Colour Discrepancy problem in RAW conversions

1. Investigating Colour Discrepancy
problem in RAW Conversions and
Searching for Progressive Digital
Cinematography workflow for
Stop Motion Animation
ann leung
school of design, the hong kong polytechnic university

2. Student animation projects

3. Student Projects Outcome
• Didn’t import RAW files but converted to .tiff
16, .tiff, .tga or .jpeg
• Didn’t utilize the colour gamut & wrong colour
space
• Image artifacts: pixelation and posterized
effects

4. Corpse Bride, Tim Burton (2005)
• Canon EOS-1D Mark II
• 2K conform to film output through DI process
• Import RAWs into a proprietary software, then
output to Cineon log space (in order to bake
the Eastman EXR 100T 5248 film stock look)
*Cineon digital film system refers to the film scanning and
recording h/w designed by Kodak and they introduced Cineon
(.cin) file format in 1997
• Transforms to 2K DPX sequence
* DPX stands for Digital Picture Exchange, a file format
designed to preserve film negative data while obtained from
digital film scanner.

5. Preliminary Test
• Shoot photos with Canon EOS 1000D & Nikon
D70
• Imported the RAWs with:
– DCRAW (free RAW converter, C language program)
– Canon’s DPP and Nikon’s CaptureNX2
– Adobe PS CS4’s CamRAW
• Compared their Colour space profiles using
the CIELUV 1976 diagram

7. Image Acquisition

8. CIE(Commission international de
I’Eclariage) 1976 L*, u*, v* Diagram
Image courtesy of wikipedia.org

9. CIE LUV & Colour Space

10. Image Acquisition and ‘Bayer Filter’
Bayer Filter (an algorithm called ‘Colour Filter Array’)
Image courtesy of wikipedia.org

11. Camera’s Sensor unit & Processor
• Canon – DIGIC; DIGIC II; DIGIC III; DIGIC 4; DIGIC
5; DIGIC 5+
• Nikon – Expeed; Expeed 2; Expeed C2; Expeed 3
• Sony Alpha – BIONZ
• RED ONE – MYSTERIUM-X
Nikon D90’s Sensor Unit
Nikon D90’s Processor
Image courtesy of Nikon’s website

12. DSLR Camera Framework

13. Digital Cinematography
• Full digital workflow
• Process image data with Imaging Science approach
and output them back to film afterwards
• Being well accepted after the movie
Slumdog Millionaire (2008) which own the academy
award for Best Cinematography

14. Digital Intermediate (DI)
Image courtesy of
apple.com

15. Second Test Method
Table top setup in the Studio shooting. We
only display results from following cameras:-
•Canon 5D mark II
•Nikon D700

16. The 4 lighting conditions

17. • Fig. 11 – Normal lighting
• Fig. 12 – Red lighting
• Fig. 13 – Green lighting
• Fig. 14 – Blue lighting

18. • Fig. 15 – Red lighting
• Fig. 16 – Green lighting
• Fig. 17 – Blue lighting

19. Our experiments outcome
• Nikon D700 performed better under red
lighting conditions
• Canon 5D mark II favored blue colour tone
environments
• Different brands of camera exhibited different
behaviors on colour visualization
• Animators are advised to carefully select their
camera beforehand as well as the conversion
method

20. Other intermediate conversion formats?
• R3D RAW (RED camera)
• ARRI RAW
• DPX
• Adobe’s DNG (Digital Negative format)
• OpenEXR/HDR (www.openexr.com)
• CineForm RAW (www.cineform.com)

21. • Adobe’s DNG CIE
Performance

22. HD-DI Workflow
High Definition and High Dynamic-Digital
Intermediate Workflow