Efficient Image Browsing with JPEG2000 Internet Protocol

The JPEG2000 image compression standard provides many features to support interactive access to large images. These include efficient lossless and lossy compression, resolution scalability, quality scalability, region of interest coding and spatial random access. The ISO/IEC JPEG committee is in the process of finalizing the JPEG2000 Internet Protocol (JPIP) standard for interacting with JPEG2000 files. JPIP is tightly coupled to JPEG2000 and provides a powerful and flexible client-server architecture. By combining JPIP and JPEG2000 it is possible to store only one compressed file at the server and transmit the resolution, quality, and Window Of Interest (WOI) specified by the client, without having to transmit or decode the entire code-stream. This minimizes server computation, storage and bandwidth. It also reduces the latency for the client. By sending only the data that the client needs the effective compression ratio for client-server applications can be much higher than the file size compression ratio. A prototype JPIP client/server implementation is used to demonstrate resolution scalability, quality scalability and spatial random access of medical images. Efficiency, latency improvements and PSNR quality of the received images are measured as a function of the number of bytes transferred from the server to the client. The choice of JPEG2000 compression parameters, such as precincts and tiles, and the trade-offs of stateful and stateless sessions are discussed. The inclusion of radiology reports as metadata in image files is also demonstrated.