The CIELAB color space, also referred to as L*a*b* , is a color space defined by the International Commission on Illumination (abbreviated CIE) in 1976. (Referring to CIELAB as "Lab" without asterisks should be avoided to prevent confusion with Hunter Lab). It expresses color as three values: L* for perceptual lightness and a* and b* for the four unique colors of human vision: red, green, blue and yellow. CIELAB was intended as a perceptually uniform space, where a given numerical change corresponds to a similar perceived change in color. While the LAB space is not truly perceptually uniform, it nevertheless is useful in industry for detecting small differences in color. Like the CIEXYZ space it derives from, CIELAB colorspace is a device-independent, "standard observer" model. The colors it defines are not relative to any particular device such as a computer monitor or a printer, but instead relate to the CIE standard observer which is an averaging of the results of color matching experiments under laboratory conditions. The CIELAB space is three-dimensional and covers the entire gamut (range) of human color perception. It is based on the opponent color model of human vision, where red and green form an opponent pair and blue and yellow form an opponent pair. The lightness value, L*, also referred to as "Lstar," defines black at 0 and white at 100. The a* axis is relative to the green–red opponent colors, with negative values toward green and positive values toward red. The b* axis represents the blue–yellow opponents, with negative numbers toward blue and positive toward yellow. The a* and b* axes are unbounded and depending on the reference white they can easily exceed ±150 to cover the human gamut. Nevertheless, software implementations often clamp these values for practical reasons. For instance, if integer math is being used it is common to clamp a* and b* in the range of −128 to 127. CIELAB is calculated relative to a reference white, for which the CIE recommends the use of CIE Standard illuminant D65. D65 is used in the vast majority industries and applications, with the notable exception being the printing industry which uses D50. The International Color Consortium largely supports the printing industry and uses D50 with either CIEXYZ or CIELAB in the Profile Connection Space, for v2 and v4 ICC profiles. While the intention behind CIELAB was to create a space that was more perceptually uniform than CIEXYZ using only a simple formula, CIELAB is known to lack perceptual uniformity, particularly in the area of blue hues. The lightness value, L* in CIELAB is calculated using the cube root of the relative luminance with an offset near black. This results in an effective power curve with an exponent of approximately 0.43 which represents the human eye's response to light under daylight (photopic) conditions. (Wikipedia).
Colourful in Theory - That Irks Me
Facebook: https://www.facebook.com/frameofessence Twitter: https://twitter.com/frameofessence YouTube: https://www.youtube.com/user/frameofessence Normal colour displays have 3 differently-coloured sub-pixels (red, green and blue). What happens if we add a yellow one into the mix? Corr
From playlist That Irks Me
Color Quantization (almost) done! -- Watch live at https://www.twitch.tv/simuleios
From playlist Space trees and stuff
Just finishing up the color quantization visualization. It's mostly done now. -- Watch live at https://www.twitch.tv/simuleios
From playlist Space trees and stuff
Covariant Phase Space with Boundaries - Daniel Harlow
More videos on http://video.ias.edu
From playlist Natural Sciences
Revel in some of the highest resolution images from the Hubble Space Telescope. Experience anew the detail in these inspiring images, snatched from distant galaxies, exploding stars, brilliant gas clouds, and black holes.
From playlist SpaceRip 4K
Stars of Cepheus as Seen by NASA's Spitzer Space Telescope
Soar through this cosmic landscape filled with bright nebulas, as well as runaway, massive and young stars. The image comes from NASA's Spitzer Space Telescope, which sees the universe in infrared light. For more about Spitzer, visit https://www.nasa.gov/spitzer or http://www.spitzer.calte
From playlist Spitzer Space Telescope
Pink doesn't exist! Tweet it - http://bit.ly/panYYg Facebook it - http://on.fb.me/nxhind minutephysics is now on Google+ - http://bit.ly/qzEwc6 And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in phy
From playlist MinutePhysics
Image Processing Accomplis Complex Objectives with High Level Functions
Speaker: Markus van Almsick The Wolfram Language continuously expands and improves high-level image processing and analyzing functions from image foreground and background separation to collage creation and color processing. This presentation demonstrates how to complete complex tasks qui
From playlist Wolfram Virtual Conference 2014
Styling on the web has been moving fast, bringing rich features for container-based styles and layouts, managing color contrast, leveraging device vibrant colors, gradients, and new color spaces for mixing, orchestrating stylesheets, subgrid, inert, :has() selector, and much more. With ea
From playlist Web Design: CSS / SVG
Marc Levoy - Lectures on Digital Photography - Lecture 13 (04May16).mp4
This is one of 18 videos representing lectures on digital photography, from a version of my Stanford course CS 178 that was recorded at Google in Spring 2016. A web site that includes all 18 videos, my slides, and the course schedule, applets, and assignments is http://sites.google.com/sit
From playlist Stanford: Digital Photography with Marc Levoy | CosmoLearning Computer Science
The Amazing Math behind Colors!
In this video, I talk about the math and science of colors for 42 minutes. Topics include cone cell response functions, electromagnetic radiation, spectral colors, luminance, color spaces, parametric equations, normal curves, mono and polychromatic light, emission spectra, spectral power
From playlist Summer of Math Exposition 2 videos
Generating Your Color Palette in CSS
In this video, Surma and Jake pick up the topic of Color Spaces again, because there’s more to talk about. Device capabilities, perceptually uniform color spaces, color mixing and contrast calculations. And all of that is coming to CSS! PUBLICATION PERMISSIONS: Original video was publishe
From playlist Web Design: CSS / SVG
Porque não conseguimos ver para além das três dimensões — Rogério Martins — ICM2018
Portuguese mathematician Rogério Martins is a professor at the University of Lisbon. He is a well-known researcher in Differential Equations and Dynamical Systems. Martins is also the presenter and mastermind of “Isto é Matemática” ("This is Mathematics"), a TV show for the dissemination
From playlist Public Lectures
OpenGL - gamma correction, HDR tone mapping, bloom
https://www.youtube.com/playlist?list=PLIbUZ3URbL0ESKHrvzXuHjrcLi7gxhBby Code samples derived from work by Joey de Vries, @joeydevries, author of https://learnopengl.com/ All code samples, unless explicitly stated otherwise, are licensed under the terms of the CC BY-NC 4.0 license as pub
From playlist OpenGL
To learn more about Wolfram Technology Conference, please visit: https://www.wolfram.com/events/technology-conference/ Speaker: Giulio Alessandrini Wolfram developers and colleagues discussed the latest in innovative technologies for cloud computing, interactive deployment, mobile device
From playlist Wolfram Technology Conference 2018
Topological Analysis of Grain Boundaries - Srikanth Patala
Srikanth Patala Masachusetts Institute of Technology February 1, 2011 GEOMETRY AND CELL COMPLEXES Polycrystalline materials, such as metals, ceramics and geological materials, are aggregates of single-crystal grains that are held together by highly defective boundaries. The structure of g
From playlist Mathematics
White Holes: An Impossible Possibility
Reid Reimers expands your mind with an explanation of white holes -- celestial objects that almost definitely are not real things that can be found in nature. Except, we might have actually seen one. ---------- Like SciShow? Want to help support us, and also get things to put on your wall
From playlist SciShow Space
Quantum Physics and Universal Beauty - with Frank Wilczek
How simple questions inspired Nobel laureate Frank Wilczek’s groundbreaking work in quantum physics. Subscribe for regular science videos: http://bit.ly/RiSubscRibe Frank's book "A Beautiful Question: Finding Nature's Deep Design" is available to purchase now - https://geni.us/Cz75S63 No
From playlist Ri Talks