TY - GEN
T1 - Subjective comparison of brightness preservation methods for local backlight dimming displays
AU - Korhonen, Jari
AU - Mantel, Claire
AU - Forchhammer, Søren
N1 - Copyright 2015 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic electronic or print reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
PY - 2015
Y1 - 2015
N2 - Local backlight dimming is a popular technology in high quality Liquid Crystal Displays (LCDs). In those displays, the backlight is composed of contributions from several individually adjustable backlight segments, set at different backlight luminance levels in different parts of the screen, according to the luma of the target image displayed on LCD. Typically, transmittance of the liquid crystal cells (pixels) located in the regions with dimmed backlight is increased in order to preserve their relative brightness with respect to the pixels located in the regions with bright backlight. There are different methods for brightness preservation for local backlight dimming displays, producing images with different visual characteristics. In this study, we have implemented, analyzed and evaluated several different approaches for brightness preservation, and conducted a subjective study based on rank ordering to compare the relevant methods on a real-life LCD with a local backlight dimming capability. In general, our results show that locally adapted brightness preservation methods produce more preferred visual outcome than global methods, but dependency on the content is also observed. Based on the results, guidelines for selecting the perceptually preferred brightness preservation method for local backlight dimming displays are outlined.
AB - Local backlight dimming is a popular technology in high quality Liquid Crystal Displays (LCDs). In those displays, the backlight is composed of contributions from several individually adjustable backlight segments, set at different backlight luminance levels in different parts of the screen, according to the luma of the target image displayed on LCD. Typically, transmittance of the liquid crystal cells (pixels) located in the regions with dimmed backlight is increased in order to preserve their relative brightness with respect to the pixels located in the regions with bright backlight. There are different methods for brightness preservation for local backlight dimming displays, producing images with different visual characteristics. In this study, we have implemented, analyzed and evaluated several different approaches for brightness preservation, and conducted a subjective study based on rank ordering to compare the relevant methods on a real-life LCD with a local backlight dimming capability. In general, our results show that locally adapted brightness preservation methods produce more preferred visual outcome than global methods, but dependency on the content is also observed. Based on the results, guidelines for selecting the perceptually preferred brightness preservation method for local backlight dimming displays are outlined.
KW - Displays
KW - Local backlight dimming
KW - Image processing
KW - Image quality
KW - Visual effects
U2 - 10.1117/12.2079241
DO - 10.1117/12.2079241
M3 - Article in proceedings
VL - 9395
T3 - Proceedings of SPIE, the International Society for Optical Engineering
SP - 939504
BT - Proceedings of the SPIE
PB - SPIE - International Society for Optical Engineering
T2 - Color Imaging XX: Displaying, Processing, Hardcopy, and Applications
Y2 - 8 February 2015 through 12 February 2015
ER -