Author
Abstract
The wide spread of devices that use image processing in its
functions, like cellular phone and digital cameras, increases the need for
specialized processors for these functions as a replacement for software
programs that consume more time and resources. This paper presents a
hardware description for discrete wavelet transform (DWT) module in
VHDL language. The design involves the forward DWT (fDWT) and its
inverse (iDWT) characterized by variable number of transformation levels,
ranging from one level to seven levels. Each one of these two modules is
designed as hierarchical scheme that uses one-dimensional processing
module twice to represent two-dimensional processing. The module can be
used repeatedly on the same image for multilevel processing. Three
versions of the design are presented (v64, v128 and v256), each one
adapted different image size. Synthesis process showed that the design
frequency is about 56MHz. The simulation process showed that the
maximum possible rounding error is about 0.012%. This resolution with the
variable number of processing level adapts this design to fit in many
applications. Finally, a comparison of the proposed design with other
related work is presented, considering performance and specifications.
Keywords
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