BS ISO 18619:2015 pdf download.Image technology colour management — Black point compensation
1 Scope
This International Standard specifies a procedure, including computation, by which a transform between ICC profiles can be adjusted (compensated) to take into account differences between the dark end of the source colour space and the dark end of the destination colour space. This is referred to as black point compensation (BPC). The relative colorimetric encoding of ICC profile transforms already provides a mechanism for such adjustment of the light (white) end of the tone scale.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and areind ispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 15076-1, Image technology colour management — Architecture, profile format and data structure —Part 1: Based on ICC.1:2010
ICC.1:2001-04, File Format for Color Profiles
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 15076-1 and the following apply.
3.1 DestinationBlackPoint
coordinate representing a dark neutral reproducible colour in the destination colour gamut
3.2 DestinationProfile
ICC profile, containing the transform from profile connection space to the destination device colour space
3.3 SourceBlackPoint
coordinate representing a dark neutral colour in the source colour gamut
3.4 SourceProfile
ICC profile, containing the transform from the source device colour space to the profile connection space
3.5 RenderingIntent
rendering intent of the conversion from a source ICC profile’s colour space to a destination ICC profile’s colour space
3.6 LabIdentityProfile
real or virtual ICC profile that contains a bi-directional (identity) transform between CIELAB and PCSLAB
4 Requirements
4.1 Constraints
The black point compensation procedure defined in this International Specification shall take as its inputs a destination ICC profile, a source ICC profile, and a rendering intent (in this International Standard called DestinationProfile, SourceProfile and RenderingIntent respectively). Applications that apply black point compensation shall support ICC profiles that conform to ISO 15076-1 and ICC profiles that conform to ICC.1:2001-04. NOTE 1 This requirement ensures that processing applications will properly process all Version 2 and Version 4 ICC profiles. NOTE 2 ISO 15076-1 provides a description of source and destination ICC profiles. The rendering intent shall be one of: RelativeColorimetric; Perceptual; or Saturation. The rendering intent used with DestinationProfile shall be the same as the rendering intent used with SourceProfile. Black point compensation is not appropriate for the AbsoluteColorimetric rendering intent. The versions of SourceProfile and DestinationProfile do not need to match. SourceProfile and DestinationProfile types shall be Input, Display, Output, or ColorSpace. The types of SourceProfile and DestinationProfile do not need to match. DestinationProfile shall contain a transform from the ICC PCS encoding to the colour space encoding. The data colour spaces of the SourceProfile and DestinationProfile shall be Gray, RGB, CMYK or CIELAB. The data colour spaces of SourceProfile and DestinationProfile do not need to match. NOTE 3 Some implementations of BPC extend to additional colour spaces or mixed rendering intents. The way in which BPC operates in these cases is outside the scope of this International Standard.
BS ISO 18619:2015 pdf download
