Display Controller Using Regional Brightness Analysis to Reduce Haloing
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Solution Overview
Problem
Existing light modulating image displays, such as LCDs and LCPs, face a trade-off between achieving high contrast and dynamic range while minimizing visible boundaries between illumination elements, often resulting in undesirable artefacts like haloing.
Innovation Solution
A controller system that determines multiple brightness indications for image areas and adjusts illumination elements based on these indications, combining central tendency and upper extreme brightness values to generate illumination control information, thereby reducing perceptible haloing and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If illumination elements are controlled to maximize illumination for high luminance areas, then contrast and dynamic range are enhanced, but visible boundaries and haloing artefacts appear between illumination elements
Solution Approach 1:
The patent applies local quality by determining separate brightness indications for different regions within the area illuminated by each illumination element. Specifically, it identifies a first brightness indication for a first region and a second brightness indication for a second region, then controls each illumination element based on the appropriate regional brightness indication. This allows different parts of the illuminated area to have different illumination characteristics, enhancing contrast in high luminance areas while minimizing haloing in low luminance areas.
2Object-affected harmful factors
If illumination elements are controlled to minimize illumination for low luminance areas, then haloing is reduced, but contrast and dynamic range are compromised
Solution Approach 1:
The patent resolves this contradiction by implementing local quality control through regional brightness analysis. It divides the illuminated area into multiple regions and determines separate brightness indications for each region. The controller then selectively applies different illumination control strategies to different regions, maintaining high contrast where needed while minimizing haloing where appropriate.
3Manufacturing precision
If multiple brightness indications are determined and combined, then image quality and fidelity are improved, but controller complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the image data into multiple subsets corresponding to different regions illuminated by each illumination element. It determines separate brightness indications for each subset (first brightness indication for first region, second brightness indication for second region), then combines these indications to generate the final illumination control information. This segmented approach improves image fidelity while keeping the controller complexity manageable through systematic processing.
Data Source
AI summary
Methods for controlling light sources in displays in response to image data determine both a central tendency for brightness and an upper extreme for brightness of an area of an image. Brightness of a light source is controlled based upon both the central tendency and the upper extreme. Controllers in displays such as televisions, computer monitors, digital cinema and the like may control light source in a manner that reduces or avoids perceptible haloing.