Development of Multi-focus Image Fusion Technique using Discrete Wavelet Transform (DWT) for Digital Images

Image fusion is the process which combines information of multiple images from the same scene. The resultant fused image is a new image that have the most desirable information and characteristics of each input image. One of the main application of image fusion is merging the gray-level high-resolution panchromatic image and the colored low-resolution multispectral image. It has been found that the standard fusion methods perform well spatially but usually introduce spectral distortion. To overcome this problem, numerous multi-scale transform based fusion schemes have been proposed. In this paper, we focus on the fusion methods based on the Discrete Wavelet Transform (DWT), the most popular tool for image processing. Due to the numerous multi-scale transform, different fusion rules have been proposed for different purpose and applications.