RAIN, mist and smoke degrade the quality of images produced by surveillance cameras, reducing their usefulness to operators. To tackle this problem, Manchester University spin-off company Dmist Technologies is commercialising a device it has developed to automatically enhance video.

ClearVue is a compact electronic unit which sits between the camera and the monitor. Accepting all major video formats, ClearVue uses a detailed physical model of the scattering processes caused by water droplets and smoke to estimate the contribution of the dispersive media to the observed image. Red, green and blue channel estimates are then used to reconstruct the sharpness and natural colour in real time.

The unit automatically senses and adapts to changing weather and lighting conditions, requiring no user intervention once it is set up.

Images stored on video tapes can also be processed, and associated technology is capable of correcting the extreme contrasts and inaccurate colour rendition in videos made under artificial lighting.