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SUMMARY:What can we see on a high-dynamic range display? - Minjung Kim (Un
 iversity of Cambridge)
DTSTART:20200203T140000Z
DTEND:20200203T150000Z
UID:TALK139393@talks.cam.ac.uk
CONTACT:65221
DESCRIPTION:A typical computer or smartphone display has a luminance of 20
 0 cd/m2. By comparison\, high-dynamic range (HDR) displays have luminance 
 of 1000 cd/m2 or even 10\,000 cd/m2\, the brightness of the sky on a sunny
  day. However\, little is known about how to efficiently encode visual inf
 ormation at such high luminance levels. To investigate what is visible to 
 the human user at such luminances\, we measured contrast sensitivity from 
 0.02 cd/m2 to 7000 cd/m2 and for three colour directions (black-white or a
 chromatic\, red-green\, and yellow-violet). The stimuli were 2-dimensional
  wavelets of various spatial frequencies (0.125 to 6 cpd)\, shown on an HD
 R display. We found that achromatic contrast sensitivity has an inverted U
 -shape as a function of background luminance\, with peak sensitivity at 20
 0 cd/m2\; this means that the human visual system is less sensitive to ach
 romatic banding artifacts when viewing a bright scene\, requiring less det
 ailed representation of luminance. Red-green and yellow-violet contrast se
 nsitivities were monotonic functions of background luminance\, saturating 
 at 200 cd/m2 with no significant change up to 7\,000 cd/m2\; thus\, the hu
 man visual system remains equally sensitive to colour banding artifacts in
  when viewing a bright scene\, meaning that colour fidelity requirements a
 re constant at higher luminances. Based on these measurements\, we develop
 ed a model that predicts contrast sensitivity for the average observer.
LOCATION:SS03 Meeting Room\, Computer Laboratory
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