Overview
ISO/IEC TR 23002-9:2024 is an important technical report from ISO and IEC that addresses film grain synthesis technology for video applications. As part of the MPEG video technologies series, this document provides guidance for preserving or recreating the distinct appearance of film grain in digital video content. Film grain-the random, grainy effect seen in traditional celluloid film-is often desired in both cinematic productions and digital video for artistic effect or to mask compression artefacts. This report outlines methodologies for analyzing, modeling, synthesizing, and blending film grain within various MPEG video coding standards, supporting improved subjective quality and more efficient video compression.
Key Topics
ISO/IEC TR 23002-9:2024 covers several essential areas within the topic of film grain synthesis for video:
- Technical Characteristics of Film Grain
Discusses how film grain originates from analogue film processes and the role it plays in achieving the "cinematic look" in digital and physical media.
- Film Grain Modeling
Explains approaches for analyzing and parametrizing film grain, considering variations in brightness and color layers within film, and describes impacts on visual appearance.
- Film Grain Synthesis
Reviews end-to-end processes and models-such as frequency filtering and autoregressive approaches-used to recreate film grain on the decoder side after compression.
- Applications and Use Cases
Details how film grain synthesis is applied for both artistic purposes (restoring the filmic look) and practical outcomes (masking compression artefacts in streamed or broadcast video).
- Film Grain Metadata
Covers standard methods for representing and signaling film grain characteristics within MPEG bitstreams through metadata, facilitating interoperability.
- Workflow and Integration
Outlines encoder-side denoising and grain analysis, parameter exchange, and decoder-side grain synthesis and blending.
Applications
Film grain synthesis technology, as detailed in ISO/IEC TR 23002-9:2024, provides significant value across multiple industries and scenarios:
- Video Encoding and Compression
By temporarily removing film grain before compression, higher coding efficiency can be achieved without sacrificing visual fidelity. The grain can then be reintroduced during playback, reducing bandwidth while preserving artistic intent.
- Broadcast and Streaming Services
Essential for adaptive streaming and television broadcast, where bitrates must be managed carefully yet cinematic quality is expected.
- Film Restoration and Post-Production
Enables the preservation or recreation of film grain in restored cinema classics or in digitally shot films to unify the visual style or create an organic, immersive look.
- Visual Quality Enhancement
Adds synthetic film grain in post-processing to mask compression defects (such as banding or blocking) and to enhance perceived depth and texture in images.
- Hybrid Content Pipelines
Useful where footage from different cameras (analog, digital, varying sensors) is combined, ensuring a consistent grain structure throughout the project.
Related Standards
ISO/IEC TR 23002-9:2024 references and complements several other key standards in video coding and processing:
- Rec. ITU-T H.264 / ISO/IEC 14496-10
Advanced video coding (AVC)
- Rec. ITU-T H.265 / ISO/IEC 23008-2
High efficiency video coding (HEVC)
- Rec. ITU-T H.266 / ISO/IEC 23090-3
Versatile video coding (VVC)
- Rec. ITU-T H.274 / ISO/IEC 23002-7
Versatile supplemental enhancement information for coded video bitstreams
These standards define the core MPEG video frameworks into which film grain synthesis and metadata can be integrated, allowing for broad industry compatibility and deployment.
Incorporating film grain synthesis technology as covered in ISO/IEC TR 23002-9:2024 enables content creators, broadcasters, and streaming platforms to balance compression efficiency with high-quality, cinematic visual output. By following this standard, organizations can ensure consistent, interoperable implementation of film grain modeling within the latest MPEG video applications.
Open preview (PDF)Information technology — MPEG video technologies — Part 9: Film grain synthesis technology for video applications
