Contrast Sensitivity Experiment to Determine the Bit Depth for Digital Cinema
Matthew D. Cowan, Glenn L. Kennel, Thomas Maier, Brad Walker · SMPTE Motion Imaging Journal · 2004
The SMPTE Color ad hoc group was formed in 2001 (under DC28.2) to investigate the colorimetric requirements for the Digital Cinema Distribution Master (DCDM). A draft specification on color image encoding was published in September 2002 that recommended the use of XYZ color space, a gamma 1/2.6 transfer function, and 12 bits per color. With the support of Digital Cinema Initiatives (DCI), a test was designed to verify these color image encoding parameters. This paper reports the results of the contrast sensitivity experiment, which showed that many of our observers could see a modulation corresponding to a one code value change with 10-bit encoding, but few observers would see a one-code value change with 12-bit encoding. This result matches the results of published contrast sensitivity experiments.