DPCM-DP-EN: a lossless dynamic compress and encrypted encode method for DNA storage of medical images with high storage density.

The need for long-term storage of medical images poses a challenge for healthcare organizations, and DNA is anticipated to offer a solution for it. This study proposes an effective DNA storage method (DPCM-DP-EN) for storing medical images, which comprises two key components: (i) In the compress stage, the redundancy between pixels is removed using the differential pulse code modulation (DPCM) method, followed by the use of the ZigZag and the dynamic programming (DP) for further compress; (ii) In the encode stage, a new encrypted (EN)) encode mapping method is proposed to satisfy the biological constraints while ensuring a short time and high density of encode. Tested on three distinct medical image datasets, the results indicate that the DPCM-DP-EN method achieves a compress rate of 40% and above, exceeding other methods by at least 30%. All sequences encoded by DPCM-DP-EN adhere to the GC content and homopolymer constraints, with an encode density of more than 3 bits/nt, significantly surpassing that of other encode methods, and without an impact on the processing time. Additionally, DPCM-DP-EN employs pixel coding, enabling to decode with information lossy at high error rates. In conclusion, the DPCM-DP-EN method provides a viable solution for large-scale storage of medical images (200).