Projector Color Conversion for Affordable HLG-HDR Projection
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Solution Overview
Problem
Current projectors do not support high dynamic range imaging (HLG-HDR) class input signals, leading to improper color shifts in projected images, and affordable projectors lack the capability to display HLG-HDR images effectively.
Innovation Solution
A projector system that includes a processor to decode metadata, convert color spaces, and perform gamma corrections based on electro-optical transfer functions (EOTFs) to adapt image signals to narrower color gamuts supported by the projector, enabling proper display of HLG-HDR and non-HLG-HDR images without increasing cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the projector uses a standard processor without HLG-HDR support, then the device complexity and cost are kept low, but the color accuracy and image quality deteriorate when processing HLG-HDR signals
Solution Approach 1:
The patent introduces an intermediary color space conversion process that acts as a bridge between the HLG-HDR input signal and the projector's standard processing pipeline. The receiver converts HLG-HDR signals to a compatible color space format before processing, allowing the standard processor to handle HDR content without requiring expensive HLG-HDR native support. This intermediary conversion layer resolves the contradiction by enabling color accuracy improvement while maintaining device simplicity.
Solution Approach 2:
The patent dynamically changes processing parameters based on the input signal type. When HLG-HDR content is detected, the system activates specific color space conversion parameters and processing modes. This allows the projector to optimize color accuracy for HDR signals while maintaining cost-effective standard hardware, resolving the contradiction between processor complexity and color accuracy.
2Adaptability or versatility
If the projector converts color space from wider gamut to narrower gamut, then the compatibility with standard processors is improved, but the color gamut coverage and image quality may be reduced
Solution Approach 1:
The patent implements dynamic color space conversion that adapts to the specific input signal characteristics. Rather than a fixed conversion, the system dynamically adjusts conversion parameters based on the detected signal type (HLG-HDR, HDR, or SDR). This dynamic approach maintains maximum color gamut coverage while ensuring compatibility with standard processors, resolving the contradiction between adaptability and color precision.
Solution Approach 2:
The patent applies different conversion strategies to different portions of the color space. Critical color regions are preserved with higher fidelity while less critical regions undergo standard conversion. This local quality approach ensures that important color information is maintained even when converting from wider to narrower gamuts, balancing compatibility with color gamut coverage.
Data Source
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AI summary
A projector and a method for projecting an image light beam according to an image signal are provided. The method includes: receiving the image signal; decoding the image signal to obtain a metadata of the image signal; determining whether the image signal is a HLG-HDR signal according to the metadata; converting a color space of the image signal from a wider color gamut to a narrower color gamut in response to the image signal is the HLG-HDR signal so as to generate a converted image signal; performing a gamma correction on the converted image signal according to the metadata to generate a corrected image signal; transferring the corrected image signal into an optical signal; providing a light beam; respectively modulating the light beam and a illumination beam according to the optical signal to form an image light beam; and projecting the image light beam.