Within the expanding paradigm of medical imaging in Teleradiology-Telemedicine there is increasing demand for transmitting diagnostic medical imagery. These are usually rich in radiological contents and the associated...Within the expanding paradigm of medical imaging in Teleradiology-Telemedicine there is increasing demand for transmitting diagnostic medical imagery. These are usually rich in radiological contents and the associated file sizes are large which must be compressed with minimal file size to minimize transmission time and robustly coded to withstand required network medium. It has been reinforced through extensive research that the diagnostically important regions of medical images, the Region of Interest (ROI), must be compressed by lossless or near lossless algorithm while on the other hand, the background region be compressed with some loss of information but still recognizable using JPEG 2000 standard. We develop a compression model and present its application on MRI images. Applying on MRI images achieved higher compression ratio 16:1, analogously minimum transmission time, using MAXSHIFT method proved diagnostically significant and effective both objectively and subjectively.展开更多
目的探讨JPEG2000标准中基于兴趣区(region of interest,ROI)的编码方法,重点讨论了标准中的最大上移(maximum shift,maxshift)方法。方法Maxshift方法缩放ROI的系数,使得属于ROI的所有信息在码流中放在背景区(back-ground,BG)的信息之...目的探讨JPEG2000标准中基于兴趣区(region of interest,ROI)的编码方法,重点讨论了标准中的最大上移(maximum shift,maxshift)方法。方法Maxshift方法缩放ROI的系数,使得属于ROI的所有信息在码流中放在背景区(back-ground,BG)的信息之前。改变图像的量化方式和码流截断点的位置,就能获得不同质量的ROI和BG。结果在低比特率(大约小于0.05bpp)时,ROI和BG具有近似的图像质量。随着比特率的增加,ROI的质量迅速提高。结论Maxshift方法处理任意形状的ROI时,不需要编码形状,解码器既不用解码形状,也不需要生成ROI掩膜,因此更加简单。展开更多
文摘Within the expanding paradigm of medical imaging in Teleradiology-Telemedicine there is increasing demand for transmitting diagnostic medical imagery. These are usually rich in radiological contents and the associated file sizes are large which must be compressed with minimal file size to minimize transmission time and robustly coded to withstand required network medium. It has been reinforced through extensive research that the diagnostically important regions of medical images, the Region of Interest (ROI), must be compressed by lossless or near lossless algorithm while on the other hand, the background region be compressed with some loss of information but still recognizable using JPEG 2000 standard. We develop a compression model and present its application on MRI images. Applying on MRI images achieved higher compression ratio 16:1, analogously minimum transmission time, using MAXSHIFT method proved diagnostically significant and effective both objectively and subjectively.
文摘目的探讨JPEG2000标准中基于兴趣区(region of interest,ROI)的编码方法,重点讨论了标准中的最大上移(maximum shift,maxshift)方法。方法Maxshift方法缩放ROI的系数,使得属于ROI的所有信息在码流中放在背景区(back-ground,BG)的信息之前。改变图像的量化方式和码流截断点的位置,就能获得不同质量的ROI和BG。结果在低比特率(大约小于0.05bpp)时,ROI和BG具有近似的图像质量。随着比特率的增加,ROI的质量迅速提高。结论Maxshift方法处理任意形状的ROI时,不需要编码形状,解码器既不用解码形状,也不需要生成ROI掩膜,因此更加简单。
