The ARRI Companion to Digital Intermediate

Harald Brendel

Head of Application Engineering Digital Intermediate
Arnold & Richter Cine Technik GmbH & Co Betriebs KG

Second Edition: September 2005

Table of Contents

1. Introduction
1.1. The Digital Intermediate Process
Digital Intermediate Overview
Preserving The Quality of The Image
1.2. A Quick Overview
2. Motion Picture Film
2.1. Camera Negative Film
General Characteristics
Transmittance and Density
Characteristic Curve
2.2. Intermediate Film
General Characteristics
Characteristic Curve
2.3. Print Film
General Characteristics
Characteristic Curve
2.4. Summary
3. Scanning
3.1. General Concepts
Spatial Resolution
Dynamic Range
Cineon/DPX Format
Image Formation
Linear Image Formats
3.3. Summary
4. Recording
4.1. General Concepts
CRT Recorder
Laser Recorder
4.3. Summary
5. Digital Display Devices
5.1. CRT Monitors
General Characteristics
Characteristic Curve
5.2. DLP Projectors
General Characteristics
Characteristic Curve
5.3. Displaying Images
Grayscale Matching
Transfer Curve in Broadcast System
5.4. Summary
6. Color Processing
6.1. Color Rendering of Photographed Images
Color Gamut
CIE Color Spaces
Gamut Comparison
Color Matching
6.2. Color Correction
Color Encoding
Primary Color Correction
A Color Correction Example
Problems with Color Film
6.3. Summary
7. Final Thoughts
A. File Formats
A.1. Cineon File Format
A.2. DPX File Format
Are 10 Bits Enough?
A.3. Grayscale Encoding in Digital Files
A.4. Color Encoding in Digital Files
B. Color Characteristics of Scanners and Recorders
B.1. Spectral Response
Status M
Printing Density
B.2. Film Scanner
B.3. Film Recorder

List of Figures

1.1. Scene rendered for monitor display.
2.1. Cross section of color negative film before and after processing.
2.2. Characteristic curve of a color negative.
2.3. Grain structure of intermediate film (left) and of camera negative film (right).
2.4. Density histogram of an unexposed film
2.5. The IP/IN process
2.6. Cross section of color print film before and after processing.
2.7. Characteristic curve of print film.
2.8. IN to positive printing curve.
2.9. Motion picture print through curve.
3.1. Comparison between 2K and 4K resolution.
3.2. Aliasing in digital image.
3.3. Grayscale gradient in different bit depths.
3.4. Color processing in different bit depths.
3.5. Encoding of negative densities in the Cineon/DPX file format.
3.6. Scene in log density encoding.
3.7. Specific tonal values in the sample image.
3.8. The histogram of the log encoded sample image.
3.9. Histogram showing gaps.
3.10. Relation between film transmittance and sensor signal.
3.11. Relation between sensor signal and log encoding.
3.12. Scene in linear luminance encoding (full range).
3.13. Linear encoding of scene luminance in 16 bit code values.
3.14. Encoding of log scene luminance in 10 bit code values.
3.15. Relation between scene luminance and scanner sensor signal.
3.16. Low and high image used in the ARRISCAN
4.1. Aim for recorder calibration.
5.1. Characteristic curve of CRT monitor as linear plot.
5.2. Characteristic curve of CRT monitor as logarithmic plot.
5.3. Characteristic curve of DLP projector as logarithmic plot.
5.4. Transfer curve for print film contrast simulation on CRT monitor.
5.5. Linear luminance encoding clipped above reference white.
5.6. Scene in linear luminance encoding clipped above reference white.
5.7. ITU-R BT.709 transfer curve.
5.8. Broadcast system transfer curve.
6.1. Gamut comparison of DLP, CRT, and print film in a chromaticity diagram.
6.2. Gamut comparison of DLP, CRT, and print film in CIELAB space.
6.3. Rendering of print film colors on a CRT monitor.
6.4. Rendering of print film colors on a DLP projector.
6.5. Scene in print film contrast rendering.
6.6. Grayscale versus color matching.
6.7. LUT
6.8. 3D LUT
6.9. DI work flow based on log encoded image data.
6.10. DI work flow based on video encoded image data.
6.11. Scene graded as “day for night” in log encoding.
6.12. Scene graded as “day for night“ in video encoding.
6.13. White points of video and film.
A.1. High density range in camera negative.
A.2. Print preview of high density range in camera negative.
B.1. Status M and Printing Density.
B.2. ARRISCAN color calibration.

List of Tables

2.1. Exposure scales.
2.2. Scene luminance, log exposure and negative densities
3.1. Relation of negative densities and 10 bit log code values.