Chapter 2 Reference Manual
Ranger E/D
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Overview
Scatter Component
The Scatter component is used for measuring how the light is distributed just below the
surface of the object. This can be used for emphasizing properties that can be hard to
detect in ordinary grayscale images, and is useful for example for detecting knots in wood,
finding delamination defects, or detecting what is just below a semi-transparent surface.
Figure 2.9 – Grayscale (left) and scatter (right) images of wood. The two knots are easy to
detect in the scatter image.
The scatter component measures the intensity along two rows on the sensor, and the
result is two intensity profiles – one that should be the center of the laser line (direct), and
one row a number of rows away from the first row (scatter).
The scatter profile can be used as it is as a measurement on the distribution of the light,
but the result will usually be better if the scatter profile is normalized with the direct inten-
sity profile.
Figure 2.10 –Using scatter to detect delamination defects. Where there are no defects,
very little light is reflected below the surface, resulting in a sharp reflex and
low scatter response. Where there is a defect, the light is scattered in the
gap between the layers, resulting in a wider reflection and thus high scatter
response.
Bubble
Ranger
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