Marr-Hildreth Enhancement of NDE Images
Previous publications [1–5] have demonstrated the usefulness of digital image enhancement techniques for improving visual detection and resolution of features in NDE images. Many of the techniques are high-pass spatial domain convolution filters  which are used to enhance the appearance of edges by removing blur. Two of the major advantages of the more popular edge enhancement operators are their ease of implementation and their rapidity of execution . This makes them very useful for rapid “screening” of images. Their major disadvantages are that they emphasize “noise” as well as edges, and some are directionally dependent operators which tend to suppress features that are not aligned in the “preferred” direction.
KeywordsSpatial Domain Point Spread Function High Spatial Frequency Fourier Amplitude Spectrum Ultrasonic Data
Unable to display preview. Download preview PDF.
- 1.B. G. Frock and R. W. Martin, “Applications of Digital Image Enhancement Techniques for Improved Ultrasonic Imaging of Defects in Composite Materials,” Review of Progress in Quantitative NDE, Vol. 6A, edited by D. O. Thompson and D. E. Chimenti, (Plenum Press, New York, New York, 1987), pp. 781–789.Google Scholar
- 2.M. J. Closier, “Automatic Product Analysis Using X-Rays,” NDT International, 59–65 (1981).Google Scholar
- 4.J. Boutin and C. Forget, “Powerful Image Analysis Techniques for Quantitative Measurements of Materials,” Metal Progress, April 1988, pp. 24–55.Google Scholar
- 5.R. S. Gilmore, R. E. Joynson, C. R. Trzaskos and J. D. Young, “Accoustic Microscopy: Materials Art and Materials Science,” Review of progress in Quantitative NDE, Vol. 6A, edited by D. O. Thompson and D. E. Chimenti, (Plenum Press, New York, New York, 1987), pp. 553–562.Google Scholar
- 7.A. N. Venetsanopoulos and V. Cappellini, “Real-Time Image Processing,” Multidimensional Systems, Techniques and Applications, edited by S. G. Tzafestas (Marcel Dekker, Inc., New York, New York, 1986), pp. 3345–399.Google Scholar
- 8.R. C. Gonzalez and P. Wintz, Digital Image Processing (Addison-Wesley Publishing Company, Reading, Massachusetts, 1977), pp. 210–211.Google Scholar