The widespread use of multi-detector CT scanners has been associated with a remarkable increase in the number of CT slices as well as a substantial decrease in the average thickness of individual slices. This increased number of thinner slices has created a marked increase in archival and network bandwidth requirements associated with storage and transmission of these studies. We demonstrate that although compression can be used to decrease the size of these image files, thinner CT slices are less compressible than thicker slices when measured by either a visual discrimination model (VDM) or the more traditional peak signal to noise ratio. The former technique (VDM) suggests that the discrepancy in compressibility between thin and thick slices becomes greater at greater compression levels while the latter technique (PSNR), suggests that this is not the case. Previous studies that we and others have performed suggest that the VDM model probably corresponds more closely with human observers than does the PSNR model. Additionally we demonstrated that the poor relative compressibility of thin sections can be substantially negated by the use of JPEG 2000 3D compression which yields superior image quality at a given level of compression in comparison with 2D compression. Additionally, thin and thick sections are approximately equally compressible for 3D compression with little change with increasing levels of compression.
In this paper, a robust image transmission scheme based on JPEG2000 is proposed for packet erasure channels. Error resilience functionalities provided by JPEG2000 are utilized to control the source coding efficiency and the robustness according to channel conditions. Furthermore, together with the proposed interleaving scheme, some erasures can be recovered. Experimental results show the effectiveness of the scheme.
An unequal loss protection framework for transmission of JPEG2000 codestreams over packet erasure channels is presented. A joint source-channel coding approach is adopted to form the JPEG2000 codestream and assign the appropriate amount of protection to different sections of the codestream. Experimental results indicate that the proposed scheme yields excellent performance across a wide range of packet loss rates.
We introduce techniques that improve the error resilience of JPEG2000 against packet losses. The presented methods operate on JPEG2000 codestreams and consider the properties of different codestream segments. Experiments indicate that error resilience of JPEG2000 codestreams against packet losses can be improved significantly using these techniques. The performance of the proposed methods compares favorably with existing algorithms.