Block-Based Gradient Descent for Local Backlight Dimming and Flicker Reduction

Nino Burini, Claire Mantel, Ehsan Nadernejad, Jari Korhonen, Søren Forchhammer, Jesper Melgaard Pedersen

    Research output: Contribution to journalJournal articleResearchpeer-review


    Local backlight dimming technology is a two-fold improvement for LED backlit LCD screens that allows to reduce power consumption and increase visual quality. This paper presents a fast version of an iterative backlight dimming algorithm based on gradient descent search. The speed is increased by exploiting the local uniformity of backlight to reduce the complexity for determining the optimal backlight of a given image. The algorithm is adapted to video sequences by using the backlight of the previous frame as a starting point to calculate the backlight for the current frame. Fast variations of backlight dimming over time can produce a visually annoying flicker artifact. To avoid this artifact, a control mechanism is also proposed.
    Original languageEnglish
    JournalJournal of Display Technology
    Issue number1
    Pages (from-to)71-79
    Publication statusPublished - 2014


    • Backlight dimming
    • Video
    • Flicker
    • Image quality
    • LED backlight
    • Light leakage
    • Liquid crystal display (LCD)
    • Optimization
    • Power saving


    Dive into the research topics of 'Block-Based Gradient Descent for Local Backlight Dimming and Flicker Reduction'. Together they form a unique fingerprint.

    Cite this