Synthetic Aperture Focusing Technique for Image Restoration
L.Guimaraes and A.W. Elbern, Dep. de Engenharia Nuclear, UFRGS, Porto Alegre, RS, Brasil
FULL-TEXT - ABSTRACT The Synthetic Aperture Focusing Technique (SAFT) has been used to restore ultrasonic images obtained either from B or C scans with focusing distortion. With the use of this technique an improvement of the image resolution can be obtained, without the use of the traditional ultrasonic lenses. This work shows the practical implementation of SAFT for scan B, by presenting an algorithm and the resulting image. For SAFT to function properly, it is necessary to know accurately the path traveled by the ultrasound from the transducer to target and back again. Therefore a geometrical model of ultrasonic signal and its correlation to adjacent scan A lines are used to restore the image. In order to minimize the execution time of this algorithm, the correlation is calculated only between few lines adjacent to the analyzed line, in a correlation window. The results obtained with our algorithm implemented in C language, is quick and efficient in improving the lateral resolution to the images submitted to it.
Publication Source: NDTISS '99 - International Symposium on NDT Contribution to the Infrastructure Safety Systems, Nov 1999 in Tores Brazil.
Publisher: Center of Tecnology, Federal University of Santa Maria (UFSM) - [Homepage]
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