Influence of colour-matching functions on threshold and large colour differences

New deviate observer (JF‐DO) obtained from experimental color‐matching functions for small fields of real observers

“…In each group a different procedure was used, both for the experimental measurements and for the calculation of the corresponding cmf's. Previous works 13,14,18,19 have shown the variability between the cmf's of some of these observers, as well as certain discrepancies with the CIE-1931 Standard Observer and the CIE-1989 SDO. Our work has created the opportunity to generate a new deviate observer (JF-DO) from the new cmf's for small fields of our 9 real observers.…”

“…11 In our laboratories, we have made new experimental measurements of cmf's for small fields using real observers. [12][13][14][15][16][17] These cmf's were determined for two groups of real observers (JAM, MM and CF; AY, JR, MR, JL, JA and FA). In each group a different procedure was used, both for the experimental measurements and for the calculation of the corresponding cmf's.…”

“…That is, the appearance of these negative values is in general due to the fact that the triangle whose vertices are the reference stimuli XYZ established by the CIE 24 does not contain, for certain wavelengths, some zones of the spectral areas corresponding to each real observer, and represented on the plane whose axis is defined by the corresponding chromatic coordinates r(), g(). To resolve this problem, we found a new system of unreal primaries XЈYЈZЈ, [12][13][14]25 in a way similar to that of the system of unreal primaries XYZ CIE 1931, 24 and to which all the cmf's of our new observers have been referred, those of the CIE 1989 SDO and those of Poza-SDO. 9 The following matrix T represents this transformation: In this new system of unreal primaries XЈYЈZЈ, all the cmfЈs of all the observers considered presented positive values in the interval of wavelengths of 400 -700 nm of the visible spectrum (see Tables I-IX).…”

Mathematical determination of the numerical data corresponding to the color‐matching functions of three real observers using the RGB CIE‐1931 primary system and a new system of unreal primaries X′Y′Z′

“…These cmf's have been used by us in several experiments published in different works, 1,2,12 and by other authors [15][16][17] to whom J. A. Martínez had privately communicated the corresponding numerical data, which these authors cite as G94 (Granada '94).…”

“…In our particular case, these are The matrix T allows us to transform the cmf's of our three observers-JAM, MM, CT-and the rest of the classical observers considered: CIE-1931 Standard Observer, the Standard Deviated Observer, the observer proposed by Vos, and the 10 Stiles-Burch observers for small fields-from the RGB CIE-1931 system of primaries to the new system of unreal primaries XЈYЈZЈ, in which the values of the new cmf's of all the observers are positive in the wavelength interval 400 -700 nm of the visible spectrum. 12 Recently, in our laboratory, we have measured 13,14 new cmf's for 6 real observers (AY, JR, MR, JL, JA, FP) for small fields. For this, we used an experimental device and a procedure different from that followed in the present work.…”