Visual computation of surface lightness: Local contrast vs. frames of reference

Seeing black, white and gray surfaces, called lightness perception, might seem simple because white surfaces reflect 90% of the light they receive while black surfaces reflect only 3%, and the human retina is composed of light sensitive cells. The problem is that, because illumination varies from time to time and from place to place, any amount of light can be reflected from any shade of gray. Thus the amount of light reflected by an object, called luminance, says nothing about its lightness. Experts agree that the lightness of a surface can be computed only by using the surrounding context, but they disagree about how the context is used. We have tested an image in which two major classes of theory, contrast theories and frame-of-reference theories, make very different predictions regarding what gray shades will be seen by human observers. We show that when frame-of-reference is varied while contrast is held constant, lightness varies strongly. But when contrast is varied but frame-of-reference is held constant, little or no variation is seen. These results suggest that efforts to discover the exact algorithm by which the human visual system segments the image received by the retina into frames of reference should be given high priority

Where is the Xerox Corporation of the LIS Sector?

published or submitted for publicatio

Terminolojiye Aşırı Yüklenme

The information industry is now full of professionals from many areas, and those who have been working in that area the longest: that is to say, librarians, documentalists and information scientists, must learn the language that these other professions use it they are to maintain their own professionalism and work effectively (as they must) with the relative newcomers. The belief in the statement above is exemplified in the new use of the word taxonomy, and several meanings of this word are discussed with reference to findings from a research study conducted by the author.Bugün, enformasyon sanayiinde birçok alandan gelen profesyoneller ve bunların arasında bu alanda en çok emek vermiş olan kütüphaneciler, belge ve bilgi bilimciler, eğer kendi profesyonelliklerini sürdürmek ve göreceli olarak bu atana giren yeni kişilerle etkin bir şekilde çalışmak istiyorlarsa, diğer meslekte olanların dilini öğrenmelidirler. Yukarıda ifade edilen gerçek, "taksonomi" teriminin yeni kullanımına ilişkin bir örnek üzerinde anlatılmış ve yazar tarafından yapılmış olan bir araştırmanın bulgularına dayanarak, bu terimin çeşitli anlamları açıklanmıştır

Investigación académica y gobernanza ética: una perspectiva sobre la creación de información

Research ethics is briefly reviewed, both as being of potential interest to those conducting research in library or information science, and as a comparison with aspects of information ethics.Se revisa brevemente el problema de la ética de la investigación científica, tanto como un tema de in-terés potencial para las personas que llevan a cabo investigación en el campo de la ciencia de la información, como por sus relaciones con diversos aspectos de la ética de al información

La paradoja de la información

Personal thoughts on the varied practice and still unformed theory of information science. After some four decades of strong development of information handling practice, largely in support of the disciplines of science and technology, advances in the traditional areas of practice have slowed down as information technology has been more widely applied. Meanwhile, a true theory of information science has failed to materialize.Reflexiones personales sobre la situación actual y perspectivas futuras de la ciencia de la información, cuya práctica está muy extendida pero cuya teoría no se ha consolidado todavía. Tras varias décadas de fuerte desarrollo de las prácticas de gestión de la información, fundamentalmente como soporte de las disciplinas técnicas y científicas, los avances en las áreas tradicionales de actividad práctica se han ralentizado a medida que se generalizaba la aplicación de la tecnología de la información. Mientras tanto, no se ha materializado la aparición de una verdadera teoría de la ciencia de la información

Sobre las revoluciones y la revolución de la información

The so-called 'Information Revolution' is contrasted with the classical revolutions of agriculture and industry and found to be misleading because of the abstract nature of the word information. It is argued that in fact there is rather a Communications Revolution following on from a succession of prior and dramatic lesser revolutions in communication 'technologies'. At the moment, the new Communications Revolution is swamping the world with 'messages' that may or may not constitute meaningful information. It is speculated that the advent of social media and networking may eventually solve this problem of overload and make some sense out of the seeming chaos; and that there may still be a role for information scientists to play in this process.La denominada ‘revolución de la información’ es contrastada con las revoluciones clásicas de la agricultura y la industrialización; y se descubre que el concepto es confuso debido a la naturaleza abstracta del término información. Se arguye que, en realidad, se trata más bien de una revolución de las comunicaciones, construida sobre una sucesión de revoluciones previas y dramáticas en las tecnologías de la comunicación. En el momento actual, la nueva revolución de las comunicaciones está inundando el mundo con ‘mensajes’, que pueden o no constituir información significativa. Se especula que el advenimiento de los medios sociales y del trabajo en red puede finalmente resolver este problema de sobrecarga informativa y extraer algún sentido del caos aparente; y que todavía puede haber un papel que desempeñar para los científicos de la información en este proceso

De las tarjetas perforadas a Google: una historia esquemática de la ciencia de la información

This paper reviews the history of information re-trieval (IR) from punched cards and the first pro-grammable computer (the ENIAC of 1945) to the present day Web searcher Google and Microsoft’s “cognitive technology” Watson. The review is based on three major factors in the development of IR; (1) the enormous increase in computing power over the last 72 years, (2) the “competition” between statis-tical analysis of text and Natural Language Pro-cessing (NLP) in which the two have finally to a large extent converged, and (3) the corresponding changes in human intervention in the IR process.Se revisa la historia de la recuperación de información (IR) desde las tarjetas perforadas y la primera computadora programable (el ENIAC de 1945) hasta el actual buscador web Google y la “tecnología cognitiva” Watson de Microsoft. La revisión se basa en tres factores principales en el desarrollo de IR; (1) el enorme aumento en el poder de cómputo en los últimos 72 años, (2) la “competencia” entre el análisis estadístico del texto y el procesamiento del lenguaje natural (NLP) en la que ambos finalmente han convergido en gran medida, y (3) los cambios correspondientes en la intervención humana en el proceso de IR

Información sobre la información

This paper argues that though the information landscape has radically changed, the basic tenets of information science are still valid, are often unwittingly being applied and may again become more widely recognized. This new landscape is briefly illustrated with some selected examples of its size, dangers and current success stories. New models and approaches are beginning to emerge and some examples of these are presented. It is vital that these are encouraged and supported so that society and its citizens may become better informed.Se sostiene que, aunque el panorama de la información ha cambiado radicalmente, los principios básicos de la ciencia de la información siguen siendo válidos, y que a menudo indavertidamente siguien aplicándose, por lo que podrían volver a se de nuevo más ampliamente reconocidos. Este nuevo escenario se ilustra brevemente con algunos ejemplos seleccionados de su importancia, peligros e historias de éxito actuales. Están empezando a surgir nuevos modelos y enfoques, de los cuales se presentan algunos ejemplos. Es vital que sean alentados y apoyados para que la sociedad en su conjunto y, en particular, sus ciudadanos puedan estar mejor informados

"No saluda, sino que se ahoga": la Ciencia de la Información en la 'Sociedad de la Información"

While the contributions made by information scientists to tackling the explosion of electronic communications are both widespread and valuable much still needs to be done, particularly as the individual user of information is not only overwhelmed by the sheer quantity of information, but is increasingly subject to the posting of misinformation and even disinformation. At the same time, while the advantages of information technology are apparent there may be a danger that people will become increasingly prone to overuse, and even misuse it leading to a number of human problems. It is proposed that information scientists could take a more proactive role in tackling some of the problems caused by information overload.Las contribuciones de los científicos de la información frente a la explosión de las comunicaciones electrónicas siguen siendo intensas y valiosas, pero todavía queda mucho por hacer, especialmente en lo que se refiere al usuario individual de la información, que no sólo se siente abrumado por la enorme cantidad de información, sino que cada vez sufre mas la exposición a información errónea e incluso a la desinformación. Por otro lado, aunque las ventajas de la tecnología de la información son evidentes, se ha evidenciado el peligro de que las personas sean cada vez más propensas a su uso excesivo, e incluso a un mal uso que origine y acreciente diversos problemas humanos. Se propone que los científicos de la información tomen un papel más activo en la lucha contra algunos de los problemas causados por la sobrecarga de información

Changes in relative area produce equal and opposite effects on lightness and perceived illumination (Abstract only)

In prior work (Gilchrist & Soranzo, ECVP 2012) in which subjects looked into two windows in the far wall of a vision tunnel and adjusted the level of illumination in one window to match that of the othe, they matched the windows for highest luminance (not average). The fact that both lightness and perceived illumination are anchored by highest luminance directly implies Koffka’s invariance theorem. For a given luminance within a framework, changing highest luminance changes lightness and perceived illumination in equal but opposite ways. In this new study, we consider area effects. We found that when a darker region is less than half of the total area within a window, Koffka’s theorem applies directly. However, when the darker region covers more than half of total area, Koffka’s principle applies to the darker region, but not the lighter one, which is anchored at white. Perceived illumination level can now be incorporated systematically into anchoring theory