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Cesia: A system of visual signs complementing color


Abstract and Figures

Color theory has been worked up by some researchers in order to consider factors such as transparence, brightness, opacity, etc., but no color order system has been devised to include these variables in addition to the usual three. This work proposes to treat these factors as theoretically separate from color (even if they are related with it), developing an order system for them. When it is taken parallel to color, this system helps to describe all the visual perceptions produced by light stimuli.
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Cesia: A System of Visual Signs
Complementing Color
José Luis Caivano
Volume 16, Number 4, August 1991
José Luis Caivano
Cesia: A System of Visual Signs
Complementing Color
Olaya 1167, 8° C
1414 Buenos Aires, Argentina
Color theory has been worked up by some researchers in
order to consider factors such as transparence, brightness,
opacity, etc., but no color order system has been devised
to include these variables in addition to the usual three.
This work proposes to treat these factors as theoretically
separate from color (even if they are related with it), de-
veloping an order system for them. When it is taken parallel
to color, this system helps to describe all the visual per-
ceptions produced by light stimuli.
Certain authors who have written about color theory have
been interested in some problems rising from the consid-
eration of the number and type of perceptual variables in-
volved in the definition of color. I am referring to those
henomena treated as variables, attributes, or modes of ap-
earance of color, such as brightness, brilliance, transpa
ency, luster, glossiness, etc., sometimes added to the three
normally considered: hue, value, and chroma.
As Evans tells us, the OSA Committee on Colorimetry
ublished a work in 1953 which-influenced by Katz’s cat-
egories— classifies the perception of color into five “Modes
of Appearance,” three “Attributes of Color Sensation,” and
eleven “Attributes of Modes of Appearance” (including the
three attributes of color sensation here).1 I quote the list as it
appears in Evans.2
Aperture (1-5)
Illuminant (1-8)
Illumination (1-3)
Object modes: Surface (1-11)
Volume (1-9)
1. Brightness (or lightness)
2. Hue
3. Saturation
258 CCC 0361-2317/91/040258-11 $4.00
4. Size
5. Shape
6. Location
7. Flicker
8. Sparkle
9. Transparency
10. Glossiness
11. Luster
In regard to the modes of appearance, the object modes,
surface and volume, do not produce, from my point of view,
any alteration of color characteristics. A color may be only
on the surface or it may fill the entire volume of an object,
but color itself does not change because of this. A square
(a surface) and a cube (a volume) are two different visual
forms; but a red color, whether it be over a surface or filling
a volume, is always a red.
In regard to the attributes of modes of appearance, size,
shape, and location are purely spatial perceptions, while
flicker and sparkle are temporal changes in the amount of
light, having nothing to do with color as a selective per-
ception of light spectrum. But what happens with transpar-
ency, glossiness, and luster?
Hesselgren, considering whether color is a sensation or
a perception, says
If transparency and lustre are included in the attributes
of colour, the latter must be regarded as a perception.
If, on the other hand, the attributes are restricted to
such qualities as lightness and hue, colour should be
regarded rather as a sensation. If such be the case,
transparency and lustre must be considered to be dif-
ferent modes of appearance and colour.3
Lustre, reflection, sparkle and glitter are other modes
of appearance of colour . . . They always occur on the
object but do not appear to belong to the local colour
of the object.4
Pope, who also recognizes that dealing with color he is
momentarily not concerned with position (attitude, interval),
measure, or shape of visual images, asserts that
COLOR research and application
Prior to the description of the specific system, I would like
to say something about its origins and the place it occupies
in a more general theory which involves the organization
of different visual signs.
The whole process that reached this development took
lace at the School of Architecture of Buenos Aires Uni-
versity, where, in the 1960s, César Jannello began research
on the field of vision. Influenced by the proposals of color
order systems, such as the ones formulated by Ostwald,
Munsell, and Pope, he thought of similar organizations for
visual texture11 and form (which he called more specifically
delimitation,12 and which Claudio Guerri recently labeled
as spatial delimitation13). The main efforts of Jannello were
on the spatial delimitation field, so much so that he was
able to propose, one year before his death, the foundations
for a theory of delimitation,14 a system which organizes the
spatial figures in a similar way as color systems organize
colors. Nevertheless, he did not lose sight of the other visual
categories, realizing also that phenomena such as brilliance,
transparency, opacity, translucency, specular reflection, etc.
were not explained by the classical theories of color. He
roposed to treat these categories as separable fro
first calling this treatment the study of brightness. But as
this term alludes only to one of the particular situations in
the field (that of the bright objects), later on he proposed
the name cesia for all the field.
This term may seem strange, and really it is. Jannello
realized that we do not have a generic term for these visual
erceptions, as we do for others. Yellow, red, blue, orange,
violet, green, etc. are said to be colors. Triangle, square,
entagon, circle, rhombus, parallelogram, te
rahedron, cube,
sphere, etc. are said to be spatial delimitations or forms.
But what word can involve the visual signs listed in the
aragraph above? Not finding a suitable one in any language,
or a Latin or Greek root to conform it, Jannello decided,
instead of creating an arbitrary term, to derive it from his
name: César.
Summarizing, he set the basis for a general theory of
design composed of the theories of spatial delimitation,
visual texture, color, and cesia.
It was my purpose, working in the research program
directed by Claudio Guerri since 1985,15 to develop the
aspects less studied in the —at that moment incomplete—
theory of design. I was first interested in the combinatorial
aspects of figures.16 Then I centered my attention on a new
system for visual texture,17 and on the development of cesia,
which, in Jannello’s proposal, existed only as a name in-
volving the mentioned aspects of brilliance, transparency,
The fact is that now we have a consistently structured
theory of pure design, developed over the years by means of
the collective efforts of various researchers working under
In order to define any tone accurately from the visual
or psychological point of view, it is only necessary to
state its hue and value and intensity (chroma); but the
two further factors, which I shall call purity and bril-
liance, must be considered if one is to possess a com-
lete understanding of the subject.5
Evans treats the subject extensively and deeply. I will
only quote some passages that are related with our concern
at this moment.
The Munsell system, like all others, is based on the
assumption that three perceptual variables are neces-
sary and sufficient to describe all possible colors . . . We
have found that three are not sufficient . . .6
I thus take the position that perceived color has five
separate variables: hue, saturation, brightness, light-
ness, and brilliance.7
[Brightness] is the variable chiefly affected by a change
in the amount of light.
[White] involves at least three concepts . . . These
are: (1) the absence of hue, (2) the absence of grayness,
and (3) the presence of diffusion that scatters the in-
cident light in all directions . . . The third is the per-
ception of a stimulus characteristic not related to color.9
We can make the following observations on these works:
(1) There is a general agreement on the fact that more
than the three usual variables are necessary to describe the
erception of visual signs produced by light falling on ob-
(2) In the mentioned works it is not completely clear
whether the added variables belong to color itself or they
are merely different modes of appearance of color, i.e., i
they produce a variation of color or not. For example, it is
normally assumed that shape, size, position; etc. of colored
surfaces somehow do affect the perception of color, but it
is only affected in an external manner which has nothing to
do with color itself. On the other hand, it is not clear in
those works, whether the same happens with brilliance,
transparency, luster, etc. Of course, this problem has to do
with the consideration of how broad or narrow is the mean-
ing assigned to the word color.
(3) We can note some confusion in the use of terms. For
example, Evans’ brightness seems to be used in the sense
of Munsell and Pope’s value. The term lightness is also
used with the same meaning, but this word has in Evans a
different significance. Evans’ brilliance is close, if not iden-
tical, to Pope’s purity, as Evans himself notes.10
I want to give support to the position that it is better to
leave color as defined by the three variables (hue, value,
chroma) and treat the other aspects as not belonging to color,
even if they are related to it. This means that we will need
to develop an explicative theory for those “noncolor” char-
I will show a possible solution to these controversial
themes by means of the description of a system which in-
volves and organizes the problematic categories or attri-
olume 16, Number 4, August 1991
butes. This system is closely related to color but can be
taken as independent of it. The system also establishes a
defined place for the meaning of most of the terms discussed.
= — .
i – re
= ——— .
= — .
= —— .
i – a
a common general paradigm or scientific research pro-
In regard to color theory, we accept and include in this
theory of pure design, as Jannello did, the Munsell system
(with respect to the variables hue, value, and chroma) and
the Pope solid (with respect to its external simple shape).
Here I will not discuss the disadvantages and benefits of
both systems; I only want to point out that due to the study
of cesia to treat those variables sometimes added in color
theory, this last subject can be redirected to the treatment
by means of the three classical variables.
In addition, not only color but the four subjects that make
up the theory of pure design are developed, as we will see
with cesia in this article, by means of three kinds of vari-
ables, which in all cases are conceptually comparable
throughout the four subjects and also with other subjects
not related to visual perception.19
Referring to cesia, we are dealing with the kind of visual
signs produced by the transformation in quantity and/or
spatial distribution of the luminous flux that reaches the eye
after being either absorbed or re-emitted by an object. It
also includes the extreme cases in which light does not suffer
any transformation at all (in the theoretical case of total
transparency) or in which no light is seen (in the theoretical
case of total absorption). Thus, cesia includes visual signs
such as brightness, brilliance, glossiness, luster, translu-
cency, specular reflectiveness, opacity, matte(ness?), dif-
fusivity, and also the mentioned transparency and absorp-
Let us consider from the physical point of view the pro-
cesses that light may follow when it falls over an object.20
Depending on the characteristics of that object, light may
so that the incident radiation does not emerge
from the surface or body in any visible way (it may be
transformed into another kind of energy such as heat but it
does not concern us since we are only interested in visible
radiation), or re-emitted so that there is visible radiation
emerging in any way. H it is re-emitted it may be:
(2) Transmitted, passing through the object so that in-
cident and emerging radiation are in opposite semispaces
divided by the object, or
so that incident and emerging
radiation are in the same semispace in relation to the object;
(3) Diffused or scattered in infinite directions, or re-emit-
ted regularly in only one direction so that the emerging ray
is as even and direct as the incident one.
These situations are graphically expressed in Fig. 1.
I do not consider the process of light refraction because
it is a deviation of light that mainly produces a visual al-
teration of the shape, and we are not dealing with this kind
of phenomena.
I have exemplified these possibilities by means of the
logic of using extreme situations in the three cases. But we
can observe that, in each possibility, both extremes can be
linked with a continuum of intermediate cases.
For example, the first situation may vary from a total
absorption to a total re-emission by means of intermediate
steps with partial percentages of absorption. I call it a vari-
ation of absorption.
The second situation may vary from absolutely permeable
to absolutely reflective by intermediate steps with partial
ercentages of permeability. I call it a variation of perme-
The third situation may vary from completely diffuse to
completely regular, with intermediate steps of partial per-
centages of diffusivity. I call it a variation of diffusivity.
As a result, the three perceptual variables or dimensions
of cesia are
Absorption, which refers to the proportion between the
quantity of luminous radiation absorbed and the quantity re-
emitted by a surface or body. The coefficient of absorption
is defined by the division between the absorbed flux and the
total incident one:
As the absorbed amount is the incident minus the re-emitted,
the same formula can be expressed
This dimension varies between two poles: totally absorb-
ent and totally re-emitting, the first being the case of an
absolutely black body which theoretically may absorb the
100% of the received radiation (A = 1), the second being the
case of the bodies which theoretically may re-emit all
the received radiation, i.e., with 0% of absorption (A = 0)
[Fig. 2(a)];
Permeability, which refers to the proportion between the
radiation transmitted or passing through a body and the
radiation being reflected by it, considering only the non-
absorbed radiation. The coefficient of permeability is de-
fined by the division between the transmitted flux and the
re-emitted one,
As the re-emitted flux is equal to the incident minus the
COLOR research and application
FIG. 1. Processes followed by light falling over objects.
This dimension varies between two poles: permeable and
reflective, the first being the case of transparent and trans-
lucent bodies in which theoretically the 100% of the non-
absorbed radiation passes through (P = 1), the second being
the case of specular, bright, and matte surfaces in which
the total amount of nonabsorbed radiation is reflected (0%
of permeability, or P = 0) [Fig. 2(b)];
Diffusivity, which refers to the way in which the non-
absorbed radiation is re-emitted, whether it be scattered in
infinite directions or re-emitted regularly in only one direc-
tion. The coefficient of diffusivity is obtained by the division
between the diffused flux and the re-emitted one:
D = — .
In a more complete formula,
= ——— .
i – a
This dimension varies between two poles: diffuse and
regular, the first being the case of translucent and matte
surfaces, where diffusivity is 100% (D = 1), the second
being the case of transparent and specular reflective sur-
faces, where diffusivity is 0% (D = 0) [Fig. 2(c)].
I can define now, in more exact terms, the characteristics
of surfaces or objects which produce various of the stimuli
for visual sensation of cesia. Thus, ideal matte is a 100%
reflective and diffuse surface; specular is 100% reflective
and regularly re-emitting; perfect translucent is 100%
ermeable and diffuse; transparent is 100% permeable and
regularly re-emitting. It is necessary to make clear that I
am defining ideal types; in practice, values which only ap-
roximate in different degrees to the 100% are verified. The
qualities of being bright, brilliant, glossy, lustrous, or other,
may be described as partially having one or another of the
mentioned characteristics. For example, bright is a reflective
surface which re-emits light rather more regularly than dif-
It is important to remark the difference between the stim-
uli that produce color sensation and those that are seen as
cesias. In the case of color, the stimulus depends on the
selection with respect to the wavelength of the radiation. In
the case of cesia, the stimulus is due to the way in which
the radiation is seen, regardless of its wavelength. In this
sense I take color with a narrow meaning. Note that this
coincides with the usual terminology in color. When we
speak of a certain color we can specify a light red or a dar
yellow, a pure vivid red or a grayish one. In these cases
the adjectives are thought as belonging to color properties,
to such a point that the language has individual words o
color names for some of those tones, e.g., pink, brown,
scarlet, terracotta, and others. This does not happen when
we speak of a transparent, matte, or brilliant color. In such
cases the color is thought to be the same and the different
FIG. 2. Variables of cesia. The numbers indicate the percentages in amounts of light radiation. a) Variation of absorption.
b) Variation of permeability. c) Variation of diffusivity.
olume 16, Number 4, August 1991 261
aspects tend to be seen as characteristics belonging to the
material but external to color.
Cesia is mainly a visual sensation; it is what we see apart
from color, form, and texture. We tend to understand it as
a property of a material, but we can note that the same
material under different conditions of observation presents
different cesias. For instance, a piece of glass seen from
the opposite side as the light is incident looks transparent,
but if we see it from the same side as the light is coming,
it behaves more like a mirror (being the specular reflection
intensified as we increase the angle of observation). Stan-
dard conditions of observation or measurement need to be
established to make cesia be a parameter of classification
of appearance of materials.
We can arrange the three variables of cesia in order to make
up a model, a conceptual structure which organizes in a
continuous way the totality of signs corresponding to the
stimuli of cesia. The model takes a three-dimensional solid
shape, where each point within it represents a different cesia.
While we could construct a maquette with direct samples
(for example pieces of glass, which is a very ductile material
for getting changes in cesia), in graphic representations we
are obliged to use diagrams like those in Fig. 2.
The construction of the solid is as follows:
The cesias with constant permeability are organized in
triangular planes where diffusivity and absorption vary. In
Fig. 3(a), the 100% of nonabsorbed light passes through
the material. This may seem confusing because of the fact
that we actually see in Fig. 3(a) different absolute amounts
of passing radiation. Let me explain this. The difference
between the incident radiation (which is taken to be the
100%) and the re-emitted or emerging one (whether it be
only one number or the sum of two different radiations) is
the absorbed amount. In spite of the different amounts of
absorption producing different absolute amounts of passing
radiation, in all the cases within this plane the total of
nonabsorbed radiation passes. It is in this sense that I say
that the permeability is 100% (see definition of permeability)
and that it remains constant for the whole plane. In Fig.
3(b) the 50% of nonabsorbed light passes, while the other
50% is reflected, thus, the permeability is constantly equal
to 50%. In Fig. 3(c) the total quantity of light is reflected,
thus, the permeability is equal to 0% in the whole plane.
These planes are only the two opposite cases and an inter-
mediate one. Permeability can vary continuously in per-
centages from 100% to 0%, or in coefficients from 1 to 0.
We can observe that there is a point common to all the
lanes of constant permeability. It is the total absorbent cesia
(at the lowest vertex of the triangles). Consequently,
it is possible to attach these planes at this point, and the
result is a sequence which produces a solid as in Fig. 4.
Within each plane of constant permeability, we find cesias
with constant absorption along horizontal lines [Fig. 5(a)]
and cesias with constant diffusivity along lines converging
to the point of total absorption [Fig. 5(b)].
If we take the horizontal lines of constant absorption for
all the planes of constant permeability (each line is at the
same distance from the vertex in the different planes), we
obtain horizontally curved planes, each one containing ces-
ias of constant absorption. Absorption also varies from 100%
(total absorption) to 0%, expressing it in percentages, or
from 1 to 0, expressing it is coefficients [Fig. 6(b)].
If we take the convergent lines of constant diffusivity for
all the planes of constant permeability (each line has the
same slope in the different planes), we obtain convergent
lanes, each one containing cesias of constant diffusivity.
Diffusivity also varies in percentages from 100% to 0%, or
in coefficients from 1 to 0 [Fig. 6(c)].
These two series of planes and the series of planes of
constant permeability [Fig. 6(a)] are the three corresponding
to the variables or dimensions adopted for the analysis of
With these three variables and their corresponding planes
of constancy in the solid, we can formulate certain rules for
selecting cesias if we want to keep some “calculated” har-
mony in the selection. This is important in design, in the
same way as the harmonic selection of colors, spatial de-
limitations, and textures is.
Considering for each one of the three dimensions of cesia
(permeability, absorption, and diffusivity) the possibility of
being constant (indicated by the sign +) or varying (indi-
cated by the sign –), we can make up a matrix of logical
relations, as shown in Fig. 7.
In the first case all the dimensions remain constant and
the possible selection which exemplifies this formula is a
repertory of identical cesias. This is the case if we take three
lanes of constancy (each one corresponding to one dimen-
sion) within the solid of cesia. The intersection of these three
lanes is a point, and in a point we have only one and the
same cesia [Fig. 8 (a)].
From the second to the fourth cases, we keep two di-
mensions constant while the third varies. The possible dif-
ferent formulas are three and the corresponding examples
of repertories of cesias are exemplified below each one in
Fig. 7. These are the cases if we take pairs of planes of
constancy within the solid. The intersections are lines, and
in a line we have a continuum of cesias, and only one
dimension varies [Fig. 8(b); see also Fig. 5].
From the fifth to the seventh cases we keep only one
dimension constant while the other two vary. Once again
we obtain three formulas and possible repertories (Fig. 7).
This is the case if we take cesias from individual planes of
constancy within the solid [Fig. 8(c)].
Finally, the eighth case is that in which the three dimen-
sions vary (Fig. 7). In this case we are selecting cesias
throughout the whole solid or in a three-dimensional space
within it [Figure 8(d)].
This matrix of logical relations was proposed at first by
Jannello for the selection of figures in the theory of spatial
COLOR research and application
FIG. 3. Development and variation of cesias within planes keeping constancy of permeability. a) Plane of constant permeability
(100% or 1). The small figure indicates approximately the place for transparent, translucent, and absorbent cesias. b) Plane
of constant permeability (50% or 0.5). c) Plane of constant permeability (0% or 0). The small figure indicates approximately
the place for specular, brilliant, bright, lustrous, glossy, matte, and absorbent cesias.
olume 16, Number 4, August 1991 263
FIG. 4. Solid of cesias: Horizontal projection and vertical ones from different points of view (A, B, C, D).
FIG. 5. Sequence of lines of constancy within a plane of constant permeability. a) Each line is the place for cesias with
constant absorption (and permeability). b) Each line is the place for cesias with constant diffusivity (and permeability).
FIG. 6. Sequence of planes of constancy within the solid. a) Each plane is the place for cesias with constant permeability.
b) Each plane is the place for cesias with constant absorption. c) Each plane is the place for cesias with constant diffusivity.
COLOR research and application
FIG. 7. Matrix of logical relations or the selection of cesias from the solid. Each formula indicates the dimensions remaining
constant (+) and varying (–).
FIG. 8. The eight logical relations exemplified in the solid by a point, lines, surfaces, or the whole volume. a) Intersection
of three planes. Selection of only one and the same cesia placed in a point (with three constant dimensions). b) Intersection
of two planes. Selection of cesias placed along lines (with two constant dimensions). c) Individual planes of constancy.
Selection of cesias placed on the corresponding surfaces (with one constant dimension). d) Selection of cesias from the whole
volume (with no constant dimension).
delimitation,21 and also used in order to control the har-
monies of color. In addition, I applied it to the selection of
configurations (groups of related figures) in spatial delim-
itation,22 to the selection of textures,23 and cesias.
The matrix sets the selections in an orderly manner, pro-
ducing harmonies going from the absolute constancy or
“monotony” (first formula) to the major possible variability
Volume 16, Number 4, August 1991
or “apparent chaos” (eighth formula). Even in this last case
we have a chance to produce harmonic selections (though
with a minor grade of constancy). Suppose we select cesias
and their three dimensions vary, but in equal or propor-
tionally progressive steps; this can be done by taking cesias
laced at distances which are based on a certain rule (equal
distances, distances in arithmetic or geometric progressions,
(matte) (specular)
0/0/1 0/0/0.75 0/0/0.5 0/0/0.25 0/0/0
0/0.25/1 0/0.25/0.66 0/0.25/0.33 0/0.25/0
0/0.5/1 0/0.5/0.5 0/0.5/0
0/0.75/1 0/0.75/0
/1/ Permeability = 0
0.25/0/1 0.25/0/0.75 0.25/0/0.5 0.25/0/0.25 0.25/0/0
0.25/0.25/1 0.25/0.25/0.66 0.25/0.25/0.33 0.25/0.25/0
0.25/0.5/1 0.25/0.5/0.5 0.25/0.5/0
0.25/0.75/1 0.25/0.75/0
/1/ Permeability = 0.25
0.5/0/1 0.5/0/0.75 0.5/0/0.5 0.5/0/0.25 0.5/0/0
0.5/0.25/1 0.5/0.25/0.66 0.5/0.25/0.33 0.5/0.25/0
0.5/0.5/1 0.5/0.5/0.5 0.5/0.5/0
0.5/0.75/1 0.5/0.75/0
/1/ Permeability = 0.5
0.75/0/1 0.75/0/0.75 0.75/0/0.5 0.75/0/0.25 0.75/0/0
0.75/0.25/1 0.75/0.25/0.66 0.75/0.25/0.33 0.75/0.25/0
0.75/0.5/1 0.75/0.5/0.5 0.75/0.5/0
0.75/0.75/1 0.75/0.75/0
/1/ Permeability = 0.75
(translucent) (transparent)
1/0/1/ 1/0/0.75 1/0/0.5 1/0/0.25 1/0/0
1/0.25/1 1/0.25/0.66 1/0.25/0.33 1/0.25/0
1/0.5/1 1/0.5/0.5 1/0.5/0
1/0.75/1 1/0.75/0
/1/ Permeability = 1
TABLE I. Notation system for cesias. Each formula expresses the coefficients of: Permeability/Absorption/Diffusivity.
Formulas are positioned in this table as cesias are in the solid (cf. Fig. 3).
266 COLOR research and application
etc.) within the solid. In such a case we obtain cesias which
vary following that rule, having certain grade of constancy
in the variation. The constancy (in this case) refers to the
steps or degrees in which the variation is produced.
Harmonic rules regarding cesia can be used in design
when selecting materials or specifying surface finishing of
1. The book by David Katz is Der Aufbau der Farbwelt, 1911. It has
been published in England as The World of Colour, Kegan, Paul,
Trench, Trubner, London, 1935. The book by the Optical Society o
America-Committee on Colorimetry is The Science of Color, Crowell,
New York, 1953.
2. Ralph M. Evans, The Perception of Color, Wiley, New York, 1974,
3. Sven Hesselgren, The Language of Architecture, Studentlitteratur,
Lund, Sweden, 1967, p. 50.
4. Ref. 3, p. 53.
5. Arthur Pope, The Language of Drawing and Painting, Harvard Uni-
versity Press, Cambridge, 1949, p. 28.
6. Ref. 2, p. 156.
7. Ref. 2, p. 94.
8. Ref. 2, p. 35.
9. Ref. 2, p. 86.
10. Ref. 2, p. 236.
11. César V. Jannello, Texture as a Visual Phenomenon, Archit. Des. 33,
394-396 (1963).
12. César V. Jannello, Fundamentos de Teoría de la Delimitación, FAU,
Universidad de Buenos Aires, 1984. Page citations in this article refe
to this Spanish edition. Also in French: “Fondemets pour une Théorie de
la Delimitation”, in Semiotic Theory and Practice: Proceedings o
the Third International Congress of the IASS (International Association
for Semiotic Studies), Palermo 1984, M. Herzfeld and L. Melazzo
(Eds.), Mouton de Gruyter, Berlin, 1988. The phrase “spatial delim-
itation” intends to avoid the polysemy of the word “form.” When this
last term refers to spatial shapes, or surfaces and volumes as defined
by their boundaries, both expressions can be used interchangeably.
13. Claudio F. Guerri, “Arquitectura, Diseño y Teoría de la Delimitación
Espacial,” paper presented at the I Coloquio Internacional Latino-
americano de Semiótica, Paris 1986. See also: “Aportes Sistemáticos a
una Teoría del Diseño,” in
roceedings of the Eleventh CLEFA,
Universidad de Morón, Argentina, 1985; and “Architectural Design,
and Space Semiotics in Argentina,” in
The Semiotic Web 1987,
T. A.
This system is proposed to be used either by means of visual
estimation of the variables, or by measure and determination
of the corresponding coefficients of permeability, absorp-
tion, and diffusivity for a given material under specified
conditions. It may be of benefit for the designer who need
to specify a determined visual appearance, to have an atlas
of cesias (which is yet to be materially constructed) as ref-
erence for visual matching. Furthermore, he can use a no-
tation involving the coefficients of the three variables.
Table I shows the notation system for cesias by means
of the values of Permeability / Absorption / Diffusivity. The
table is arranged according to the atlas in planes of constant
ermeability. Planes of permeability = 0.25 and perme-
ability = 0.75 have been added in relation to Fig. 3. How-
ever, this notation defines cesias independently from ref-
erence to the position of cesias in the atlas, i.e., we do not
need to know the position to have an idea of what the formula
is expressing. This does not happen with Munsell notation
for color, where numbers assigned to hue, value, and chroma
are a convention regarding the position of colors in the
By means of this system —besides color, texture, and spatial
delimitation systems— visual characteristics of designed
roducts may be consciously controlled using predetermined
harmonic rules. Different materials, such as plastics, glass,
metals (which may cover a certain range of cesias) might
be industrially produced to offer orderly and homogeneous
sets of cesias.
The notation may have useful applications. As words to
designate cesia sensations are scarce and ambiguous in most
cases, specification of visual qualities is facilitated by the
notation. It provides a different and univocal simple formula
for each of the infinite cesias. This may be used also in
industry to set specific tolerances.
Artists and designers may feel that systems of this kind
work against spontaneity, freedom, or inspiration. This is
a completely erroneous way of thinking. A system like
this, the color systems, or the similar ones for spatial de-
limitation or texture, contain, at least in abstract, the
complete universe of possibilities. The theoretical models
or solids contain all the signs we can use. The matrix of
logical relations considers all the selections we can make;
there is no one which does not fall into one of the for-
mulas. In addition, for spatial delimitation we have de-
veloped a model organizing all the possible combinations
Volume 16, Number 4, August 1991
between two figures.25 In this sense these systems do no
restrict freedom; all the choices are there. There is noth-
ing to lose knowing them and, on the other hand, there is
something to gain: the more we know the more our min
is open to new possibilities. Thus, inspiration may be
stimulated to increase.
In regard not only to cesia, but to the four visual systems
of the theory of pure design and their relations, I take the
in two groups depending on some common features:
Color and cesia, on one hand, concern mainly the per-
ception of light. Even if they need space (a surface or a
volume) to be developed, spatial changes do not affect the
intrinsically. Spatial delimitation and texture, on the othe
hand, concern mainly the perception of space. Their vari-
ables or dimensions have necessity of space in order to be
developed. Even if they need light to be seen, light does
not produce intrinsic changes onto them.
Color and cesia are purely visual categories. We canno
erceive them by means of any other sense. Spatial deli
itation and texture may also be, when presented volumet-
rically, perceived by touch.
Nevertheless, these four categories may be thought of as
eing the ones which are combined in order to make up ou
visual perception of the world. In semiotic terms, they are
the signs by means of which we are visually connected with
the external world.
Sebeok and J. Umiker-Sebeok (Eds.), Mouton de Gruyter, Berlin,
1988, pp. 389-419.
14. Ref. 12.
15. The objective (and also the title) of the research program is the elab-
oration of a knowledge for the construction of systems of norms, fo
teaching and projective practice, in the field of architecture, graphic,
and industrial design. It is carried out in the Secretaria de Investigación
y Posgrado at the Facultad de Arquitectura. Diseño y Urbanismo o
the Universidad de Buenos Aires.
16. José Luis Caivano and Claudio F. Guerri. “Arquitectura, Diseño
y Teoría de la Delimitación Espacial,” paper presented at the I
Congreso de la Asociación Argentina de Semiótica, La Plata, 1986.
17. José Luis Caivano, “Visual Texture as a Semiotic System,” Semiotica
(Journal of the IASS) 80-3/4, 239-252 (1990).
18. I have to mention also Ruben A. Gramón. Martín Fernández Meijide,
Liliana Gutiérrez, Ladys Baldelli, among others.
19. José Luis Caivano, “Coincidences in the Syntactics of Diverse Systems
of Signs Used In Architecture, Visual Arts, and Music,” paper pre-
sented at the Fourteenth Meeting of the Semiotic Society of America,
Indianapolis, 1989. In Semiotics 1989 (proceedings of the meeting),
J. Deely, K. Haworth, and T. Prewitt (Eds.), University Press o
America, Lanham, 1990, pp. 175-184.
20. I am indebted to Roberto Daniel Lozano, whose suggestions induced
me to adjust the terminology. His book, El Color y
u Medición,
Americalee, Buenos Aires, 1978, is perhaps the most complete one
published in Spanish on the science of color.
21. Ref. 12, p. 5.
22. Ref. 16, p. 13.
23. Ref. 17, p. 248.
24. Albert H. Munsell, A Color Notation, 1905, Munsell Color Company,
Baltimore, Maryland, 1946, pp. 20-22.
25. Ref. 16, pp 4-5, 10-13.
Received February 2, 1990; accepted November 26, 1990.
COLOR research and application
... Some closely related factors could be grouped together, for instance, Colour perception was intertwined with surface material, texture and also glossiness level [22], [23] Therefore, similar to the LESO-QSV [24] and AIQ-model [18], colour was grouped together with material, texture and surface glossiness in the 'materiality' category. Size, shape and position are grouped into 'geometry' category while joints and dummy elements are categorized into 'details' group (Table III). ...
Conference Paper
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There is a growing demand to utilize building faç ade areas for installing photovoltaics (PVs) and producing more clean energy. To support the faç ade integration of PVs in the urban context, this study proposed a series of evaluation criteria from an environmental aesthetic perspective. Fundamental environmental aesthetic theories were reviewed and Canter's 'sense of place' theory, Kaplan's cognitive preference model and Nasar's six positive qualities in built environment were selected as theoretical reference for this study. In addition, a literature search including aesthetic studies for building integrated PVs and solar systems was conducted. Based on the findings, relevant aesthetic factors were grouped in two levels (i.e. urban context level and building faç ade level). A set of new aesthetic evaluation criteria is proposed for both levels, covering both perceived physical aspects and conceptual aspects. Colour, surface texture and glossiness are suggested as key factors for further investigation. Keywords: Façade integrated PVs; urban context; environmental aesthetics; aesthetic evaluation criteria
... transparent vs opaque, glossy vs matte, and light vs dark. 1,2 Objects may produce different spatial distributions of light, and this constitutes the stimulus for the perception of cesia. A diffuse light reflection of an opaque object normally produces a matte appearance. ...
Full-text available
Two questions are mainly discussed in this article: (a) how the shape of color order systems is related to different types of chromatic mixtures, and (b) how the opacity or transparency (an aspect of cesia) of the coloring media involved in the mixtures define the results, beyond the established categories of additive, partitive, and subtractive mixtures. The degree of transparency, translucency, or opacity of the material used certainly has a great influence on these processes and in the results obtained, and we could also think that the degree of gloss or matte finish of the surfaces affects the mixtures as well. The underlying idea is that these processes are of a gradualist nature, and that a continuous sequence can be traced between two poles: additive mixture of overlapping lights, on one side, and subtractive mixture of transparent color layers, on the other one. Thus, instead of just three separate or unconnected types of color mixtures, we can postulate a model based upon a gradual sequence between additive and subtractive mixture, with partitive mixture as one of the steps in between. A schematic 3D model of gradual transformation is proposed to encompass different color systems that represent any possible mixture between additive and subtractive.
... The concept of visual appearance includes categories such as colour, texture and cesia (seeCaivano 1991Caivano , 1994Caivano , 1996, among others. ...
Conference Paper
Full-text available
A gradualist perspective allows to explain many aspects of colour and visual appearance in a more appropriate way than the usual conceptions based on taxonomic divisions and categorial oppositions. We will deal with various problems associated with colour and appearance taking into account —rather than the usual oppositions, divisions, categories or taxonomies— the moments of transition, gradations and transformations that allow moving from one category to another, with a better understanding of how the relationships are produced and the ways in which those differences occur.
... A physical view of the food products not only stands for the chromatic distribution and shininess but also the transparency to the spatial distribution of light and glow has similar effects on the appearance. The luminosity of light creates the visual sensitiveness of the colour of the food and this visual perception due to varying spatial distribution of light is termed as "cesia" by the architect Cesar Janello in 1965 [75][76][77][78]. The chromatic distribution pattern defines the colour of the food by means of hue, saturation and luminosity which has been further alleged by cesia as permeability, darkness and diffusivity for the vividness and sharpness of the image in case of generating human visualization by transmission and reflection [78]. ...
Water can be classified differently on the basis of their surrounding environment and bonding attributes. Both free and bound water contributes in the changes during their removal from food materials. Different amount of energy and time is required to remove specific type of water. For example, bound water needs more energy and time in order to migrate from food materials. Similarly, higher cost and quality changes are associated with the removal of bound water at different food processing. However, a critical moisture content should be precisely maintained for prolonged shelf life as well as to keep maintaining expected texture, softness, crispness of foods during dehydration. In this chapter, the significance of the bound water removal from food has been critically discussed.
... La cesía es también una sensación visual. A partir de cómo se distribuye la radiación luminosa alrededor de los objetos en términos espaciales (radiación que además de ser absorbida por los objetos o superficies puede reflejarse o transmitirse, ya sea en forma regular o difusa), y a partir del contexto visual en que ello ocurre, los seres humanos obtienen y procesan sensaciones de transparencia, traslucencia, opacidad mate, apariencia espejada, brillo, etc. (Caivano 1991(Caivano , 1994. ...
... Usually, it is practical to divide the study of any system of signs into syntactics, semantics, and pragmatics. The syntactic aspects of cesia, those that refer to the relations of signs to one another, have already been developed in previous research, where the sensations of cesia were organized in a threedimensional model (in the fashion of color order systems), and procedures for the production of harmonies of cesia and the construction of scales of cesia were indicated (Caivano 1991(Caivano , 1994(Caivano , 1996. I want to address now some semantic and pragmatic implications of cesia, that is, referred to the relation of the signs of cesia to the objects they can represent, as regards semantics, and the relation of cesias to the interpreters of these signs, to whom they bring some kind of information, as regards pragmatics. ...
Full-text available
Cesia is the name adopted to designate the aspect of vision that has to do with the perception of different spatial distributions of light. Light interacts with objects and it can be absorbed, reflected or transmitted; in turn, reflection and transmission may occur regularly or diffusely. These are physical matters. Now on, the human visual system perceives this decoding and interpreting it as visual signs that carry information about certain qualities of the objects around: level of lightness or darkness, degree of opacity, glossiness, transparency, translucency, matt quality, etc. This kind of visual percepts are the ones just covered by the generic name cesia. Semiotics is the study of semiosis, that is, the processes of signification. We talk of semiosis when we are in front of situations where a transmission or exchange of information, a physical reaction, or an effect of meaning is produced by means of signs that act as agent between an object and a subject, serving to that subject as a representation of the object. Visual semiotics is the study of those processes where signs working in the visual channel are at play. Here, we are concerned with a certain kind of visual semiosis, the one where signs are given exclusively by different spatial distributions of light, cesias. Cesias are, thus, a special type of visual signs, other than color, visual texture, shape, or any other quality of the objects seized by the visual sense.
... These are physical matters that the human visual system perceive, decode and interpret as visual signs carrying information about certain qualities of the objects around: level of lightness or darkness, degree of opacity, gloss, transparency, translucency, matt quality, etc. These visual aspects have been encompassed under the generic term "cesia" [6][7][8]. ...
Full-text available
As a visual sign, a photographic image usually represents an object or a scene; this is the habitual way of seeing it. But it accomplishes that common semiotic task by representing various formal features of the object or scene: its color, shape, texture and spatial distribution of light. The curious fact is that photography does this in very different ways. With respect to color, a pigmented object produces a certain spectral distribution of light, and an ordinary photograph of that object causes approximately the same spectral distribution. The pigmented emulsions of the photographic paper act upon light in the same way as the pigmentation of the objects. In this sense, photography represents color by sharing physical properties with the objects. In truth, instead of representing color, it reproduces color. We have an indexical aspect of photography here (an index being a sign that is physically connected to the object that it represents). This is quite different from what occurs with the representation of the spatial distributions of light (transparency, translucency, mirror-like appearance, gloss, matt quality, etc.) by photography. A glass of water is a physically transparent object that generates the visual sensation of transparency, but a photograph of that glass, being an opaque object in itself (the substratum is an opaque piece of paper), also conveys the sensation of transparency. Summing up, photography represents the spatial distributions of light not by sharing physical features with the objects, but by means of a transformation that brings about a certain kind of similarity. In this sense, we could speak of iconicity (an icon being a sign that refers to its object by means of some kind of similarity with it). This paper will present a survey of these and other semiotic categories involved in photography when representing color and the perceived spatial distributions of light.
... It is usual to consider that the first two The word "cesia" has been coined to refer to the visual sensations produced by the different spatial distributions of light (sensations of transparency, translucency, matteness, specular reflection, glossiness, etc.), establishing a different domain with respect to the term "color", which designates all that has to do with the sensations originated by differences in the spectral distribution of light [2; 3; 4]. In the publications of reference (especially in [2] and [4]), antecedents on the study of related questions by authors such as KATZ, EVANS, POPE, HESSELGREN, HUNTER, and others are discussed. There, the interested reader can also find an explanation of how the word "cesia" was conceived. ...
Full-text available
The word “cesia” has been coined to refer to the visual sensations aroused by different spatial distributions of light: sensations of transparency, translucency, matte opacity, specularity, gloss, darkness, etc. The trichromatic theory holds that the perception of colors is possible through three kinds of receptors in the retina, sensitive to specific portions of the visible radiation: long wavelength, medium wavelength, and short wavelength; and the science of color has proved that by mixing appropriate amounts of three primary lights all the other colors can be produced. But color sensations are always accompanied by sensations of cesia; the same opaque color may have a glossy or matte aspect, a specular reflectance (mirrorlike appearance) may be colorless or colored, and we can also see color in transparency. Cesia stimuli appear associated with color due to the fact that all the spatial modalities of light transfer may be selective as regards wavelength; if they are nonselective, then we have achromatic or colorless cesias. The explanation arises from the analysis of the possibilities of transmission and reflection (whether they are diffuse or regular), as well as absorption of light, splitting the light stimuli into each primary component.
... "Cesía" es una palabra acuñada por César Jannello que se refiere a las sensaciones visuales producidas por las distintas formas de distribución espacial de la luz (sensaciones de transpa-rencia, traslucencia, mate, reflexión especular, brillo, etc.), a diferencia del término "color", que designa todo lo que tiene que ver con las sensaciones originadas por diferencias en la distribución espectral de la luz (Caivano 1991(Caivano , 1992 En el modelo desarrollado para el ordenamiento de las sensaciones de cesía tenemos cinco vértices ocupados por lo que se ha definido como cesías primarias: la especularidad (producida por una reflexión regular o especular), la cualidad de mate (producida por una reflexión difusa), la transparencia (producida por una transmisión regular), la traslucencia (producida por una transmisión difusa) y la sensación de negrura u oscuridad total (producida por una absorción de radiación visible). Las cuatro primeras se ubican en los vértices de una superficie cuadrangular y la última en un vértice inferior al que confluyen los cuatro anteriores, formando una especie de pirámide invertida (Figura 2). ...
Full-text available
"Cesía" es una palabra acuñada por César Jannello, que se refiere a las sensaciones visuales producidas por las distintas formas de distribución espacial de la luz (sensaciones de transparencia, traslucencia, mate, reflexión especular, brillo, absorción, etc.), a diferencia del término "color", que designa todo lo que tiene que ver con la distribución espectral de la luz. La teoría tricromática plantea que la percepción de los colores para los humanos (y para algunos otros mamíferos) se da a través de tres tipos de receptores sensibles a bandas específicas de longitudes de onda de la radiación luminosa: radiaciones de onda larga (excitando la sensación del rojo), de onda media (excitando la sensación del verde) y de onda corta (excitando la sensación del azul violáceo). La ciencia del color ha probado que mediante la mezcla en distintas proporciones de tres luces primarias solamente -una roja, una verde y una azul (mezcla que se conoce como síntesis aditiva)- se pueden producir todas las sensaciones posibles de color. Ahora bien, las sensaciones de color se presentan siempre asociadas a sensaciones de cesía. Un mismo color opaco puede presentarse con un aspecto brillante o con un aspecto mate. La reflexión especular, puede darse como algo incoloro pero también puede aparecer coloreada. Podemos ver asimismo color en la transparencia (como por ejemplo en vidrios coloreados o en filtros de color) y en la traslucencia. Todo ello es explicable mediante el razonamiento de que los estímulos de cesía aparecen asociados al color debido a que la transmisión, reflexión o absorción de luz puede darse de manera selectiva respecto de las longitudes de onda. Por otro lado, si la reflexión, transmisión o absorción de luz por parte de los objetos no se da en forma selectiva, sino que es igual para todo el espectro de la radiación visible, entonces obtenemos sensaciones de cesía acromáticas o incoloras. La explicación surgirá del análisis de las posibilidades de reflexión, transmisión y absorción, sea de manera difusa o regular, descomponiendo los estímulos luminosos en cada una de las componentes primarias (roja, verde y azul).
Full-text available
Se plantea cómo organizar los distintos aspectos de la cesía en función del análisis semiótico. El tipo de signos visuales que denominamos "cesía" es la representación e interpretación que el sistema visual humano hace de las diferentes modalidades de distribución espacial de la luz. Por un lado tenemos un fenómeno físico: la radiación visible y la forma en que interactúa físicamente con los objetos, produciendo luz difusa o regular, transmitida o reflejada, y sus combinaciones. Por otro lado tenemos un fenómeno perceptual: una sensación visual, producto de aquel estímulo físico, y una inferencia cognitiva, lo cual genera la percepción de traslucencia, transparencia, opacidad mate y brillo especular, con todos sus grados intermedios. Ambos aspectos por separado, el físico y el perceptual, producen semiosis en sus respectivos niveles: en el primer caso en el ámbito de la fisiosemiosis (entre hechos físicos) y en el segundo en el de la semiosis cognitiva (entre representaciones sensoriales y conocimiento). La conexión entre el aspecto físico y el perceptual podríamos ubicarla dentro del estudio de la biosemiosis, es decir cómo un dispositivo biológico particular, como es el sistema de visión, interpreta ciertos hechos físicos del mundo, obteniendo información útil para la supervivencia o el desenvolvimiento en el medio ambiente del animal al que este sistema de visión sirve.
paper presented at the I Coloquio Internacional Latinoamericano de Semiótica
  • Claudio F Guerri
Claudio F. Guerri, "Arquitectura, Diseño y Teoría de la Delimitación Espacial," paper presented at the I Coloquio Internacional Latinoamericano de Semiótica, Paris 1986. See also: "Aportes Sistemáticos a una Teoría del Diseño," in Proceedings of the Eleventh CLEFA, Universidad de Morón, Argentina, 1985; and "Architectural Design, and Space Semiotics in Argentina," in The Semiotic Web 1987, T. A.
Texture as a Visual Phenomenon
  • V César
  • Jannello
César V. Jannello, Texture as a Visual Phenomenon, Archit. Des. 33, 394-396 (1963).
Arquitectura, Diseño y Teoría de la Delimitación Espacial," paper presented at the I Congreso de la Asociación Argentina de Semiótica
  • José Luis Caivano
  • Claudio F Guerri
José Luis Caivano and Claudio F. Guerri. "Arquitectura, Diseño y Teoría de la Delimitación Espacial," paper presented at the I Congreso de la Asociación Argentina de Semiótica, La Plata, 1986.
The Language of Architecture
  • Sven Hesselgren
Sven Hesselgren, The Language of Architecture, Studentlitteratur, Lund, Sweden, 1967, p. 50.