  In this research paper, authors propose multimodal brain image registration
using discrete wavelet transform(DWT) followed by Gaussian pyramids. The
reference and target images are decomposed into their LL, LH, HL and LL DWT
coefficients and then are processed for image registration using Gaussian
pyramids. The image registration is also done using Gaussian pyramids only and
wavelets transforms only for comparison. The quality of registration is
measured by comparing the maximum MI values used by the three methods and also
by comparing their correlation coefficients. Our proposed technique proves to
show better results when compared with the other two methods.
