Detection of a random edge and its application to interior surface measurement
UNSPECIFIED (1996) Detection of a random edge and its application to interior surface measurement. In: Conference on Applications of Digital Image Processing XIX, DENVER, CO, AUG 07-09, 1996. Published in: APPLICATIONS OF DIGITAL IMAGE PROCESSING XIX, 2847 pp. 214-222.Full text not available from this repository.
A random edge is the centre of an in-focus-strip which is formed by viewing a vertical surface through a conventional microscope. The in-focus-strip is the image of the surface which locates inside the depth of the field of the microscope. The image of the surface which locates outside of the depth of the field is blurred and contains only low frequency illumination profile. The location of this random edge has been used to make internal measurements within holes as small as 200 microns in diameter. A specialised edge detector has been designed to 'find' the centre within the in-Focused region. The detector first locales the in-focus-strip. It then extracts the surface background detail from the out-of-focus part of the image. This out-of-focus information is used to effectively normalise the intensity distribution over the image. The image is then smoothed to remove random noise. The location of the centre of the in-focus-strip is then found from the application of a weighting function constructed from the position of individual details located within the edge region.
This method has been used in measuring inside a 0.25mm diameter hole. The hole is used to carry the coolant through a turbine blade. The accuracy of the measurement is better than +/-3 mu m.
|Item Type:||Conference Item (UNSPECIFIED)|
|Subjects:||Q Science > QC Physics|
|Series Name:||PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE)|
|Journal or Publication Title:||APPLICATIONS OF DIGITAL IMAGE PROCESSING XIX|
|Publisher:||SPIE - INT SOC OPTICAL ENGINEERING|
|Number of Pages:||9|
|Page Range:||pp. 214-222|
|Title of Event:||Conference on Applications of Digital Image Processing XIX|
|Location of Event:||DENVER, CO|
|Date(s) of Event:||AUG 07-09, 1996|
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