Colour management is a key component of imaging applications. Generally speaking, it consists of tools to unambiguously reproduce and transform colour image data between input devices, storage facilities, and output devices. The data is usually (though not always) described as coordinates in a given colour space. ICC profiles specify how to transform them between this colour space (e.g. one describing your camera's gamut) and an intermediate, device-independent colour space.

A staple of analog and digital broadcasting, the YCbCr colour space is defined in three distinct International Telecommunications Union recommendations (ITU-R): BT.601-7, BT.709-6, and BT.2020-2. Colour management systems such as Little CMS have long supported it, even though it may well be the only colour space that cannot be tested properly. This is because there are no ICC profiles in the wild that target it; except for two such copyrighted specimens, scraped a long time ago from Sun machines, and lost to the mists of time.

This talk will show you how I fixed this. I will showcase the essentials of colour management, the standards describing the YCbCr colour space, and how to go from its specification to an ICC profile implementing such a transformation.

(Image is Simon A. Eugster, Public domain, via Wikimedia Commons.)