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I was fortunate to have had numerous conversations with Professor J.C. Simon
over the years and I will recount three of our recurring topics, all of them
central to his work in OCR.
1. The importance of irregularities for feature selection. The volume "From
Pixels to Features" edited by him (Amsterdam: North Holland, 1989) contains
two papers:
- J-C. Simon Ä Complementary Approach to Feature selection," pp. 229-236.
- T. Pavlidis and D. Lee "Residual Analysis for Feature Extraction," pp. 219-227.
The key idea in both papers is that what is predictable is not interesting.
A smooth straight curve does not contain any information. Thus the shape I
may be considered as a zero. L is distinguished because of its corner, the
anomaly in its shape. Similarly the intersection of the two lines in X is
the informative feature. One may argue that this approach is presumed by the
old analysis of the difference between representation and discrimination,
but there is more to the story. The traditional statistical analysis assumes
that features have been already extracted; in order to apply the concept to
feature extraction one must define what is the predictable basis.
2. The importance of the engineering approach to solving problems as
opposed to relying on a single methodology. The fields of image analysis and
pattern recognition have been plagued by fashions: statistical pattern
recognition, syntactic pattern recognition, graph grammars, connectionism,
relaxation techniques, neural networks, fuzzy logic, hidden Markov models,
etc. All of these techniques are quite valid and useful tools under certain
conditions. Problems arise only when they are presented as panaceas that
each can be used to solve all problems in the field. The engineering
approach requires understanding the structure of the objects to be
recognized and apply the appropriate combination of techniques. The
following papers are example of such approaches that integrate different
methodologies:
- S. Kahan, T. Pavlidis, and H. S. Baird, ``On the Recognition of Printed
Characters of Any Font And Size'', IEEE Trans. on Pattern Analysis and
Machine Intelligence, PAMI-9 (1987), pp. 274-288.
- J-C. Simon, Öff-Line Cursive Word Recognition" Proc. IEEE, vol. 80
(1992), pp. 1150-1161.
3. The importance of senior researchers being closely involved in the
research to the point of writing code themselves. Both Professor Simon and
myself had spent considerable in writing code to the bewilderment of our
colleagues who thought that senior researchers should not write code
themselves. Once he asked what should he tell such critics. I told him my
ßtock" reply to such criticism. Professors of surgery perform surgery with
their own hands, no matter how senior they are; therefore it is only
appropriate that professors of computer science should write their own
programs. Would a person be willing to be treated by a physician who has
been taught by professors who had never treated patients? Maybe the hiring
of college graduates who have been taught by faculty who never did any
programming themselves causes the sorry state of modern software. I will
elaborate on this point in view of the advances in software tool
development.
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