# A New Lossless DNA Compression Algorithm Based on A Single-Block Encoding Scheme
## 4 Conclusions  
In this paper, the authors described a new reference-free DNA compressor (DNAAC-SBE), a lossless hybrid compressor that consisted of three phases, to compress any type of DNA sequences. The obtained \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Dataset** & **Original Size (MB)** & **gzip** & **DSRC** & **Quip** & **Fqzcomp** & **GTZ** & **DNAAC-SEB** \\ \hline ERR005143\_1 & 121.92 & 1.020 & 0.238 & 0.250 & 0.227 & 0.230 & **0.219** \\ ERR005143\_2 & 121.92 & 1.086 & 0.249 & 0.239 & 0.229 & 0.230 & **0.219** \\ SRR554369\_1 & 158.11 & 0.209 & 0.250 & 0.223 & 0.222 & 0.233 & **0.220** \\ SRR554369\_2 & 158.11 & 0.209 & 0.249 & 0.227 & 0.222 & 0.234 & **0.220** \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Compression ratios of different tools on 4 FASTQ datasets. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline \multirow{2}{*}{**Dataset**} & \multirow{2}{*}{**Method**} & \multicolumn{5}{c}{**Metrics**} \\ \cline{3-6}  & & **C-Size** & **C-Mem** & **D-Mem** & **C-Time** & **D-Time** \\ \hline \multirow{5}{*}{ERR005143\_1} & DSRC & 30.46 & 166.45 & 100.56 & **5.54** & 3.4 \\  & Quip & 28.96 & 393.7 & 389.02 & 10.63 & 22.09 \\  & Fqzcomp & 27.73 & 79.46 & 67.33 & 7.88 & 10.08 \\  & Gzip & 124.36 & **0.86** & **1.39** & 28.94 & **2.7** \\  & DNAAC-SEB & **26.81** & 580.38 & 563,91 & 38.08 & 18.64 \\ \hline \multirow{5}{*}{ERR005143\_2} & DSRC & 30.41 & 168.56 & 106.5 & **5.83** & 4.09 \\  & Quip & 29.25 & 395.25 & 389.54 & 11.07 & 23.95 \\  & Fqzcomp & 27.9 & 79.46 & 59.3 & 8.45 & 10.35 \\  & Gzip & 132.42 & **0.86** & **1.39** & 29.45 & **2.79** \\  & DNAAC-SEB & **26.28** & 580.57 & 524.57 & 72.06 & 20.54 \\ \hline \multirow{5}{*}{SRR554369\_1} & DSRC & 39.52 & 183.42 & 152.65 & **4.11** & 4.46 \\  & Quip & 35.26 & 383.95 & 382.59 & 10.86 & 22.93 \\ \cline{1-1}  & Fqzcomp & 35.13 & 79.47 & 67.34 & 7.21 & 10.4 \\ \cline{1-1}  & Gzip & 45.97 & **0.87** & **1.39** & 28.51 & **1.05** \\ \cline{1-1}  & DNAAC-SEB & **34.9** & 702.18 & 615.97 & 43.71 & 31.34 \\ \hline \multirow{5}{*}{SRR554369\_2} & DSRC & 39.38 & 173.57 & 132.1 & **4.23** & 4.6 \\ \cline{1-1}  & Quip & 35.93 & 383.84 & 382.1 & 11.63 & 23.62 \\ \cline{1-1}  & Fqzcomp & 35.12 & 66.41 & 57.179 & 7.86 & 10.52 \\ \cline{1-1}  & Gzip & 45.89 & **0.87** & **1.39** & 27.98 & **1.05** \\ \cline{1-1}  & DNAAC-SEB & **34.84** & 781.98 & 644.66 & 43.18 & 30.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Comparison of compressed data size, processing time and memory utilization using FASTQ datasets. results show that DNAAC-SBE outperformed some of the state-of-the-art compressors on the benchmark performed in terms of the compression ratio, regardless of the file format or data size. The proposed algorithm compressed both repeated and non-repeated sequences, not depending on any specific patterns or parameters and accepting data from all kinds of platforms. An important achievement of the paper was that it took into consideration the appearance of an unidentified base found in DNA data sequences, ignored by most of the other compression methods. Another advantage of this approach was that the DNAAC-SBE compressor guaranteed the full recovery of the original data. The design of DNAAC-SBE was simple and flexible, showing good compression rates compared to an important part of other similar algorithms. DNAAC-SEB is more suitable when the compressed data, storage space and data transfer were crucial. More efforts will be made in the future to optimize memory utilization and compression speed. Conceptualization, D.M., X.Y. and A.S.; methodology, D.M. ; software, D.M. and A.S.; validation, D.M., X.Y. and A.S.; Data curation, D.M. ; The paper was initially drafted by [PERSON] and revised By [PERSON], X.Y. and A.S.; supervision, X.Y. ; All authors have read and agreed to the published version of the manuscript. This work was supported by WHUT (Wuhan University of Technology) university. The authors are grateful for this support. This research received no external funding.