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1. VLSI-Assisted Nonrigid Registration Using Modified
Demons Algorithm
ABSTRACT:
Increasing demand of high-speed portable modules for multimedia applications has
motivated the development of hardware-based solutions for image processing
applications.Most of the nonrigid image registration algorithms are found to be
unsuitable for hardware implementation because of their nonlinearity and
computationally intensive nature. In this paper, an algorithm for nonrigid image
registration based on Demons approximation is proposed. The algorithm has been
simulated in MATLAB and results show a 15% improvement in peaksignal- to-
noise-ratio with a 17% reduction in registration time for 256 × 256 image over the
original Demons algorithm. The proposed algorithm is synthesized in Virtex6-
xc6vlx760-2-ff1760 and maximum synthesized frequency is found to be 174 MHz.
The proposed architecture provides the low cost, high-speed solution for the
registration process, which is also helpful for making a portable system.

2. EXISTING SYSTEM:
Image registration involves minimum two images; one image is known as
reference image and the other one is the target (or moving) image. Reference and
target images are related through some transforms. These transforms are known as
nonrigid transform (also known as elastic or deformable transform), if they are
capable of modeling nonlinearity and local geometric distortion caused by the
imaging system [1], [2], [5]. Nonrigid transformations include radial basis
functions, physical models, and large deformation models. The choice of
deformation model is of great importance because it involves compromises
between computational efficiency and richness of description. Nonrigid
transformations are highly nonlinear and computationally expensive [2], [5].
Memory intensive characteristics of nonrigid algorithms further limit the
realization of hardwarebased portable systems. A general framework for image
registration is shown in Fig. 1.

3. PROPOSED SYSTEM:
In this paper, diffusion model has been chosen for nonrigid image registration due
to its computational efficiency and capability of solving the complex partial
differential equations. Most of the work on diffusion model is inspired by the work
of Thirion [6] and classified as Demons approaches. Demonsbased approaches for
nonrigid registration utilize the concept of optical flow and thermal diffusion,
which directly explores the image raw intensities and can accelerate the
registration process [3], [7]. Researchers developed new variants of the Demons
algorithm and successfully applied to fluid and curvature [8]. New variants such as
log- and ilog-Demons use logarithmic and exponential methods of optical flow
calculation. Logarithmic and exponential functions are nonlinear and
computationally intensive, which result in the reduction of computational
efficiency and increased hardware complexity. The authors of this paper have
extended the method of Wang et al. [9] and proposed efficient Demons-based
approach as well as its hardware architecture, which utilizes parallel processing
and pipelined streaming models to accelerate the computation process.

4. SOFTWARE IMPLEMENTATION:
 Modelsim 6.0
 Xilinx 14.2
HARDWARE IMPLEMENTATION:
 SPARTAN-III, SPARTAN-VI