PROBLEMS OF GEOMETRICAL INTERPRETATION – RECOGNITION
OF PIECE-WISE SMOOTH CONTOUR FORMS
SHULGA
V.I.
http: // shulga.tripod.com/formaved
ABSRTUCT
- Interference-defended - joint solving of segmentation and approximation
problems, based on usage of bell-like (fuzzy) membership function.
– Bell-approximation.
Approximating
segments with maximal functional accentuation - loading in center,
with graduate step-by-step falling down of it to the ends. – Segments with
fuzzy ends - contiguous segments. – As much as possible
strict – as much as possible lengthy - universal linear units. –
Geometrical ground of primary approach – delineating
("spanning-capture") of arbitrary - curvilinear contour forms.
Unison of positional hypotheses as interference-defended indicator of
simultaneous detection and recognition of defined configurations. Possibility
of operation under partial overlapping of sought objects.
- Keywords:
- data modeling, regression analysis, interpolation, approximation,
segmentation, piecewise-smooth curves, splines, fuzzy sets; shape analysis,
image analysis, pattern recognition, image recognition, template matching,
Hough transform; computer vision, machine vision, industrial vision, robot
vision, drawing recognition, documents analysis; analysis of schemes, maps,
graphs, trajectories and signal processing as a whole; applied geometry.
INTRODUCTION. Conceptual content.
- The present work deals with the problem of jam-resistant representation
of contour forms as sets of elementary line segments. It elaborates
the problem of following positional detection (detection with finding the
position and orientation) among these sets of specified configurations.
These configurations are determined through their samples (templates) which,
herein, themselves represent the individual images of piecewise-smooth
objects. Origin materials were contour preparation of actual images.
Line - one of primary geometrical
concepts by means of which the man describe of environmental actuality.
An apparent ease - "evidence" from which the man operates with
his own abstract representations in this field, makes false impression
about simplicity of algorithmization (transposition on a computer)
such operation. One of key tasks here - a partition of registered linear
shapes on individual components - the elementary segments. Difficulties
start already in the elementary case - a case "angular" - polylines.
It appears, rather uneasy to pick out an angle in a actuality when
lines are set discretely as a set of the individual points scattered
around of true positions.
In the first section
of the present work it is arising here difficulties systematically
understand. The physical sense of minimization of mean-square
deviation - base procedure of the analysis of actual data is considered.
Necessity of usage of bell-like (fuzzy) function of a membership of contour
points to individual segment is obviously shown. Tasks of partition of contour
configuration on individual segments and their approximation are reduced
together - to searching local maxima of a "fuzzy" measure of likeness constructed
on the basis of such function.
In the second section
it is considered the essence more complicated problem, namely, - if we should divide into units a lines having the smooth shapes,
- when generally there are no precise angles, - one segment gradualy
- smoothly pass into another. The concept of segment
with fuzzy ends is developed. It is suggested to use a membership
function of bell-like shape also in the longitudinal (axial)
direction.
Such - bell-like function
enables to rest on the length of the contour lines for a maximum
degree when they are approximated with the curves of some standard type,
mainly in the center, with gradual weakening in the periphery direction,
according to their gradual divergence.
The obtained approximating
segments are named as contiguous segment because their non-sharp
(fuzzy) ends are only adjacent, in the general case, to contours
under approximation.
In general,
contiguous segments - the segments with fuzzy ends - are themselves
a development of the concept of tangent comparison/juxtaposition
of curves. They lead up such the comparison to a maximum of a
geometrical definitiveness. The rigid conformity in the center and
gently at the ends, i.e. contiguity, is in the whole the maximum
of geometrical strictness, which can have the universal units
of primary segmentation/approximating of arbitrary shaped curve
lines.
In the second section common
principles and technique particularities of implementation of the concept
of contiguous segments are considered. The general view of function of
a likeness which local maxima define these segments is represented. Outcomes
of experimental examination are discussed.
In the third section
the problem of practical usage of contiguous segments in the task of
positional detection of arbitrary formed contour objects under their exemplars
is considered. The offered solution is based on a procedure of registration
of a unison of parametric (positional) hypotheses about probable
positins of sought configuration which are independently generated by separate
primary fiatures - fragments. As such indications - fragments contiguous
segments here appear. Common ontological (essential) cscheme of such procedure
is offered. Practical implementation of this approach leads to procedure
of detection similar to procedures in which basis known Hough transform.
The offered summarizing enables to see their depth generality - to simplify
logic of their development and the further development.
Moreover, and what is above all, the developed procedure is based on
an application of the universal primery elements, which limit the sets
of the hypotheses about the global (positional) parameters of the search
objects in the maximum. It is applied the described above tangent-contiguous
segments with fuzzy ends. It was an use of these initial units that enabled
us to draw the carried out search the hypothesis unison principle
up to a possibility of the constructive application in the problem of positional
detection of arbitrary form objects. In the other hand, it was the use of
such way of detection that enable a principal way to "cut up" the "sliding
uncertainty" of contiguous segments that have its place in general. It may
be told about uncial unity of this conceptual pair.
At this base, the sequence of procedures was created for efficient
solving the problem of segmentation-approximation and following positional
detection (detection with definition of the position and orientation) of
arbitrary form flat contour figures with respect to their samples in the
case when one figure may partially overlap another.
All these may be essentially advanced and widely applied as the whole
and individually.
- The paper is a otherwise accented
variant of the following work with some specifications in the terminology:
- Shulga V.I. "Complex (Collection) of Interference
Defended Procedures of Contour Boundary Approximation and Recognition
of Objects on Contour Images (research work)" / Glushkov Institute of Cybernetics,
Academy of Sciences of the Ukraine, Kiev, 1992, 75p. (In Russian) / Deposited
in the All-Union Institute of Scientific and Engineering Information (Moscow),
04.01.92, N 12-B92.
https://shulga.tripod.com/GEOLIN/glnfl1.htm
In its turn, this work summarizes the author's investigations, the
first publications are dated 1981 [2] and
1982 [19] years. In the scientific
literature, there is lot of papers, thematics of which intersects with
the subjects of the present investigation. In Internet there is a wide
set of sites, which is searched under enquiries: «weighed least
squares», «fuzzy lines», «generalized Hough transform»
… Definition of relationship degree of these materials with
the present work and determination here authoring superiority – is a subject
for different examination. To not passing virtues of the present
work, it is possible to refer that instead of scrappy hints and sacral
appeals to higher mathematics, semantic - physical explanations
are given, which are a basis of any science. Besides all procedures is united
in the unique technological line-up, showing a place of each concepts in
the common problem of positional detection - recognition as a whole.
TABLE OF CONTENTS:
INTRODUCTION. Conceptual content.
1. BELL-APPROXIMATION.
1.1. Physics of approximation.
1.2. Ordinary way of functional correction.
1.3. Essential motivation of advanced correction.
1.4. General statement of the problem.
1.5. Bell-approximation in the contour boundary description.
1.6. Choice of the width of the bell-like membership function.
1.7. Automatic correction of the width of membership function.
2. SEGMENTS WITH FUZZY ENDS.
2.1. Statement of the problem.
2.2. Procedural particularities. Results of the experiments.
2.3. The possible improvements.
2.4. Longitudinal fixation of the contiguous segments.
2.5. Sliding of linear elements.
3. POSITIONAL DETECTION VIA REGISTRATION OF UNISON OF PARAMETRICAL
HYPOTHESES.
3.1. Essential statement of the problem.
3.2. General statement of the problem.
3.3. Hypotheses unison in the positional detection.
3.4. Main particularities of application of unison-technique of positional
detection.
3.5. Procedural particularities. Results of experiments.
3.6. The possible improvements.
SUMMARY.
REFERENCES.
APPENDIX.