Image Processing Reference
In-Depth Information
Fig. 11.9. The illustration of a segmentation-free OCR for Sinhala text (Sri Lanka), imple-
mented by use GST, after [186]. The points are painted colored at the places where a support
for a GST character template has been found
in analogy with Figs. 11.4 and 11.5. Similarly, Fig. 11.10 illustrates the recognition
of Ethiopian script.
Example 11.10. Two-dimensional gel electrophoresis is an important tool of pro-
teomics, e.g., in search of new drugs. The result is 2D data that can be viewed as
images(Fig.11.11).Thesecontainspotsthataremapsofalargenumberofproteins,
requiring automatic image processing for efficient analysis. Quantification of indi-
vidual proteins and tracing changes in expression between gels require accurate pro-
tein detection. One can approach the problem by modeling circles via the monomial
familycorrespondingto n =
2.Asetofcomputationallycheapandrobustsymme-
try derivative features can implement a detector that is particularly tuned to circles.
Inthesamefigure,thecolorimagerepresents I 20 usingtheCTimpliedbylog z .The
red hue represents the presence of circles. Brightness represents the certainty. Using
this model as one of the features, an efficient classification and segmentation can be
achieved [182].
11.12 Further Reading
In computer vision, normally one does not locate an edge or compute the direction
of a line by correlation with multiple templates consisting of rotated edges, incre-
mented with a small angle. However, multiple correlations with the target pattern
rotated in increments are commonly used to detect other shapes. This approach is
also used to estimate the direction of such shapes. The number of rotations of the
template can be fixed a priori or, as in [30], dynamically. The precision of the es-
timated direction is determined by the number of rotated templates used or by the
amount of computations allowed. Although such techniques yield a generally good
precision when estimating the affine parameters, which include target translation and
rotation, in certain applications a beforehand undetermined number of iterations may
not be possible or be desirable due to imposed restrictions that include hardware and
software resources. Furthermore, the precision and/or convergence properties remain
satisfactory as long as the reference pattern and the test pattern do not violate the
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