Heraldic Applications of Computational Linguistics, Computational Geometry and Image Processing

Introduction
The official definition of a coat of arms is not the depiction
of the arms but the blazon, which is the text describing
the arms. It requires a skilled heraldic artist to render the arms
from the blazon. Anyone well versed in heraldry can perform
the inverse operation, to render the blazon from the arms.
The paper describes projects to automate these processes, by
capturing the herald painter's skills and drawing upon
computational linguistics (constructing the syntax and parsing
the blazon) and computational geometry (positioning and sizing
the components) and by using image processing techniques
(identifying the components, layer by layer, that make up the
shield). More importantly, the paper emphasizes that these
techniques have wider application in the arts and humanities.
Context
An important rationale for many computer applications is
to capture skills so that tasks can be tackled by unskilled
operators. In the visual arts, computers have long been used to
help people draw or paint two dimensional pictures or to model
and render three dimensional scenes.
One area that provides a considerable challenge is heraldry. It
requires artistic skills to render the arms from the blazon,
thereby limiting the rôle of those unskilled in the use of pen
and paint. It also requires heraldic knowledge to depict or
recognize arms.
The blazon defining the Queen's University's arms (Figure 1)
is: Per saltire azure and argent, on a saltire gules, between in
chief an open book and in base a harp both proper, in dexter
a hand couped of the third, and in sinister a sea-horse vert
gorged with a mural crown of the fourth, an Imperial crown
of the last. From this definition any competent heraldic artist
can draw the shield whereas the quality of computer programs
that attempt to automate this process is at present limited and
inferior. Much the same was said of the printer's art when
desktop publishing was first attempted.
Figure 1: The Queen's University of Belfast
Several exploratory projects to automate this task have been
undertaken at Queen's by final year undergraduates and by
taught course postgraduates.1 The results have been promising
but, because of the time available to those students, limited.
Now is the time to build upon those studies to produce a much
more acceptable application that not only consolidates the work
done to date but also addresses the more challenging questions
that have yet to be tackled. This paper discusses the progress
so far and outlines what problems remain and how they might
be solved.
The artist's skill shows in the disposition and scale of the
components. No program can rival the inventiveness of an artist
but there remains the question of whether an acceptable
rendition can be generated. Such an application draws upon
computational linguistics and computational geometry; it also
entails constructing a dictionary of heraldic terms and a
corresponding library of heraldic images. It may be that a
semi-automatic solution is necessary, allowing the user to make
fine adjustments. In fact, some human intervention will be
required because the set of components that may appear in a
coat of arms is unbounded and new ones will inevitably be
encountered and will have to be entered into the dictionary and
library.
The inverse operation, of deconstructing a coat of arms to
produce the blazon, has also been attempted in a student project
(Flanagan) and is now to be tackled more seriously, using
experience gained from another student project (Taylor) that
uses image processing techniques to extract the contours and other information from a map. Again, the problems and how
they might be resolved are discussed in the paper.
Benefits
The language of blazon has been in continual use since the
Middle Ages. Based on the French of the time, and
subsequently adapted, it has a reasonably precisely defined
grammar and a substantial vocabulary that is extended as
necessary. To most people that are neither heralds nor heraldists
it appears to be arcane. This project should help to make
heraldry more widely accessible; it should make heraldic and
artistic skills available to the unskilled and it should also be a
useful tool for heralds, at least for intermediate sketches if not
for the final grant of arms.
It should also make the production of illustrated rolls of arms
feasible as, at present, there are not enough heraldic artists to
produce an illustrated version of, say, Burke's General Armory,
which describes thousands of shields listed by the names of
their owners. The inverse operation of identifying the owners
of shields is generally accomplished using Papworth's Ordinary,
which is not illustrated and can be difficult to use; automation
can play a useful part here. Heraldic offices are now beginning
to use computers in a more imaginative way and they will want
to develop indexed and illustrated databases of arms.
More generally, it may encourage those working in the visual
arts to develop more precise written descriptions of their
artifacts. Heraldry is somewhat stylised and lends itself to
precise formal descriptions; that is not the case for most art but
it may be that the correspondence between blazon and image
might encourage the development of more precise descriptions
of other works of art, as happens with music or dance notation.
Computational techniques for the construction of grammars,
the disambiguation of syntax and the parsing, processing and
indexing of texts have wide application; we have experience
with subsets of Latin, English, French, Spanish and Esperanto
as well as blazon.
Geometrical and topological techniques for describing and
manipulating two and three dimensional shapes are also widely
applicable; we have experience of applying such techniques to
mechanical and aeronautical engineering artifacts. It is now
time to apply these methods to other areas of scholarship.
Examples & Problems
By way of example, the following coats of arms (Figures
2a-2g) are taken from Foster's Feudal Coats of Arms and
have been generated automatically by computer program from
blazons, some of which have been rephrased.
Figure 2a: Or, on a cross gules five escallops argent.
Bigod, Rauff, of Settrington, Yorks
Glover Roll &c.
Ascribed also to John in the St. George Roll, and to Sir
Raffe, of Norfolk, in the Parly. Roll.
Figure 2b: Azure, six eaglets, 3, 2, 1, or.
Biblesworth, Sir John
Ashmole Roll
Also ascribed to Walter.
Figure 2c: Per pale or and vert, a lyon rampant gules.
Bigod, Roger, Earl of Norfolk,
Earl Marshal of England
at the battle of Falkirk 1298 and sealed the Barons' letter to
the Pope 1301, pp xv, xxiv.
Figure 2d: Quarterly or and gules, a bend sable.
Beauchamp, John, Walter, and William, of Bedford (H. III Roll) Parliamentary, Norfolk and St. George Rolls
[bend gules; in other MSS. bend sable occurs].
Figure 2e: Azure, three cinquefoyles or.
Bardolf, Sir Hugh, a baron 1299
Sealed the Barons' letter to the Pope 1301, pp xvii, xxiv;
bore at the battle of Falkirk 1298 and at the siege of
Carlaverock 1300.
Figure 2f: Or, a chevron azure.
Bastard (---), of Kitley, Devon
Shirley.
Figure 2g: Gules, on a chief argent two mullets sable pierced or.
Bacon, Sir Edmond
at the first Dunstable tournament 1308.
Compound coats, like the arms of Queen's College Belfast
(Figure 3) or those of the Royal University of Ireland (Figure
4), have still to be incorporated but this should not be too hard.
Extending the dictionary of terms and the corresponding library
of images will also be reasonably straightforward, utilising
Elvin's Dictionary of Heraldry and images available online
(Phillips). A much more difficult task will be to extend the
formal grammar to cope with a larger range of blazons. In any
language processing application the construction of a formal
grammar is usually the most time consuming part as textbooks
tend to define syntax informally or by means of examples.
Another difficult problem is the sensible handling of potential
ambiguities.
Figure 3: Queen's College Belfast
Figure 4: The Royal University of Ireland
When we turn to the inverse operation, the decomposition of
a picture into its components in order to derive the blazon, we
meet a different set of problems. As with all image processing applications, we have to remove noise before we can begin to
identify components. Having removed a component we must
then fill in the gap in the component that underlay it. We must
finally construct the blazon, taking care to introduce the
components in the right order and to conform to the standard
conventions of blazoning.
A partly successful example is shown below (Figure 5). Instead
of recognizing the background as per fess or and azure, it treats
each half as a fess, i.e. a horizontal band across the middle of
the shield. However it recognizes the diagonal bend sable. It
is, though, well on the way to establishing that the blazon is
Per fess or and azure a bend sable.
Figure 5: Stages in decomposing a coat of arms: colour separation, noise
reduction, shape filling and component identification
1. See Carswell; Stewart; McVicker; Tinman; Black; Carson; Nicholl;
McGuckin; O'Shea.
Bibliography
Black, Sarah-Jane. Heraldic Register and Ordinary. 2001.
(Student project.)
Burke, J.B. General Armory. Ramsbury, Wiltshire: Heraldry
Today, 1961, 4th impression 1989. Facsimile of The General
Armory of England, Scotland, Ireland, and Wales; comprising
a Registry of Armorial Bearings from the Earliest to the Present
Time by J. B. Burke (1842, last edition 1884).
Carson, Gayle. Coat of arms. 2002. (Student project.)
Carswell, T. Peter. Displaying coats of arms. 1988. (Student
project.)
Elvin, C.N. Dictionary of Heraldry. London: Heraldry Today,
1969, 2nd printing 1977. Facsimile of the original edition by
C. N. Elvin (1889).
Flanagan, Lorna. Shields software system. 1998. (Student
project.)
Foster, J. The Dictionary of Heraldry – Feudal Coats of Arms
and Pedigrees. With an introduction by J.P.B. Brooke-Little.
London: Bracken Books, 1989. Previously published as Some
Feudal Coats of Arms by Joseph Foster, published by James
Parker & Co. (1902).
McGuckin, Niall. A coats of arms editing package. 2003.
(Student project.)
McVicker, Stephen. The herald's editor. 1997. (Student
project.)
Nicholl, Paul R. Coats of arms. 2002. (Student project.)
O'Shea, Laura. Automated heraldic artistry. 2004. (Student
project.)
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introduction by J.P.B. Brooke-Little. London: Heraldry Today,
1985. Facsimile of An Alphabetical Dictionary of Coats of
Arms belonging to Families in Great Britain and Ireland;
forming an extensive Ordinary of British Armorials by J. W
Papworth & A. W. Morant, published by T. Richards (1874).
Phillips, D. Shareware clip art collection of heraldic charges.
Accessed 2005-02-28. <http://www.digiserve.com
/heraldry/gifart.exe>
Stewart, William. Displaying a coat of arms. 1993. (Student
project.)
Taylor, Simon. 3D maps. 2005. (Student project.)
Tinman, Richard. Blazoning arms. 2000. (Student project.)