Image archival and retrieval makes significant demands on compression technology. An image library will be large and heterogeneous--thus the need for deep lossy compression and robust performance across diverse content. For long term archival, the codec must provide a (near) lossless mode. Ideally, one file format will support both. It should allow progressive transmission and be multi-resolution, supporting full-size, screen-size, and thumbnail-size versions. This paper presents a new spline-based image compression scheme that satisfies these objectives.