Adaptive Streaming False Contouring Alleviation

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Solution Overview

Problem

Existing video codecs struggle to effectively alleviate banding artifacts in images with lower bit depths, such as 8-bit video signals, especially when displayed on devices with limited dynamic range capabilities.

Innovation Solution

The implementation of an adaptive streaming framework that injects luminance-dependent noise into HDR video signals to generate multiple spatial resolution and bitrate ladder video signals, which can be decoded and displayed on end-user devices with moderate decoding and display capabilities, effectively reducing false contouring and banding artifacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If video signals are compressed to lower bit depths for efficient transmission and storage, then transmission efficiency and storage capacity are improved, but banding artifacts and false contouring increase

Engineering Contradiction:

Improvetransmission efficiencyVSAvoidbanding artifacts

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful banding artifacts into beneficial visual content by injecting synthesized film grain noise that matches the characteristics of original film grain. This noise masks the false contours caused by quantization, transforming the visual defect into an aesthetically pleasing artifact that resembles authentic film texture.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the parameter of noise injection by modulating the noise strength according to luminance slopes of forward reshaping functions. The noise injection amount is dynamically adjusted based on local luminance variations, applying stronger noise in regions prone to banding and weaker noise in smooth regions, thereby optimally masking artifacts while preserving image quality.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If noise is injected into video signals to mask banding artifacts, then visual quality is improved, but the complexity of the encoding process increases

Engineering Contradiction:

Improvevisual qualityVSAvoidencoding process complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent modifies the encoding process by introducing parameter-based noise injection where the noise strength is controlled by luminance slope calculations from forward reshaping functions. This parameterized approach allows systematic control of noise characteristics without requiring complex machine learning models or iterative optimization processes.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary processing stage between tone mapping and encoding where noise is injected. This intermediary step uses forward reshaping function derivatives as a mediator to determine appropriate noise levels, creating a bridge between the tone mapping process and the final encoding without requiring direct complex interaction between these stages.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple video signals with different spatial resolutions and bitrates are generated, then adaptability to different display devices is improved, but processing time and computational resources increase

Engineering Contradiction:

Improveadaptability to display devicesVSAvoidprocessing time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent performs preliminary noise injection and banding alleviation during the initial encoding stage before generating multiple resolution versions. By addressing the banding issue once at the source, the processed video signals can be efficiently scaled to different resolutions without requiring repeated complex noise injection operations for each resolution level.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a universal noise injection process that works across multiple video signals with different spatial resolutions and bitrates. The luminance-dependent noise injection method is resolution-independent and can be applied uniformly to generate adaptive streaming ladders, making the process multi-functional rather than requiring separate processing for each resolution.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12301848B2Adaptive streaming with false contouring alleviation

Publication Date: 2025.05.13 DOLBY LABORATORIES LICENSING CORP

AI summary

A forward reshaping mapping is generated to map a source image to a corresponding forward reshaped image of a lower dynamic range. The source image is spatially downsampled to generate a resized image into which noise is injected to generate a noise injected image. The forward reshaping mapping is applied to map the noise injected image to generate a noise embedded image of the lower dynamic range. A video signal is encoded with the noise embedded image and delivered to a recipient device for the recipient device to render a display image generated from the noise embedded image.