Webinar – Colour Pipeline for HD Display

Presenter: Charles Poynton
Duration: Three, two-hour sessions
Date/time: [[not scheduled at present]]


Question: How was it possible, several years, ago that many tens of millions of consumer DVD players shipped with a fairly serious colour signal processing error, the “chroma upsampling error” (CUE)? Answer: Video displays – studio displays, field monitors, consumer televisions, and projectors – are supposed to have a specific colour signal processing path, but not all manufacturers have sufficient detailed technical knowledge of the pipeline to get it right!

The CUE example is dated; however, the fundamental problem persists: Many contemporary HD devices have errors in their signal processing. For example, some so-called studio reference displays have incorrect chromaticity; many LCD displays have flawed treatment of the LCD panel “gamma” characteristics; many home theatre displays have “colour management system” (CMS) controls located at the wrong point in the signal path; and consumer television sets commonly have signal path parameters that are tuned to meet the needs of showroom environments, not consumers’ living rooms. Even the placement in the signal path of gain and offset controls, and their misleading names CONTRAST and BRIGHTNESS, presents problems. It's up to video calibrators to repair these problems; that task can be greatly simplified with an understanding of the correct processing path. Better still, if manufacturers implement the signal path correctly, the problems can be avoided completely.

In this webinar, Charles Poynton will review the HD colour signal path. He will discuss chroma interpolation, luma/chroma matrixing, and treatment of gamma. He will describe matrixing of primary signals to map between different chromaticity standards. Charles will explain the details of the BT.709 standard that define some aspects of the HD signal, and will introduce the BT.1886 standard that finally standardizes the missing gamma parameter of HD. Appearance depends to some extent upon viewing conditions: Charles will describe the visual effects related to this issue, and will explain how they are compensated in the cinema, in the HD studio, and in the home viewing environment. He will introduce methods that may be used to achieve wide colour gamut, and discuss the colour parameters in the recent BT.2020 standard for UHD.

Charles will explain several common errors committed by display vendors, and will outline how to mitigate them through calibration or by using external equipment.

At the completion of the webinar, you will have a good understanding of the important colourspaces in high-end content creation, particularly BT.709 and DCI P3. You will have a good understanding of the signal chain for proper decoding and display; you’ll understand how to best bring an uncalibrated or suspect display device into conformance with content creation standards.

Who Should Attend: The Seminar will be suitable for people in positions such as these:

The attendee should be familiar with digital video, and HD. (Knowledge of digital cinema is not required.) Knowledge of mathematics isn’t required; nonetheless, many graphs and several equations will be shown!

Registration: At GoToTraining, CAD 240. Detailed handout notes – some of which form portions of the second edition of Mr. Poynton’s book – will be provided. For information, contact Charles Poynton, charles@poynton.com, +1 416 535 7187.

Copyright © 2013-12-09 13:02 EST
Charles Poynton