Wavelet-based image target detection methods

Detection of small, faint, and/or obscured targets in a sequence of noisy images is not trivial. In this case, target and background (texture) features are generally undistinguishable in the original image domain. So, the image has to be transformed to a domain in which those features can be separable. The wavelet transform has been shown to be an excellent methodology that image segmentation can be performed through exploiting the wavelet multi-scale analysis capability. This paper reviews general wavelet-based methods for image target detection. Although the paper reviews the most recent target detection methods using wavelet, which are available in open literature, it focuses on illustrating the different ideas of using wavelet coefficients as a tool for target-background separation. Furthermore, this paper has the objective to offer a quick look to the many approaches, to put in light the authors' most recent developments in this field, and to serve as a background for new advances.