Sidelights on visual texture (1994)

Abstracts Source: Leonardo, Vol. 27, No. 2, (1994), pp. 123-126 Published by: The MIT Press Stable URL: http://www.jstor.org/stable/1575979 Accessed: 13/08/2008 11:57 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=mitpress. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact support@jstor.org. http://www.jstor.org .^ TheAbstractssectionof Leonardo is intendedto bea rapidpublicationforum. Textscan beup to 750 wordsin lengthwith no illustrations,or up to 500 wordsin lengthwith one black-and-white illustration.Abstractsare acceptedfor publicationupon recommendation of any one memberof theLeonardo EditorialBoard, who will thenforward themto theMain Editorial Officewith his or herendorsement. SIDELIGHTSON VISUAL TEXTURE Jose Luis Caivano, Olaya 1167, 8 C, 1414 Buenos Aires, Argentina. Received3 May 1993. Acceptedfor publication byRogerE Malina. This article reports on a work that deepens the study of texture, a factor of visual perception whose development has generally received little attention from the analytical point of view [1]. Textures are considered here as visual signs, rather than as sensations of touch. The system I present includes methods for texture ordering, classification, description, notation and production. Its basic tools are a set of variables for analysis that can be quantitativelyexpressed or registered to provide specific notations. This set of variables allows the user to analyze simple textures, as well as to control their combination to obtain any degree of complexity. The variables aim at describing textures, and the numerical notation is a useful tool for easily transmitting information about textures without drawing them (for instance, in interaction with computer graphics). My previous work [2] led to the completion of a relatively simple system that allows for the organization, analysis and production of certain textures. Its main weakness is that it only produces absolutely regular textures and therefore does not account for the many irregular textures habitually encountered. The work I report on here overcomes this limitation and progresses into new fields. ? 1994 ISAST ^ FX9I w I classify textures primarily as simple or complex. In plain terms, simple textures are generated by the repetition and juxtaposition of an elementary pattern (called a texture unit), which is composed of two identical texturing elements separated by a certain interval. Complex textures are generated by the superposition of two or more simple textures. In order to analyze or define a simple texture, it is necessary first to describe the texturing element by means of a set of variables that account for its shape,and, secondly, to describe it by means of variables of proportionality,organization and density,which reflect the way texturing elements appear in the texture unit. Even though the shapeof the texturing elementdoes not alter the basic structure of the texture, undoubtedly it does modify its visual aspect. To analyze this variable, we may use the theory of spatial delimitation to describe simple or complex shapes [3]. is the variable that deProportionality fines the proportion (height/width) of the texture unit. Organizationis the variable that defines the relative position of the texturing elements within the texture unit. It relates the slope of the texturing elements' alignment to the proportionality of the texture unit. Densityis the variable that relates the surface of both texturing elements to the surface on which they appear. If, thinking in terms of the figure-ground phenomenon, we consider the texturing elements as figure, then density is the surface of figure divided by the surface of ground. Figure 1 shows four groups of simple textures, each with a single variation. Complex textures are those made up by the combination of simple textures. First, the combination of two simple textures needs to be considered. This involves the description of the simple textures plus the description of the combinatorial variables: separationon Fig. 1. Jose Luis Caivano, the four variables of simple two-dimensional textures: shape, organization, proportionality and density. Each column shows three sample textures where the given variable changes. The numbers below each texture constitute its notation. For instance, in the first texture (composed of triangles), 3/1 denotes the shape of the texturing element, 0.5 the organization, 1 the proportionality and 0.28 the density. Variation of Shape AAAAAAAAAAAA AAAAAAAAAAAA AAAAAAAAAA Variation of Organization Variation of Proportionality Variation of Density 4/1-0.5-2.25-0.28 4/1-0.5-1-1 4/1-0-10.2???8? AAAAAALAAAAAA AAAAAAA&AAAAA 3/1-0.5-1-0.28 4/1-0-1-0.28 mmmmmmmmmmmm me.mm.mmmmmm m.mm.m.mmumm mmmW 4/1-0.5-1-0.28 4/1-0.5-1-0.28 mmmmm. umm.mm.mmm.m on ummEmmmmmm mmmmmammmmmm 4/1-0.5-1-0.28 4/1-0.5-1-0.28 U **"" U UU"."U * K"U". *4/1-0.5-1-0.1098 U".".U 4101111111110 4/1l1 11- 10l. 4/4-0.5-1-0.28 4/1-1-1-0.28 4/1-0.5-0.44-0.28 LEONARDO, 4/J-0.5-1-o. Vol. 27, No. 2, pp. 123-126, 1994 loo 123 the x axis, separationon they axis and rotationexisting between both simple textures. Each variable can be expressed numerically. The juxtaposition of two simple textures produces a complex texture of the first grade. The procedure can be recursively applied in order to describe or generate complex textures of second, third or higher grades. For example, a second-grade complex texture is the combination of a first-grade complex texture with a simple texture (involving a total of three simple textures), a thirdgrade complex texture is the combination of two first-grade complex textures or the combination of a second- grade complex texture with a simple texture (involving a total of four simple textures), and so on. Some immediate consequences of this system are that textures can be thoroughly classified with sound criteria, and that it is conceivable to think in terms of the development of a system for ordering textures, just as color systems have been proposed for the organization of colors. This systematization would provide artists and designers with a basis for managing principles of harmony in the use of textures. References and Notes 1.J.L. Caivano, "Towardsan Order System for Visual Texture," forthcoming in LanguagesofDesign. 2. J. L. Caivano, "VisualTexture as a Semiotic System," Semiotica 80 Nos. 3/4, 239-252 (1990). 3. This theory has been proposed by C. Jannello. An English account of it may be found in C.F. Cuerri, "Architectural Design and Space Semiotics in Argentina," The SemioticWeb1987, T.A. Sebeok andJ. Uniker-Sebeok, eds. (Berlin: Mouton de Gruyter, 1988), pp. 389-419. BINARISATION PERFORMANCES:DIRECT INTERVENTIONON THE DIGITAL NETWORKS Bernard Demiaux, Centre de Binarisation, 4, Place de Seoul, 75014 Paris, France. Received10 September1993. Acceptedfor publicationbyRogerF Malina. Theory Experiments in digital transmission generally use the entire range of information-transfer techniques available in our era-involving both alternating and interactive exchange-without, however, revealing the specifics of the process. In comparison, information transfer 124 Abstract Fig. 2. Bernard Demiaux, front page for the XLV Venice Biennale. (IT) artistic action involves networks as channels of digital information, maintaining existing procedures of communication while applying a strategy of digital amplification using two variables: time and memory. * The time variable defines the frequencies of sending images according to time periods of 2, 4, 8 and 16 units; it defines methods of display according to line-by-line increments. The passage of time is heightened during the period of transmission. * The memory variable sends the digital content (0/1) of the transmitted fragments: the 0/1 elements that represent the structure of the fragment are sent as such through the lines of the network, and the message is then presented in binary form. The memory of the message is thus heightened during this time. The type of network chosen may be local or long-distance; the layer of reception of the binary fragments functions in the background in the communication software. Practice Following are analyses of two typical binarisation performances: CulturalSigns, created for the XLVVenice Biennale [1], and Memoryof the TwentiethCentury, which was part of Documenta IX [2]. CulturalSigns The objective of this performance was to broadcast through the Integrated Services Digital Network (ISDN) a multimedia IT journal on the theme of cultural signs. The following question was posed to correspondents connected to the network: "Define the meal, the cloth, the feast and the means of communication which, in your opinion, best express your culture." The network correspondents sent their messages by fax, mail or ISDN to the Binarisation Center in Paris. I converted the messages into binary code and transmitted them by ISDN line to Venice. The data were expressed in real time and integrated into the multimedia journal as they were binarised (see Fig. 2). Memoryof the TwentiethCentury The following question was posed to correspondents connected to the network: "Define the Man, the Woman, the Object and the Event which you feel best express the twentieth century in the human memory." The journal was relayed by radio waves throughout the zone of Kassel and the state of Hessen (Frankfurt). Hookups were assured by satellite transmission on the cable networks of Germany, Switzerland, Austria, Italy, France, the Commonwealth of Independent States (CIS), Japan, Canada and the United States. Binary messages were transmitted over a field of interactive communication called the "PiazzaVirtuale." The interactive-television experiment produced at Kassel by Van Gogh TV al-