Why use iccMAX profiles?
ICC recommends profiles made according to the v4 specification
for most workflows, as it supports consistent results in today's open and cross-platform color management systems.
To achieve this consistency, it was necessary to define a fixed Profile Connection Space, so that the data to which a profile is assigned is always interpreted in the same way. The PCS was chosen to be based on the CIE 1931 Observer and D50 illuminant. Data that has a different colorimetric interpretation - i.e. different illuminants and observers - must be transformed into the ICC PCS by chromatic adaptation.
This basic architecture continues to work well, particularly for its original purpose, which was to communicate colour between devices (especially scanner, camera, display and printer in an office or print production workflow). However, in the 20+ years since the first ICC specification many things have changed, resulting in new users of colour management and new technologies of colour reproduction. Examples of such changes include:
- The motion picture and broadcast industries now use fully-digital workflows from capture and CGI through to post-production and broadcast.
- Consumer photography is mostly based on RGB digital capture and rendering to a reference display, but photographers and cinematographers are also making use of new technologies such as high dynamic range and multispectral imaging.
- Traditional display rendering pathways are often based on a reference display with a limited dynamic range and colour gamut. Modern displays significantly exceed these limits, and to make best use of them it is necessary to communicate actual gamuts and apply suitable tone and gamut mapping.
- Medical practitioners increasingly view digital images rather than radiological films or biological samples, and there is increasing use of colour displays for this purpose.
- Digital printing is now used as a core production technology for many non-paper materials, including ceramics, textiles, laminates as well as additive manufacturing (3D printing).
- The packaging industry has adopted many innovations in materials and production, and has increasingly complex requirements at design and preview stages.
- Mobile devices, often with no OS-level colour management framework, are now in widespread use for content creation and viewing.
As a result of these changes, many new colour management needs have emerged that cannot be addressed by a fixed colorimetric PCS. ICC has addressed these by introducing a powerful and highly flexible extension to v4, known as iccMAX
. As well as flexibility in the connection space, iccMAX incorporates many new data types (including high-precision integer and floating point), the ability to actually program the conversion within the profile, and many other new features.
Benefits that users will see with iccMAX include:
- The ability to use spectral data
- The ability to use different illuminants and observers without the need for chromatic adaptation
- The ability to encode complex transforms, including functional transforms, in the profile
- Better handling of spot colours
- Compatibility with v4 profiles
- More support for total colour appearance, including texture and gloss
- Better applicability to a wide range of industries, including medical imaging, motion picture, fine art, package printing and photography
An example that illustrates the limitations of v4 and the extended functionality of iccMAX is a modern package design. Incorporating many different inks, including metallics and fluorescent, together with fine surface texture and gloss varnish or laminate, the preview in a v4 system is limited to a single viewing condition of light source and viewing angle, and cannot predict how the non-process colours will overprint. Using iccMAX, it is now possible to fully predict the final appearance of the package under different light sources and viewing angles, making it possible for a developer to build a realistic 3D previewing system.
- iccMAX provides value to end users by providing a framework to process images in a way that was not possible with ICC v4, and hence to use a range of well-established tools instead of having custom tools developed from scratch. Example profiles that address many current real-world problems, and tools to create and use the new profiles, are freely available in the iccMAX reference implementation, and vendors will build on these to provide turn-key solutions for a wide range of needs.
- iccMAX provides value to developers by giving them a comprehensive suite of code, examples and tools in the reference implementation, which makes it possible to solve real-world problem in a highly efficient way. The reference code, and applications and profiles generated through its use, are free to distribute under open source license.
Read more about iccMAX in the value chain
iccMAX overview by William Li (ICC co-chair)
Life of a color: color management and iccMAX by Max Derhak (ICC co-chair)