Inter-layer Predictor for Enhanced Dynamic Range Video
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current video compression techniques face challenges in efficiently encoding and decoding signals with enhanced dynamic range (EDR) while maintaining compatibility with legacy systems and supporting new high-definition (HD) and ultra-high-definition (UHD) display technologies, particularly in inter-layer prediction methods.
Innovation Solution
The development of an inter-layer prediction method that adjusts pixel data prediction based on statistical values, using a highlights clipping constraint to set a fixed output for SDR pixel values above a highlights threshold and setting residual values to zero for SDR pixel values below a dark-regions threshold, employing an 8-segment MSE predictor and calculating dark-regions thresholds from cumulative variance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional SDR to EDR prediction is used without adjustment, then the coding process is simple, but prediction errors are large in highlights regions
Solution Approach 1:
The patent applies parameter changes by adjusting the inter-layer predictor output based on the relationship between SDR and EDR pixel values. When an SDR pixel value is greater than an EDR pixel value, the predictor output is adjusted to the EDR pixel value, thereby reducing prediction errors in highlights regions while maintaining overall coding efficiency
Solution Approach 2:
The patent introduces an intermediary mechanism by using the EDR pixel value as a reference to adjust the SDR to EDR prediction. This intermediary approach allows the system to correct prediction errors without requiring complex reprocessing, simply by comparing and adjusting based on the relationship between SDR and EDR values
2Manufacturing precision
If a fixed prediction method is used for all pixel values, then the processing is efficient, but the quality in both highlights and dark regions deteriorates
Solution Approach 1:
The patent applies local quality by treating different pixel value ranges differently. It identifies highlights regions (where SDR > EDR) and dark regions (where both values are low) and applies specific correction rules to each, thereby improving local reconstruction quality without requiring complete reprocessing of all pixels
3Manufacturing precision
If residual values are not constrained in dark regions, then the coding is straightforward, but the reconstruction quality in dark regions deteriorates
Solution Approach 1:
The patent applies discarding and recovering by setting residual values to zero in dark regions where the SDR pixel value is less than a threshold. This discards potentially noisy residual information in dark regions and recovers quality by relying on the prediction alone, avoiding the complexity of processing low-signal residual data
Data Source
Figure 1
Figure 2A~2B
Figure 2C~2D
AI summary
Pixel data of a video sequence with enhanced dynamic range (EDR) are predicted based on pixel data of a corresponding video sequence with standard dynamic range (SDR) and an inter-layer predictor. Under a highlights clipping constrain, conventional SDR to EDR prediction is adjusted as follows: a) given a highlights threshold, the SDR to EDR predictor is adjusted to output a fixed output value for all input SDR pixel values larger than the highlights threshold, and b) given a dark-regions threshold, the residual values between the input EDR signal and its predicted value are set to zero for all input SDR pixel values lower than the dark-regions threshold. Example processes to determine the highlights and dark-regions thresholds and whether highlights clipping is occurring are provided.