Underwater image transmission and blurred image restoration

Because light is scattered and absorbed by seawater, the images obtained un derwater are always blurry after transmitted through a certain distance. Th e point spread function (PSF) and modulation transfer function (MTF) are im portant properties of seawater to predict underwater light propagation and underwater image quality. We describe the laboratory facilities to measure the PSF and MTF of water body by the image transmission method and the rest oration methods of underwater blurred images. The measured results are give n and compared with the theories. The blurred images of a bar target transm itted through different water paths are restored with the measured MTF usin g a Wiener filter. (C) 2001 Society of Photo-Optical Instrumentation Engine ers.