6533b831fe1ef96bd1299813

RESEARCH PRODUCT

<title>Restoration of a short-exposure image sequence degraded by atmospheric turbulence</title>

subject

description

This paper deals with the restoration of the shape of an object observed with a high-resolution infrared imaging device, through atmospheric turbulence. The propagation path is quite long (a few tenth kilometer) and the image is thus disturbed. A sequence of short-exposure images of the interesting object is recorded. We can see that the object shape fluctuates randomly during the sequence, but that its edges remain sharp, thanks to the very short exposure time. A bayesian analysis of the Fourier descriptors associated to the edges shows that the optimal shape is the one corresponding to the mean Fourier descriptors. We thus propose two ways to estimate this shape. The first one consists in matching point-to-point each pair of successive edges in the sequence and take the average position of each point. The second one consists in applying an active contour (a snake) on the images. This contour evolves with the object shape during the sequence. From the set of positions of its nodes, we can calculate quite easily the optimal shape.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.