Hybrid Analog-Digital Gamut Mapping for Luminance Preservation
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Solution Overview
Problem
Existing techniques for switching from a larger color gamut to a smaller color gamut result in luminance loss and color accuracy errors, with digital mapping causing significant luminance loss and analog techniques leading to color accuracy issues.
Innovation Solution
A hybrid analog/digital technique is employed, where the gain value of primary colors is reduced in the analog domain to preserve luminance, and subsequent digital post-processing is used to correct color accuracy errors, thereby providing a smaller color gamut with both preserved luminance and threshold color accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digital mapping is used to convert from larger color gamut to smaller color gamut, then color accuracy is improved, but luminance loss increases significantly
Solution Approach 1:
The patent divides the color gamut conversion process into two separate stages: first performing analog gain adjustment to preserve luminance, then performing digital mapping to correct color accuracy. This segmentation allows each stage to optimize for its specific function without compromising the other, resolving the contradiction between luminance preservation and color accuracy.
Solution Approach 2:
The patent applies preliminary analog gain adjustment before digital mapping. By first adjusting the gain values of primary colors in the analog domain to preserve luminance, the subsequent digital mapping operation can focus solely on color accuracy correction without causing additional luminance loss.
2Loss of energy
If analog gain reduction is applied to primary colors to preserve luminance, then luminance is maintained, but color accuracy deteriorates
Solution Approach 1:
The patent separates the luminance preservation function (analog gain adjustment) from the color accuracy correction function (digital mapping). This segmentation allows the analog stage to maintain luminance while the subsequent digital stage corrects color accuracy, resolving the contradiction between these two requirements.
Solution Approach 2:
The patent introduces digital mapping as an intermediary correction step after analog gain adjustment. This intermediary process compensates for the color accuracy degradation caused by analog gain reduction, allowing the system to achieve both luminance preservation and color accuracy.
3Measurement precision
If direct digital mapping is performed from native color gamut to reduced color gamut, then color accuracy threshold is met, but luminance loss exceeds threshold
Solution Approach 1:
The patent performs preliminary analog gain adjustment with luminance preservation before executing digital mapping. This preliminary action ensures that when digital mapping is applied, the luminance loss is already minimized, allowing the final output to meet both color accuracy threshold and luminance loss threshold requirements.
Solution Approach 2:
The patent segments the conversion process into analog luminance-preserving gain adjustment followed by digital color-accurate mapping. This segmentation enables the system to achieve both color accuracy and luminance preservation, directly resolving the contradiction present in direct digital mapping approaches.
Data Source
AI summary
This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for reducing gamut mapping luminance loss. A gain value of at least one primary color may be reduced in a native color gamut based on an analog technique (e.g., using a DDIC in a display panel) to provide a reduced color gamut that is smaller than the native color gamut. The reduced color gamut may have a same luminance as the native color gamut. One or more colors included in the native color gamut may be mapped via a digital technique (e.g., using a DPU or other processor) to the reduced color gamut. The mapping may be configured to provide a threshold level of color accuracy in the reduced color gamut.