scholarly journals Enkripsi Citra Bitmap Menggunakan Algoritma Kompresi Lampel-Ziv-Welch (LZW)

2020 ◽  
Vol 4 (1) ◽  
pp. 9
Author(s):  
Sudirman Sudirman
Keyword(s):  
Compression Algorithm ◽  
Original Image ◽  
File Size ◽  
Compression Technique ◽  
Use Of Data ◽  
File Formats

<p><em>The use of data in the form of image files has become more widespread in various fields. Therefore, security of image files from unauthorized persons is important. Various techniques to reduce file size, including securing files, have been developed, one of which is compression. Compression technique becomes important in processing large images such as Bitmap images. Ziv Welch seal is a loseless compression algorithm that can compress images without any loss of pixel elements in them or the resulting compression image is identical to the original image. The image will be encrypted first and then performed the compression technique using the Ziv Welch Lempel algorithm. The resulting compression is no longer in the form of images but in the form of files with the * .mat extension. The different file formats from images to non-image files can help avoid cryptanalysis</em></p>

PERANCANGAN DAN IMPLEMENTASI ALGORITMA ELIAS GAMMA CODE UNTUK MENGKOMPRESI RECORD DATABASE PADA APLIKASI RANGKUMAN PENGETAHUAN UMUM LENGKAP

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Hikka Sartika ◽  
Taronisokhi Zebua
Keyword(s):  
Compression Ratio ◽  
General Public ◽  
Storage Capacity ◽  
Storage Space ◽  
File Size ◽  
Compression Technique ◽  
Code Algorithm ◽  
Database File ◽  
Large File

Storage space required by an application is one of the problems on smartphones. This problem can result in a waste of storage space because not all smartphones have a very large storage capacity. One application that has a large file size is the RPUL application and this application is widely accessed by students and the general public. Large file size is what often causes this application can not run effectively on smartphones. One solution that can be used to solve this problem is to compress the application file, so that the size of the storage space needed in the smartphone is much smaller. This study describes how the application of the elias gamma code algorithm as one of the compression technique algorithms to compress the RPUL application database file. This is done so that the RPUL application can run effectively on a smartphone after it is installed. Based on trials conducted on 64 bit of text as samples in this research it was found that compression based on the elias gamma code algorithm is able to compress text from a database file with a ratio of compression is 2 bits, compression ratio is 50% with a redundancy is 50%. Keywords: Compression, RPUL, Smartphone, Elias Gamma Code

scholarly journals An Approach to Efficient Dictionary Utilization and Improved Data Compression Technique for LZW Algorithm

2020 ◽  
Vol 10 (2) ◽  
pp. 224-229
Keyword(s):  
Data Compression ◽  
Conventional Method ◽  
Large Data ◽  
Compression Algorithm ◽  
Case Scenario ◽  
Compression Technique ◽  
Data Set ◽  
New Methods ◽  
Lzw Algorithm ◽  
The Way

This paper proposes an improved data compression technique compared to existing Lempel-Ziv-Welch (LZW) algorithm. LZW is a dictionary-updation based compression technique which stores elements from the data in the form of codes and uses them when those strings recur again. When the dictionary gets full, every element in the dictionary are removed in order to update dictionary with new entry. Therefore, the conventional method doesn’t consider frequently used strings and removes all the entry. This method is not an effective compression when the data to be compressed are large and when there are more frequently occurring string. This paper presents two new methods which are an improvement for the existing LZW compression algorithm. In this method, when the dictionary gets full, the elements that haven’t been used earlier are removed rather than removing every element of the dictionary which happens in the existing LZW algorithm. This is achieved by adding a flag to every element of the dictionary. Whenever an element is used the flag is set high. Thus, when the dictionary gets full, the dictionary entries where the flag was set high are kept and others are discarded. In the first method, the entries are discarded abruptly, whereas in the second method the unused elements are removed once at a time. Therefore, the second method gives enough time for the nascent elements of the dictionary. These techniques all fetch similar results when data set is small. This happens due to the fact that difference in the way they handle the dictionary when it’s full. Thus these improvements fetch better results only when a relatively large data is used. When all the three techniques' models were used to compare a data set with yields best case scenario, the compression ratios of conventional LZW is small compared to improved LZW method-1 and which in turn is small compared to improved LZW method-2.

‘Modulation’ by Richard Powers: Digital sound, compression and the short story

2021 ◽  
Vol 11 (1-2) ◽  
pp. 161-176
Author(s):  
Michael Hedges
Keyword(s):  
Data Compression ◽  
Short Story ◽  
Original Music ◽  
Richard Powers ◽  
Recording Industry ◽  
File Size ◽  
Cultural Artifact ◽  
Use Of Data ◽  
Music File ◽  
Digital Sound

This article presents a reading of ‘Modulation’ (2008) by Richard Powers. Firstly, I consider the short story’s representation of the MP3 music file, specifically its effects on how music is circulated and stored, as well as how it sounds. These changes are the result of different processes of compression. The MP3 format makes use of data compression to reduce the file size of a digital recording significantly. Such a loss of information devises new social and material relations between what remains of the original music, the recording industry from which MP3s emerged and the online markets into which they enter. I argue that ‘Modulation’ is a powerful evocation of a watershed moment in how we consume digital sound: what Jonathan Sterne has termed the rise of the MP3 as ‘cultural artifact’. I contend that the short story, like the MP3, is also a compressed manner of representation. I use narrative theory and short story criticism to substantiate this claim, before positioning ‘Modulation’ alongside Powers’s novels of information. I conclude by suggesting that ‘Modulation’ offers an alternative to representing information through an excess of data. This article reads Powers’s compressed prose as a formal iteration of the data compression the story narrates.

scholarly journals A Compression Algorithm for DNA Palindrome Compression Technique

2020 ◽  
Vol 32 ◽  
pp. 03006
Author(s):  
D. Suneetha ◽  
D. Rathna Kishore ◽  
P. Narendra Babu
Keyword(s):  
Compression Algorithm ◽  
Experimental Result ◽  
Compression Process ◽  
Compression Technique ◽  
Plain Text ◽  
Security Issues ◽  
Cipher Text ◽  
Different Types ◽  
Dna Palindrome ◽  
Better Than

Data Compression in Cryptography is one of the interesting research topic. The compression process reduces the amount of transferring data as well as storage space which in turn effects the usage of bandwidth. Further, when a plain text is converted to cipher text, the length of the cipher text becomes large. This adds up to tremendous information storing. It is extremely important to address the storage capacity issue along with the security issues of exponentially developing information. This problem can be resolved by compressing the ciphertext based on a some compression algorithm. In this proposed work used the compression technique called palindrome compression technique. The compression ratio of the proposed method is better than the standard method for both colored and gray scaled images. An experimental result for the proposed methods is better than existing methods for different types of image.

scholarly journals CitySAC: A Query-Able CityGML Compression System

Smart Cities ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 106-117
Author(s):  
Chengxi Siew ◽  
Pankaj Kumar
Keyword(s):  
Data Storage ◽  
Spatial Data ◽  
City Planning ◽  
Data Transfer ◽  
Original Data ◽  
File Size ◽  
Compression Technique ◽  
3D Data ◽  
Data Infrastructures ◽  
Data Efficiency

Spatial Data Infrastructures (SDIs) are frequently used to exchange 2D & 3D data, in areas such as city planning, disaster management, urban navigation and many more. City Geography Mark-up Language (CityGML), an Open Geospatial Consortium (OGC) standard has been developed for the storage and exchange of 3D city models. Due to its encoding in XML based format, the data transfer efficiency is reduced which leads to data storage issues. The use of CityGML for analysis purposes is limited due to its inefficiency in terms of file size and bandwidth consumption. This paper introduces XML based compression technique and elaborates how data efficiency can be achieved with the use of schema-aware encoder. We particularly present CityGML Schema Aware Compressor (CitySAC), which is a compression approach for CityGML data transaction within SDI framework. Our test results show that the encoding system produces smaller file size in comparison with existing state-of-the-art compression methods. The encoding process significantly reduces the file size up to 7–10% of the original data.

scholarly journals USE OF NEW EFFICIENT LOSSLESS DATA COMPRESSION METHOD IN TRANSMITTING ENCRYPTED BAPTISTA SYMMETRIC CHAOTIC CRYPTOSYSTEM DATA

2016 ◽  
Vol 78 (6-4) ◽  
Author(s):  
Muhamad Azlan Daud ◽  
Muhammad Rezal Kamel Ariffin ◽  
S. Kularajasingam ◽  
Che Haziqah Che Hussin ◽  
Nurliyana Juhan ◽  
...  
Keyword(s):  
Data Compression ◽  
Data Transmission ◽  
Compression Algorithm ◽  
Huffman Coding ◽  
Compression Method ◽  
Compression Technique ◽  
Chaotic Dynamical System ◽  
Fast Encoding ◽  
Compression Mechanism ◽  
Lossless Data Compression

A new compression algorithm used to ensure a modified Baptista symmetric cryptosystem which is based on a chaotic dynamical system to be applicable is proposed. The Baptista symmetric cryptosystem able to produce various ciphers responding to the same message input. This modified Baptista type cryptosystem suffers from message expansion that goes against the conventional methodology of a symmetric cryptosystem. A new lossless data compression algorithm based on theideas from the Huffman coding for data transmission is proposed.This new compression mechanism does not face the problem of mapping elements from a domain which is much larger than its range.Our new algorithm circumvent this problem via a pre-defined codeword list.  The purposed algorithm has fast encoding and decoding mechanism and proven analytically to be a lossless data compression technique.

scholarly journals IMPLEMENTATION OF CRYPTOGRAPHY AND STEGANOGRAPHY FOR TEXT ON COVER IMAGE USING AES AND F5 ALGORITHM

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Ratna Astuti Nugrahaeni ◽  
R. Rumani M. R. Rumani M. ◽  
Surya Michrandi Nasution
Keyword(s):  
Cover Image ◽  
Security Level ◽  
Original Image ◽  
File Size ◽  
Stego Image ◽  
Size Change ◽  
Avalanche Effect ◽  
Aes Algorithm ◽  
Significant Difference

This journal explains about implementation that combine both cryptography and steganography method for texton cover image to increase the security level. Text will be encrypted with AES algorithm, and then it will be embedded to the cover image using F5 algorithm. The implemented AES algorithm has a good performance, with Avalanche Effect value ranges from 0.43 � 0.59. The resulting image, or stego image, has a very similar histogram with the original image, so there is no significant difference between the two of them. However, the file size change about 1.25 � 3.25 times larger than theoriginal image. If noise or disruption is given to stego image, the information can not be extracted.Keywords: cryptography, steganography, AES, F5

scholarly journals Content and Privacy Protection in JPEG Images by Reversible Visual Transformation

2020 ◽  
Vol 10 (19) ◽  
pp. 6776
Author(s):  
Xin Cao ◽  
Yuxuan Huang ◽  
Hao-Tian Wu ◽  
Yiu-ming Cheung
Keyword(s):  
Cloud Computing ◽  
Privacy Protection ◽  
Location Information ◽  
File Format ◽  
Original Image ◽  
Secret Key ◽  
File Size ◽  
Jpeg Images ◽  
Encryption Schemes ◽  
Dc Coefficient

With the popularity of cloud computing and social networks, more and more JPEG images are stored and distributed. Consequently, how to protect privacy and content in JPEG images has become an important issue. Although traditional encryption schemes can be employed, the file format of JPEG images is changed so that their usage may be affected. In this paper, a reversible visual transformation algorithm is proposed to protect content in JPEG images. Specifically, the DC coefficient in each user-selected block is modified, while the information required to recover it is reversibly hidden into AC coefficients. Then the signs of AC coefficients in the selected blocks are flipped and the blocks are further scrambled with a secret key. By embedding the location information of the selected blocks in a transformed image, the original image can be exactly recovered when needed. Besides, regions to be protected can be arbitrarily chosen without substantially affecting the rest of the image. The experimental results on a set of JPEG images validate the efficacy and reversibility of the proposed algorithm. In addition, good performance is achieved in terms of invisibility of the protected content, image quality, file size preservation and security.

scholarly journals mzMLb: a future-proof raw mass spectrometry data format based on standards-compliant mzML and optimized for speed and storage requirements

2020 ◽  
Author(s):  
Ranjeet S. Bhamber ◽  
Andris Jankevics ◽  
Eric W Deutsch ◽  
Andrew R Jones ◽  
Andrew W Dowsey
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometry Data ◽  
File Size ◽  
Data Format ◽  
File Access ◽  
Data Interchange ◽  
File Formats ◽  
Reference Implementation ◽  
And Storage ◽  
Access Efficiency

AbstractWith ever-increasing amounts of data produced by mass spectrometry (MS) proteomics and metabolomics, and the sheer volume of samples now analyzed, the need for a common open format possessing both file size efficiency and faster read/write speeds has become paramount to drive the next generation of data analysis pipelines. The Proteomics Standards Initiative (PSI) has established a clear and precise XML representation for data interchange, mzML, receiving substantial uptake; nevertheless, storage and file access efficiency has not been the main focus. We propose an HDF5 file format ‘mzMLb’ that is optimised for both read/write speed and storage of the raw mass spectrometry data. We provide extensive validation of write speed, random read speed and storage size, demonstrating a flexible format that with or without compression is faster than all existing approaches in virtually all cases, while with compression, is comparable in size to proprietary vendor file formats. Since our approach uniquely preserves the XML encoding of the metadata, the format implicitly supports future versions of mzML and is straightforward to implement: mzMLb’s design adheres to both HDF5 and NetCDF4 standard implementations, which allows it to be easily utilised by third parties due to their widespread programming language support. A reference implementation within the established ProteoWizard toolkit is provided.

scholarly journals Implementasi Algoritma J-Bit Encoding Pada Kompresi File PDF

2020 ◽  
Vol 1 (3) ◽  
pp. 278
Author(s):  
Frida Effelyanti Naibaho
Keyword(s):  
Compression Algorithm ◽  
File Format ◽  
Compression Technique ◽  
Compression Algorithms ◽  
Encoding Method

Compression is a reduction in the size of the data to a smaller size than the original. The technique of compression is to replace the repetitive character with a certain pattern so that the data can minimize its size. Therefore the data that will be stored needs to be compressed first so that the size becomes smaller. The advantage of pdf files is that the pdf file format can not only store data in text form but also can save an image (image) or photo. In storing in pdf files, the data that will be stored is not susceptible to viruses. One pdf file compression technique that can compress images well is compressing pdf files using the J-Bit Encoding method. J-Bit Encoding (JBE) is an algorithm that optimizes input for other compression algorithms, thus the compression algorithm will be better if it is combined with the J-Bit Encoding method.

Sign in / Sign up

Export Citation Format

Share Document