Image enhancement technology of long pulse infrared nondestructive testing

In this study, a convenient and economical inspection system using common halogen lamps has been constructed. The corresponding image-processing scheme is developed to identify defects with sharp and clear edges under good contrast. This system has been applied to the localization of defects in composites and rubber coating layered solid propellants. Images with high signal to noise ratio have been acquired and debonding defects with an effective diameter as small as 3~5 mm are able to be detected at a shot.