Learn More
Sensations of color show a strong correlation with reflectance, even though the amount of visible light reaching the eye depends on the product of reflectance and illumination. The visual system must achieve this remarkable result by a scheme that does not measure flux. Such a scheme is described as the basis of retinex theory. This theory assumes that(More)
Many different descriptions of retinex methods of lightness computation exist. This paper provides concise MATLAB implementations of two of the spatial techniques of making pixel comparisons. The code is presented along with test results on several images and a discussion of the results. The paper also discusses the calibration of input images and the(More)
Following Munsell's bisection procedure [J. Opt. Soc. Am. 23, 394 (1933)], we established a nine-step gray scale in which each step is an equal increment in lightness. We calculated retinal illuminances after intraocular scatter by using the point-spread function of Vos et al. [Vision Res. 16, 215-219 (1976)]. After this correction for intraocular scatter,(More)
As a part of the Symposium " Retinex at 40 " , this paper recounts the research on capturing real-life scenes, calculating appearances and rendering sensations on film, and other limited dynamic-range media. It describes: the first patents, a hardware display used in Land's Ives Medal Address in 1968, the first computer simulations using 20 by 24 pixel(More)
Protocol version 6 (IPv6) prototype for the Digital UNIX operating system. In this paper, we describe the design of the Digital UNIX IPv6 prototype and its history relevant to the Internet Protocol next generation (IPng) effort in the Internet Engineering Task Force (IETF). We also compare its relationship with the existing Transmission Control(More)
The number of cycles in a low-frequency sinusoidal display is a crucial variable in determining the visibility of the display. In particular, the threshold contrast is essentially independent of spatial frequency for these displays. We have extended the above experiments, using more cycles and a variety of targets and observer tasks. The results confirm(More)