Underwater imaging and real-time optical image processing under illumination by light sources with different wavelengths

To improve the underwater imaging quality under the complex underwater imaging environment, different water environments are simulated by adding the blue-green ink and milk for the absorption and scattering effects respectively, and light sources with different wavelengths are employed for illumination. To eliminate or alleviate the effect of absorption and scattering, an optical image processing technique is proposed after analyzing the collected characteristics of images with different light sources. The experiments show that the blue-green light has better transmission to overcome the water absorption and the red light with longer wavelength exhibits clearer illumination to alleviate the scattering influence and obtain target image information. The scattering noise can be removed with the collected differential image grey-scale value of the red light and blue-green light. The image processing technique in both Windows and Android systems is demonstrated, achieving a high performance. Compared with the unsharp mask (USM) sharpening algorithms, it has the advantages of simpler computation and good real-time performance.