Discrete wavelet transformations (DWT) followed by embedded zerotree encoding is a very efficient technique for image compression \cite{TenLectures, Shapiro, Spiht}. However, the algorithms proposed in literature assume random access to the whole image. This makes the algorithms unsuitable for hardware solutions because of extensive access to external memory. Here, we present an efficient architecture for computing DWT of images, which is based on a partitioned approach for lossy image compression~\cite{Ritter}. The architecture achieves its computational power by using pipelining and taking advantage of the flexible memory configurations available in FPGA's.