as well as to describe the possible causes for it. It describes the basic lossless techniques as Huffman encoding, run length encoding, arithmetic encoding and Lempel-ziv-welch encoding briefly with their effectiveness under varying parameters. Considering the simulation results of grayscale image compression achieved in MATLAB software, it also focused to propose the possible reasons behind differences in comparison.

Compression of FPGA bitstreams using improved RLE algorithm

Abstract: FPGA are configured using bit streams often loaded from memory. FPGA often called as reconfigurable design because it lower the memory requirements, reduce the bitstreamsize. Some techniques are not suitable for real time decompression. There is need to design a compression technique which efficiently reduces bit stream size meanwhile keeping decompression ratio minimum. In our technique there are some major part of work which are more important they are 1) smart arrangements of the compressed bits that can significantly decreases the overhead of decompression engine 2) combination of bitmask-based compression and run length encoding of repetitive patterns 3)selection of profitable parameter for bit stream compression. The proposed techniques outperforms the compression ratio of existing techniques by 5–15% and decompression hardware is capable of operating at 200M H Z.

Mobile device memory compression method based on dictionary encoding and run-length encoding

Abstract: The invention discloses a mobile device memory compression method based on dictionary encoding and run-length encoding. The mobile device memory compression method based on the dictionary encoding and the run-length encoding mainly solves the problem that an existing dictionary encoding compression method and an existing run-length encoding compression method are low in compression ratio of memory data. The mobile device memory compression method based on the dictionary encoding and the run-length encoding mainly comprises the following steps of (1) reading in the memory data and the lengths of the storage data, (2) judging whether the memory data are compressible data, directly recording the lengths of the data and the data when the data are not compressible data, and using a run-length encoding compressed format to compress continuous identical character strings when the data are compressible data, (3) using a dictionary compressed format to compress other ordinary memory data, (4) judging whether compression is carried out on the tail of the memory data, stopping compressing when the compression is carried out on the tail of the memory data, and continuing reading in the memory data when the compression is not carried out on the tail of the memory data. Compared with existing other storage compression methods, the mobile device memory compression method based on the dictionary encoding and the run-length encoding is higher in compression ratio, thus more residual space can be released for an internal storage of a mobile device, operating efficiency of the mobile device can be improved, and the mobile device memory compression method based on the dictionary encoding and the run-length encoding can be used in mobile devices which need memory compression.

From Run Length Encoding to LZ78 and Back Again

Abstract: In this paper, we present efficient algorithms for interconversion between Lempel-Ziv 78 (LZ78) encoding and run length encoding (RLE). We show how, given an RLE of size n for a string S, we can compute the corresponding LZ78 encoding of size m for S in O((n + m) log σ) time, where σ is the number of distinct characters appearing in S. We also show how, given an LZ78 encoding of size m for a string S, we can compute the corresponding RLE of size n in O(n + m) time. Both algorithms use O(m) extra working space.

Direct command generation for CNC machinery based on data compression techniques

Abstract: This paper presents a direct command generation technique for digital motion control systems. In this paradigm, higher-order differences of a given trajectory (i.e. position) are calculated and the resulting sequence is compacted via data compression techniques. The overall method is capable of generating trajectory data at variable rates in forward- and reverse-directions with the utilization of a linear interpolator. As a part of the command generation scheme, the paper also proposes a new data compression technique titled @DY10. Apart from this new method, the performances of the proposed generator employing different compression algorithms (such as Huffman coding, Arithmetic coding, LZW, and run length encoding) are also evaluated through three test cases. The paper illustrates that the @DY10 technique, which is suitable for real-time hardware implementation, exhibits satisfactory performance in terms of data compaction achieved in the test cases considered.

Image compression method and device based on run-length encoding (RLE)

Abstract: The invention provides an image compression method and device based on run-length encoding (RLE). The image compression method includes that whether pixel values of adjacent pixels in an image to be compressed are identical is sequentially compared and judged, the zone bit in the pixel format is set to be the value adopting RLE and RLE is performed on yes judgment, otherwise the zone bit is set to be the value not adopting RLE and RLE is not performed; during decoding, whether RLE is adopted is judged according to the zone bit in the pixel format of a pixel to be decoded, and RLE is adopted on yes judgment; and the zone bit is the bit with the smallest color display influence caused by G in the red, green and blue (RGB) pixel format. The image compression method and device can solve the problem of the traditional RLE algorithm of data quantity increasing after coding on some conditions, reach a compression ratio larger than that of the RLE algorithm only by losing little pixel accuracy, and are simple and convenient due to the fact that only shifting and bit manipulation are adopted in the whole encoding and decoding processes.

Compression and decompression of FPGA bitstreams

Abstract: Reconfigurable system uses bitstream compression to reduce the bitstream size and the memory requirement. The communication bandwidth is improved by reducing the reconfiguration time. Existing research has explored efficient compression with slow decompression or fast decompression at the cost of compression efficiency. This paper proposes a decode-aware compression technique to improve both compression and decompression efficiencies. The three major contributions of this paper are: i) Efficient bitmask selection technique that can create a large set of matching patterns; ii) Proposes a bitmask based compression using the bitmask and dictionary selection technique that can significantly reduce the memory requirement iii) Efficient combination of bitmask-based compression and run length encoding of repetitive patterns. The original bitstream can be generated using the decompression engine.

Autocorrelations of Binary Sequences and Run Structure

Abstract: We analyze the connection between the autocorrelation of a binary sequence and its run structure given by the run length encoding. We show that both the periodic and the aperiodic autocorrelation of a binary sequence can be formulated in terms of the run structure. The run structure is given by the consecutive runs of the sequence. Let C = (C0, C1,..., Cn) denote the autocorrelation vector of a binary sequence and Δ the difference operator. We prove that the th component of Δ2(C) can be directly calculated by using the consecutive runs of total length k. In particular, this shows that the th autocorrelation is already determined by all consecutive runs of total length l <; k.In the aperiodic case, we show how the run vector can be efficiently calculated and give a characterization of skew-symmetric sequences in terms of their run length encoding.

FPGA Bit-stream Compression Using Run-length Encoding

Abstract: Reconfigurable system uses bit-stream compression to reduce the bit-stream size and the memory requirement. The communication bandwidth is improved reducing the reconfiguration time. Existing research has explored efficient compression with slow decompression or fast decompression at the cost of compression efficiency. This paper proposes a decode- aware compression technique to improve both compression and decompression efficiencies. The three major contributions of this paper are: i) Efficient bitmask selection technique that can create a large set of matching patterns; ii) Proposes a bitmask based compression using the bitmask and dictionary selection technique that can significantly reduce the memory requirement iii) Efficient combination of bitmask-based compression and run length encoding of repetitive patterns.

Drawing server, center server, encoding apparatus, control method, encoding method and program

Abstract: PROBLEM TO BE SOLVED: To perform an efficient memory check utilizing encoding processing.SOLUTION: Data to which parity information is added regarding a memory to be checked are written in the memory, the data are then read from the memory, run length encoding processing is performed thereon and encoded data are generated. An encoding apparatus refers to a bit stream regarding the written data and, when generating the encoded data, compares the bit stream with the added parity information, thereby detecting a bit inversion error.

Index Compression for Audio Fingerprinting Systems Based on Compressed Suffix Array

Abstract:  Abstract—As one of most popular technologies, audio fingerprinting has recently attracted much attention in music retrieval systems. In music retrieval methods based on audio fingerprints, a large database is required in order to compare the fingerprints extracted from the query. In other words, the efficient search method has to be developed. In this paper, we propose a method for index compression using a compressed suffix array. Taking advantage of the fact that the repetitive characters occur frequently in higher bits of the sorted audio fingerprint data, the proposed method compresses the index by encoding the 8-bit data sequences by Run Length Encoding. Vertical Code is also used to compress the array, wherein the positions of the sorted data are stored. Four sets of music databases are used in experiments to evaluate the effectiveness of the proposed method. The experimental results show that the proposed method, compared with the conventional method, only needs 30% of the space of an audio fingerprints database for a music database consisting of 8000 songs, and around 80% of the index space for a database of 1000 songs. Moreover, the entire space cost is reduced to around 60%, compared with the method based on the suffix array. using a suffix array (6) has also been proposed. In the method based on the suffix array, the space cost increases in proportion to the growing music database. In this paper, we proposed a method to reduce the space cost by compressing the index of the database. The paper is organized as follows: Section II outlines music retrieval based on audio fingerprints. We review a fast Hamming space search method (7) based on a suffix array in Section III, and propose a space-saving method based on a compressed suffix array in Section IV. We evaluate the proposed method in Section V. Finally, the conclusions and future work are given in Section VI.

A review on “A Novel Technique for Image Steganography Based on Block-DCT and Huffman Encoding”

Abstract: This paper reviews the embedding and extraction algorithm proposed by “A. Nag, S. Biswas, D. Sarkar and P. P. Sarkar” on “A Novel Technique for Image Steganography based on Block-DCT and Huffman Encoding” in “International Journal of Computer Science and Information Technology, Volume 2, Number 3, June 2010” [3] and shows that the Extraction of Secret Image is Not Possible for the algorithm proposed in [3]. 8 bit Cover Image of size is divided into non joint blocks and a two dimensional Discrete Cosine Transformation (2-D DCT) is performed on each of the blocks. Huffman Encoding is performed on an 8 bit Secret Image of size and each bit of the Huffman Encoded Bit Stream is embedded in the frequency domain by altering the LSB of the DCT coefficients of Cover Image blocks. The Huffman Encoded Bit Stream and Huffman Table

Apply Run-length encoding on pixel differences to do image hiding

Abstract: In 2011, Chen used Run Length Coding to record the repetition times of continuous data with the same value. These recorded data were then embedded in cover images by Module-based Substitution. In order to increase the quantity of repetition times of the data with the same value, in this paper, the pixel values are changed into difference values by using Median Edge Predictor (MED). The range of all possible difference values is subsequently divided into two regions. The difference values in the regions are reassigned new positive values, put through Run Length Coding, and embedded into cover images by Modulebased Substitution. According to the experimental results, the quality of the embedded image in the proposed method is better than that in Chen's method.

Drawing server, center server, encoding apparatus, control method, encoding method, program, and recording medium

Abstract: PROBLEM TO BE SOLVED: To perform an efficient memory check utilizing encoding processing.SOLUTION: Data to which parity information is added regarding a memory to be checked are written in the memory, the data are then read from the memory, run length encoding processing is performed thereon and encoded data are generated. An encoding apparatus refers to a bit stream regarding the written data and, when generating the encoded data, compares the bit stream with the added parity information to detect a bit inversion error.

Performance Analysis of Mobile Memory Optimization Techniques

Abstract: SMSLingo, a hybrid compression technique is a conjunction of RLE with static dictionary encoders based on lossless reversible transformation. This will be used for text file compression to offer better compression ratio and allow better utilization of internal memory on Android platform. The idea behind the technique is of converting the normal English text into short-form words using static dictionary and then applying Run Length Encoding (RLE) technique on this converted short-form text. Experimental results are evaluated and comparison is made between 3 text compression techniques, Huffman Coding, RLE and SMS Lingo. Promising rise is seen in the achieved results using the SMS Lingo compression algorithm in comparison with other available methods. Also this application is reasonably smaller in size as compared to the size of default SMS application present on Android platforms and with the other SMS compressor applications present for the platform. The RAM and cache memory consumption is around 3 MB for this application where the default Messaging application requires around 8 MB. Thus the proposed hybrid technique is reasonable with respect to RAM as well as cache memory consumption.

Integrating Run Length Encoding and Column oriented database execution using Binary Search Tree

Abstract: Column oriented databases have attracted significant amount of attention recently and database systems based on Column oriented technology are used extensively for analytical processing such as those found in data warehouses, decision support, and business intelligence and forecasting applications. Column oriented databases have enormous potential for data compression because of the similarity of adjacent records. This paper will discuss an algorithm that makes use of this similarity in a column oriented databases to integrate the compression and execution processes. It proposes a new indexing method called Binary Search Tree (BST) indexing that supports O (log n) insertion, deletion and look-up operations. Additionally, the paper also describes the implementation of these basic operations.

Storage Area and Temporal Based Optimized Run Length Codec For Classic JPEG Image Compression (SAT-BORL CODEC)

Abstract: This invention optimizes the entropy encoding part of JPEG (Joint Photographic Experts Group) image compression by modifying the run length encoding method that performs the actual compression by removing the redundancy from transformed and quantized image data. Using the fact that the preceding processes of run length coding, in JPEG compression algorithm, produces a large number of zeros, the original run length coding uses an ordered pair (a,b), where ‘a’ is the length of consecutive zeros preceding the ASCII character ‘b’. The proposed run length encoding scheme removes an unintended redundancy, from the original run length encoding scheme, by using an ordered pair only when a zero occurs and using the same EOB (End of Block) parameter at the end of each block. The proposed encoding scheme does not alter the value of PSNR but is found to be very effective in reducing the size of JPEG compressed image data.

Selection from plural run-length encoding methods to compress a data string

Abstract: A run-length encoding method is selected (502) from a plurality of such methods based on content of a bit string (such as a traffic indication map TIM in Smart Meter networks). Encoding parameters (such as codeword length) are also selected (504) based on the content, and the bit string is encoded (506) according to the selected method and parameters. In various non-limiting examples: different run-length encoding methods arc selected (508) based on whether the bit string has sequences of consecutive same-value bits interspersed with isolated. opposite-value bits or interspersed with sequences of consecutive opposite-value bits; the codeword length parameter is selected (510) based on how many consecutive same-value bits arc in the bit string; and encoding entails disposing a marker between code words to indicate that the codeword continues.