Efficient fusion of multimodal medical images has been a constant topic of research. A variety of fusion rules have been proposed in the literature, which fuses the information in MRI and CT images of the organs of interest. The prime aim of all these fusion techniques has been to maximally make available the information from both the images in a single composite image. This aids the medical practitioners in their analysis. Most of these existing techniques give more importance to the quality of the fused image, than the computational complexity. Fusing the multimodal images in the transform domain usually involves fusion of all the transform domain coefficients, whose number increases with the increase in the number of multiresolution levels chosen. In this research, we have proposed a fusion technique based on Complex Wavelet Transform and Phase Congruency. This method is computationally efficient, in terms of the number of transform domain coefficients participating in the fusion process and visual quality. The concept of phase congruency makes sure that the edge information in the source images gets preserved in the fused image. It also reduces the number of transform domain coefficients taking part in the fusion process by a huge margin, when compared with the conventional transform domain fusion techniques. An edge preservation quality measure has been used to quantitatively analyze the edge preservation capacity of the proposed technique. The quality of the fused image is analyzed using some existing quality metrics. Experimental results exhibit the efficiency of this proposed technique, in producing a fused image with lesser number of coefficients without compromise on visual quality.
A. T. and Dr. Latha Parameswaran, “A Computationally Efficient Edge Preserving MRI-CT Image Fusion Technique using Complex Wavelet Transform and Phase Congruency Fusion Rule”, European journal of Scientific Research, vol. 112, no. 4, pp. 469-483, 2013.