A real time, low latency, hardware implementation of the 2-D discrete wavelet transformation for streaming image applications

In this paper, we present a 2-D Discrete Wavelet Transformation (DWT) hardware for applications where row-based raw image data is streamed in at high bandwidths and local buffering of the entire image is not feasible. The latency that is introduced as the images stream through the DWT filter and the amount of locally stored image data is a function of the image and tile size. For an n(1) x n(2) size image processed using (n(1)/k(1)) x (n(2)/k(2)) sized tiles the latency is equal to the time elapsed to accumulate a (1/k(1)) portion of one image. In addition, a (2/k(1)) portion of each image is buffered locally. The proposed hardware has been implemented on an FPGA and is part of a JPEG2000 compression system designed as a payload for a Low Earth Orbit (LEO) micro-satellite, which will be launched in August 2003.