A Comparison of Hardware Implementations of Biorthogonal 9/7 2D-DWT:Lifting Structure Versus Flipping Structure

In this paper, we compare filter banks for calculating the DWT-the lifting method. We look at the traditional lifting structure and a recently proposed “flipping” structure for implementing lifting. Both filter bank structures are implemented on an Altera field-programmable gate array. Flipping structure can provide a variety of hardware implementations to improve and possibly minimize the critical path as well as the memory requirement of the lifting based discrete wavelet transform by flipping conventional lifting structures. The quantization of the coefficients plays an important role in the performance of all structures, affecting both image compression quality and hardware metrics. We design several quantization methods and compare the best design for both approaches. The results show that for the same image compression performance, the flipping structure gives the smallest and fastest, low-power hardware.