Affiliations: [a] Kulliyyah of Information and Communications Technology, Department of Computer Science, International Islamic University Malaysia, Kuala Lumpur, Malaysia
| [b] Department of Computer Science, College of Computer, Qassim University, Buraydah, Saudi Arabia
| [c] BIND Research Group, College of Computer, Qassim University, Buraydah, Saudi Arabia
Correspondence:
[*]
Corresponding author. Kamal Al-Khayyat, Kulliyyah of Information and Communications Technology, Department of Computer Science, International Islamic University Malaysia, Kuala Lumpur, Malaysia. E-mail: kamal_amk@yahoo.com.
Abstract: This paper details the examination of a particular case of data compression, where the compression algorithm removes the redundancy from data, which occurs when edge-based compression algorithms compress (previously compressed) pixelated images. The newly created redundancy can be removed using another round of compression. This work utilized the JPEG-LS as an example of an edge-based compression algorithm for compressing pixelated images. The output of this process was subjected to another round of compression using a more robust but slower compressor (PAQ8f). The compression ratio of the second compression was, on average, 18%, which is high for random data. The results of the second compression were superior to the lossy JPEG. Under the used data set, lossy JPEG needs to sacrifice 10% on average to realize nearly total lossless compression ratios of the two-successive compressions. To generalize the results, fast general-purpose compression algorithms (7z, bz2, and Gzip) were used too.
Keywords: Data compression, lossless, lossy, Pixelated images, PAQ8f
