Definition of compression ratio: difference between two commercial JPEG2000 program libraries.
The objective was to demonstrate the difference in the definition of compression ratio between two popular commercial JPEG 2000 program libraries. An institutional review board approved this study and waived informed consent. Using each of two JPEG 2000 libraries (libraries A and B), 20 abdomen computed tomography images with 12-bit depth (from scanner 1) and 20 images with 16-bit depth (from scanner 2) were compressed to three different nominal compression ratios: 10:1, 15:1, and 20:1. Achieved compression ratios (the original image file size to the compressed size) were compared with the nominal compression ratios using one-sample t-test tests. At each nominal compression level, the achieved compression ratios for scanner 1 images compressed using library A were approximately 1.33-fold greater than the nominal compression ratio (p < 0.0001), while the achieved compression ratios for the remaining three scanner-library combinations (scanner 1-library B, scanner 2-library A, and scanner 2-library B) were approximately the same as the nominal compression ratio (p-value range, 0.22-0.93). The definition of compression ratio is different between commercial JPEG 2000 program libraries. The definition should be standardized to facilitate the adoption and communication of an acceptable compression level.
Department of Radiation Applied Life Science, Seoul National University College of Medicine, Seoul, Korea.
Kil Joong
KJ
Kim
Bohyoung
B
Kim
Seung Wook
SW
Choi
Young Hoon
YH
Kim
Seokyung
S
Hahn
Tae Jung
TJ
Kim
Soon Joo
SJ
Cha
Vasundhara
V
Bajpai
Kyoung Ho
KH
Lee
D044962:Data Compression / Q000379:methods*; D006801:Humans; D011873:Radiology Information Systems; D017216:Telemedicine; D014057:Tomography, X-Ray Computed