Adaptive PQ-EOTF HDR Image Processing for Bright Environment Visibility
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Solution Overview
Problem
Display devices experience luminance saturation and reduced visibility when displaying HDR images in bright environments due to the use of PQ-EOTF derived in dark conditions, leading to gray-level banding in high luminance regions.
Innovation Solution
An adaptive method and module that adjusts the PQ-EOTF based on illuminance levels, using an illuminance sensor to apply weights to luminance information, and employs first and second mapping functions to increase luminance in high-luminance regions while maintaining power consumption by clipping luminance when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If PQ-EOTF is used for HDR image processing in display devices, then the device can display HDR images with high dynamic range, but luminance saturation and gray-level banding occur in bright rooms, deteriorating visibility
Solution Approach 1:
The patent applies dynamics by making the EOTF curve adjustable based on environmental illuminance conditions. The display device dynamically switches between a first EOTF curve (for dark rooms) and a second EOTF curve (for bright rooms) according to sensor input, allowing the system to adapt its luminance characteristics to match viewing conditions and avoid luminance saturation in bright environments
Solution Approach 2:
The patent changes the parameters of the EOTF curve based on illuminance levels. By adjusting the EOTF curve parameters according to environmental light conditions, the system optimizes the mapping between digital luminance values and actual display luminance, preventing gray-level banding and improving visibility in different lighting scenarios
2Reliability
If luminance is increased in high-luminance regions to improve visibility, then gray-level distinguishability improves, but power consumption increases
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different luminance regions within the image. The second EOTF curve is specifically designed to enhance gray-level distinguishability in high-luminance regions while maintaining appropriate luminance levels in other regions, providing localized optimization for visibility without unnecessarily increasing power consumption across the entire display
Data Source
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AI summary
Disclosed herein are a method and module for processing a high dynamic range (HDR) image, which are capable of improving visibility according to illuminance, and a display device using the same. In one embodiment, illuminance information sensed through an illuminance sensor is received, a perceptual quantizer electro-optical transfer function (PQ-EOTF) is adjusted, and gray level information of a first HDR image is converted into luminance information of a second HDR image using the adjusted PQ-EOTF. The luminance information of the second HDR image is analyzed to calculate a high-luminance rate of occupancy of pixels having target peak luminance or more of a display device in the second HDR image. The second HDR image is luminance-mapped to a third HDR image suitable for the display device using a mapping function changed according to the high-luminance rate.