REPORT ITU-R BT.2408-6 – Guidance for operational practices in HDR television production Foreword Policy on Intellectual Property Right (IPR) Summary TABLE OF CONTENTS 1 Introduction 2 Reference levels and signal format 2.1 HDR Reference White 2.2 Signal levels for line-up in production 2.3 Bit depth 2.4 Signal range 2.5 Colour representation 3 Monitoring 3.1 Display of PQ signals 3.1.1 Mapping to displays with limited luminance range 3.2 Display of HLG signals 3.2.1 Display of HLG signals on SDR screens 4 Image brightness 4.1 Comfortable brightness of static images 4.2 Tolerance to programme brightness shifts 5 Integrating standard dynamic range and high dynamic range production 5.1 Inclusion of standard dynamic range content in high dynamic range 5.1.1 Display referred mapping 5.1.2 Display referred mapping of SDR into PQ 5.1.3 Display referred mapping of SDR into HLG 5.1.3.1 Mapping without OOTF adjustment 5.1.3.2 Mapping with OOTF adjustment 5.1.3.3 Scaling 5.1.3.4 Simplification of the HLG mapping process 5.1.4 Scene referred mapping 5.1.4.1 Scene referred mapping of SDR into HLG 5.1.5 Comparing scene-light and display-light direct-mapping 5.2 HDR to SDR down-mapping 5.3 Handling negative values in format conversion 5.4 Adjustments to BT.709 cameras 5.5 Use of 8-bit content 5.6 Mapping of SDR graphics 6 Conversion between PQ and HLG 6.1 Transcoding concepts 6.2 Conversion concepts using a reference condition at 1 000 cd/m2 6.3 Cameras using a common OOTF at a reference peak luminance of 1 000 cd/m2 6.4 Handling PQ signals with greater than 1 000 cd/m2 peak luminance 6.5 Possible colour differences when converting from PQ to HLG 7 Transitioning from SDR BT.709 to HDR BT.2100 production 7.1 HDR focused production 7.2 SDR focused production 7.2.1 PQ production with SDR shading 7.2.2 HLG production with SDR shading UHD and HD resolution HDR camera outputs HDR slow-motion HDR to SDR down-mapping 7.2.2.1 HDR and SDR monitors in close proximity 7.3 SDR-HDR and HDR-SDR format conversion 7.3.1 PQ conversion 7.3.2 HLG conversion 7.3.3 The displayed “look” of content following format conversion 7.3.4 Signal range considerations for HDR to SDR conversion 7.4 SDR-HDR-SDR “Round-Tripping” 7.5 Hardware colour matrix compensation 7.6 Signal line-up 7.7 Camera painting 8 Conversion practices for camera and display RGB colorimetry Annex 1 Study to evaluate levels for PQ content Annex 2 Analysis of reference levels A2.1 Introduction A2.2 Analysis of reference levels A2.3 Diffuse white elements in live HLG encoded broadcast content A2.4 Diffuse white in an HDR dataset of 1 000 cd/m2 PQ encoded images A2.5 Discussion A2.6 Conclusions Annex 3 Two studies of skin tones, using a reflectance database and using real subjects A3.1 Study 1: using a skin tone database and an ideal model of a camera A3.2 Study 2: using human subjects and a RAW recording camera A3.3 Conclusions Annex 4 Study of facial skin tones in broadcast content A4.1 Facial skin tones in SDR news and information programmes in studio A4.2 Comparison of facial skin tones in HLG HDR and SDR content in a music programme A4.3 Conclusion Annex 5 Displaying PQ – calculating the EETF Annex 6 Comparison of the native looks of HDR and SDR production A6.1 Differences in chromaticity and saturation A6.2 Quantifying the total colour differences A6.3 Comparison with the reference colour pattern data Annex 7 Calculating the normalized primary matrix A7.1 Conversion of normalized linear colour signals to Recommendation ITU-R BT.2100 A7.2 Conversion of BT.2100 to arbitrary linear colour signals for display systems Annex 8 4K/8K UHD HDR and HD SDR simul-production and simulcast practice in China A8.1 Background A8.2 Basic workflows and principles A8.3 Introduction of related work and research A8.4 Mapping for conversion between HDR and SDR A8.5 Parameter settings A8.6 Converter performance consistency (LUTs usage) A8.7 Signal range A8.8 Consistency of international exchange A8.9 Conclusions Annex 9 HDR and SDR monitors in close proximity A9.1 Approach used by BBC A9.2 Approach used by NBCUniversal Annex 10 NBCUniversal single-master HDR-SDR workflow Annex 11 Conversion between 203 cd/m2 and 100 cd/m2 (BT.2035) SDR signal formats Glossary