Dwt based image fusion with edge enhancement using Sobel operator

If multiple images of the same scene are available, this can be achieved by image fusion. Image fusion is the process by which two or more images are combined into a single image retaining the important features from each of the original images. Contrast and edges are two important quality factors in image processing. Contrast and edge enhancement are frequently referred two of the most important issues in image processing. Edge is a collection of the pixels whose gray value has a step or roof change, and it also refers to the part where the brightness of the image local area changes significantly. Image edge is the most basic features of the image. When we observe the objects, the clearest part we see firstly is edge and line. In this paper a new fusion technique has been proposed based on the discrete wavelet transform. For edge enhancement we use sobel operator. The input image is decomposed into four frequency sub band images using DWT, and then sobel operator is applied on low-high, high-low, and high-high frequency sub band images for edge enhancement.