Most underwater intelligent vehicles and marine remote-control vehicles are equipped with optical cameras for underwater imaging. However, due to the properties of water and its impurity, the quality of the images taken by these imaging devices is not good enough, because the water weakens the light, and the deeper the water, the more the intensity of the light will decreases. Since different wavelengths show different behavior in the collision with the water column, processing and study of these wavelengths is very important to obtain the desired image. The spectral signature can be used for underwater applications. In this research, to increase the quality of underwater images, a new method has been introduced to improve image contrast. In this method, first, with structured lighting, different wavelengths are irradiated to the underwater target in a laboratory environment, then underwater images are processed by the proposed algorithm, and finally, a multispectral image is achieved by stacking images with different wavelengths. The results showed the relative superiority of the proposed method over other methods. Manuscript profile