Color Workflow in VFX

Transcription

1 1 Display-referred Imagery GOAL Imagery immediately watchable on display in sufficient quality CHARACTER High Contrast - Low Dynamic Range EXAMPLES Standard Photography Television/Video Internet Mobile Devices

2 1 Display-referred Imagery ADVANTAGES Easy handling throughout the pipeline Non-linear coding (2-3 bits less needed) DISADVANTAGES Relation to the light of the scene lost No dynamic range between reference white and glossy highlights Imagery destructively changed by Transfer function (Gamma) and company related curves

3 2 Scene-referred Imagery GOAL Linear relationship to the original light of the scene CHARACTER Low Contrast - High Dynamic Range EXAMPLES Film/cinema VFX for Film

4 2 Scene-referred Imagery ADVANTAGES Sufficient dynamic range between Reference White and Glossy Highlights Easy Black Coding Imagery of different sources combinable Physical Plausible Rendering possible All Filter and Compositing operations benefit from dynamic ranges /Patrick Ingwer: Game of Colors - Moderne Bewegtbildproduktion, Springer-Vieweg, Berlin 2016,

5 3 The Standard Workspace GOAL Maintain the linear relationship to the light of the scene Physical Based Rendering possible /Patrick Ingwer: Game of Colors - Moderne Bewegtbildproduktion, Springer-Vieweg, Berlin 2016,

6 3 The Workspace PROBLEM I The values are just numbers no relation to a color space until delivery

7 3 The Workspace SOLUTION Using the AMPAS ACEScg *) Color space Wide gamut colorspace All software packages are working in this color space AMPAS = Academy of Motion Picture Arts and Sciences ACES = Academy Color Encoding System

8 3 The Workspace PROBLEM 1I The material cannot viewed properly because of the dynamic range Material looked washed out

9 3 The Workspace SOLUTION - View Transform Consists of Reference Render Transform (RRT) S-shape based curve mimicking the behavior of film negative High-Dynamic material is rolled-in the dynamic range of the monitor Output Device Transform Transferfunction (OECF - Gamma ) Colorspace conversion

10 3 The Workspace SOLUTION - Using LUTs RRT and ODT are packed into a Lookup table (LUT) Provided and applied throughout the pipeline All Software Packages All VFX-Vendors Used as starting point for Digital Intermediate (delivery)

11 4 The Input Device Transform GOAL Creating a linear relationship to the light of the scene ADVANTAGES Recordings of different sources combinable /Patrick Ingwer: Game of Colors - Moderne Bewegtbildproduktion, Springer-Vieweg, Berlin 2016,

12 4 The Input Device Transform PROBLEM Camera vendors are applying different color conversions to achieve a look the company is associated with Spectral Camera (lined out) RED Color 2 (solid)

13 4 The Input Device Transform SOLUTION 1 Using the ACES IDTs

14 4 The Input Device Transform SOLUTION II Creating your own camera characterization After the camera software had been applied!!! /Patrick Ingwer: Game of Colors - Moderne Bewegtbildproduktion, Springer-Vieweg, Berlin 2016,

15 5 The Workspace using ACES WORKFLOW The recorded material should not be changed - Do no harm to the plate The files are provided through the pipeline linearly Open EXR files with half floating point precision (- --> + ) are used Academy Color Encoding System (ACES) /Patrick Ingwer: Game of Colors - Moderne Bewegtbildproduktion, Springer-Vieweg, Berlin 2016,

16 THANK YOU!