Miaou Shaou-Gang, Ke Fu-Sheng, Chen Shu-Ching
Electronic Engineering Department, Chung-Yuan Christian University, Chung-Li 32023, Taiwan.
IEEE Trans Inf Technol Biomed. 2009 Sep;13(5):818-21. doi: 10.1109/TITB.2009.2022971. Epub 2009 May 15.
Hospitals and medical centers produce an enormous amount of digital medical images every day, especially in the form of image sequences, which requires considerable storage space. One solution could be the application of lossless compression. Among available methods, JPEG-LS has excellent coding performance. However, it only compresses a single picture with intracoding and does not utilize the interframe correlation among pictures. Therefore, this paper proposes a method that combines the JPEG-LS and an interframe coding with motion vectors to enhance the compression performance of using JPEG-LS alone. Since the interframe correlation between two adjacent images in a medical image sequence is usually not as high as that in a general video image sequence, the interframe coding is activated only when the interframe correlation is high enough. With six capsule endoscope image sequences under test, the proposed method achieves average compression gains of 13.3% and 26.3% over the methods of using JPEG-LS and JPEG2000 alone, respectively. Similarly, for an MRI image sequence, coding gains of 77.5% and 86.5% are correspondingly obtained.
医院和医疗中心每天都会产生大量的数字医学图像，尤其是图像序列形式的，这需要相当大的存储空间。一种解决方案可能是应用无损压缩。在现有方法中，JPEG-LS具有出色的编码性能。然而，它仅通过帧内编码压缩单张图片，并未利用图片之间的帧间相关性。因此，本文提出一种将JPEG-LS与带运动矢量的帧间编码相结合的方法，以提高单独使用JPEG-LS时的压缩性能。由于医学图像序列中相邻两幅图像之间的帧间相关性通常不像一般视频图像序列中那么高，所以仅在帧间相关性足够高时才激活帧间编码。在六个胶囊内窥镜图像序列的测试中，所提方法分别比单独使用JPEG-LS和JPEG2000的方法平均压缩增益提高了13.3%和26.3%。同样，对于一个MRI图像序列，相应地获得了77.5%和86.5%的编码增益。
