LCMS2CIELabMBS.BFDdeltaE(Other as LCMS2CIELabMBS) as Double

LCMS2CIELabMBS.CIE2000DeltaE(Other as LCMS2CIELabMBS, Kl as Double = 1.0, Kc as Double = 1.0, Kh as Double = 1.0) as Double

Delta-E 2000 is the first major revision of the dE94 equation. Unlike dE94, which assumes that L* correctly reflects the perceived differences in lightness, dE2000 varies the weighting of L* depending on where in the lightness range the color falls. dE2000 is still under consideration and does not seem to be widely supported in graphics arts applications.

The weightings KL, KC and KH can be modified to reflect the relative importance of lightness, chroma and hue in different industrial applications

LCMS2CIELabMBS.CIE94DeltaE(Other as LCMS2CIELabMBS) as Double

A technical committee of the CIE (TC1-29) published an equation in 1995 called CIE94. The equation is similar to CMC but the weighting functions are largely based on RIT/DuPont tolerance data derived from automotive paint experiments where sample surfaces are smooth.
It also has ratios, labeled kL (lightness) and Kc (chroma) and the commercial factor (cf) but these tend to be preset in software and are not often exposed for the user (as it is the case in Little CMS).

LCMS2CIELabMBS.Clone as LCMS2CIELabMBS

dim l as new LCMS2CIELabMBS(0.1, 0.2, 0.3)
dim k as LCMS2CIELabMBS = l.Clone
MsgBox str(k.L)+" "+str(k.a)+" "+str(k.b)

LCMS2CIELabMBS.CMCdeltaE(Other as LCMS2CIELabMBS, l as Double, c as Double) as Double

In 1984 the CMC (Colour Measurement Committee of the Society of Dyes and Colourists of Great Britain) developed and adopted an equation based on LCH numbers. Intended for the textiles industry, CMC l:c allows the setting of lightness (l) and chroma (c) factors. As the eye is more sensitive to chroma, the default ratio for l:c is 2:1 allowing for 2x the difference in lightness than chroma (numbers). There is also a 'commercial factor' (cf) which allows an overall varying of the size of the tolerance region according to accuracy requirements. A cf=1.0 means that a delta-E CMC value <1.0 is acceptable.
CMC l:c is designed to be used with D65 and the CIE Supplementary Observer. Commonly-used values for l:c are 2:1 for acceptability and 1:1 for the threshold of imperceptibility.

LCMS2CIELabMBS.Constructor(L as Double=0.0, a as Double=0.0, b as Double=0.0)

See also:

• Constructor(other as LCMS2CIELabMBS)

LCMS2CIELabMBS.Constructor(other as LCMS2CIELabMBS)

See also:

• Constructor(L as Double=0.0, a as Double=0.0, b as Double=0.0)

LCMS2CIELabMBS.DeltaE(Other as LCMS2CIELabMBS) as Double

You don't have to spend too long in the color management world before you come across the term Delta-E. As with many things color, it seems simple to understand at first, yet the closer you look, the more elusive it gets. Delta-E (dE) is a single number that represents the 'distance' between two colors. The idea is that a dE of 1.0 is the smallest color difference the human eye can see. So any dE less than 1.0 is imperceptible and it stands to reason that any dE greater than 1.0 is noticeable. Unfortunately it's not that simple. Some color differences greater than 1 are perfectly acceptable, maybe even unnoticeable. Also, the same dE color difference between two yellows and two blues may not look like the same difference to the eye and there are other places where it can fall down. It's perfectly understandable that we would want to have a system to show errors. After all, we've spent the money on the instruments; shouldn't we get numbers from them? Delta-E numbers can be used for:

• how far off is a print or proof from the original
• how much has a device drifted
• how effective is a particular profile for printing or proofing
• removes subjectivity (as much as possible)

LCMS2CIELabMBS.DesaturateLab(amax as Double, amin as Double, bmax as Double, bmin as Double) as Boolean

See also cmsDesaturateLab in LCMS manual.

LCMS2CIELabMBS.XYZ(whitePoint as LCMS2CIEXYZMBS=nil) as LCMS2CIEXYZMBS

Setting WhitePoint to NULL forces D50 as white point.