# Change Request Summary: HDR Images Support for FS_AIF_MED

## Document Information
- **CR Number**: S4-260264
- **Specification**: 26.9xx (version xx.x.x)
- **Work Item**: FS_AIF_MED
- **Category**: B (addition of feature)
- **Release**: Rel-20
- **Source**: Apple Inc.

## Overview
This Change Request proposes the addition of High Dynamic Range (HDR) imaging support to the AI for Media feasibility study. The CR introduces a new scenario for HDR images with supporting references and framework for evaluation.

## Main Technical Contributions

### Section 2: References
The CR adds seven new normative/informative references to support HDR imaging:

1. **Platform-specific HDR implementations**:
   - Apple developer documentation on HDR image support [1]
   - Android Ultra HDR Image Format documentation [2]

2. **ISO/IEC standards**:
   - ISO/IEC 23008-12: Image File Format for high efficiency coding [3]
   - ISO 22028-5: Extended colour encodings for HDR/WCG still images [6]
   - ISO 21496-1: Gain map metadata for dynamic range conversion [7]

3. **3GPP and GSMA specifications**:
   - 3GPP TS 26.143: Messaging Media profiles [4]
   - GSMA RCC.71: RCS Universal Profile Service Definition [5]

### Section 5.x: New Scenario for HDR Images

#### 5.x.1 Overview
- Defines HDR imaging as capturing greater range of light and dark tones compared to standard photography
- Highlights improved contrast and color on compatible displays
- References existing ecosystem implementations on major device platforms
- Emphasizes capability for modern devices to capture and share realistic images

#### 5.x.2 Review of Previous Work
- Identifies existing standardization support in ISO/IEC 23008-12 [3]
- Lists relevant HDR imaging standards:
  - ISO 22028-5 for HDR stills with extended colour encodings
  - ISO 21496-1 for HDR gain maps
- Notes 3GPP SA4 support in messaging applications (TS 26.143)
- References GSMA RCS support for HDR feature

#### 5.x.3 Evaluation Criteria and Metrics
- **Status**: To be completed (Editor's Note)

#### 5.x.4 Evaluation Methodology
- **Status**: Framework established but content to be completed
- Two subsections defined:
  - 5.x.4.1: Objective performance evaluation (TBC)
  - 5.x.4.2: Subjective performance evaluation (TBC)

## Key Technical Points

1. **Standards Alignment**: The proposal builds upon existing ISO/IEC and 3GPP work, ensuring compatibility with established HDR imaging standards

2. **Ecosystem Support**: References both major mobile platforms (iOS and Android) demonstrating industry readiness

3. **Messaging Integration**: Leverages existing 3GPP TS 26.143 and GSMA RCS specifications for messaging applications

4. **Evaluation Framework**: Establishes placeholder structure for both objective and subjective evaluation methodologies (content pending)

## Status
This is an initial framework CR with several sections marked for future completion, particularly the evaluation criteria and methodology sections.