Abstract: JPEG XR is a new image coding standard that achieves high compression performance and low complexity. In this study, we propose a novel architecture of Lapped Biorthogonal Transform (LBT) for JPEG XR encoding using an optimized Quadriphase-RAM (QRAM) and a fully pipelined LBT module. In the previous architectures, the whole image data are stored in the main memory so that the waste of memory and the delay for the whole image acquisition must be inevitable. The proposed QRAM minimizes the memory size and improves the speed of image processing and the fully pipelined LBT module achieves higher throughput than that of the previous architectures. Results show the proposed architecture which achieves 121.2 M pixel/sec at 125 MHz can be used for the real-time JPEG XR encoding.