BFD(l:c)colour‐difference formula Part 1ndashDevelopment of the formula

Abstract

The available experimental data relating to small colour differences between pairs of surface colours have been combined together into sets including perceptibility results and acceptability results. Supplementary experiments have been carried out to enable all the previous visual results to be brought on to a common scale, and to provide extra information when this was considered necessary. A new colour‐difference formula, BFD(l:c), has been developed using the combined experimental results. Various aspects of colour differences have been considered in turn to decide the form of formula required, and the constants in the formula have been optimised using the combined perceptibility and acceptability results. The new formula is similar in structure to the CMC(l:c) formula in most respects. However, it was found that a new term was required to take account of the fact that when chromaticity discrimination ellipses calculated from experimental results are plotted in a b space, they do not all point towards the neutral point. The experimental results were not very consistent with respect to possible tilting of discrimination ellipsoids relative to the xy plane. Overall it seems that any such tilting is quite small and in the direction implicit in the CMC and BFD formulae. Experimental results based on both acceptability and perceptibility judgements form part of the same overall pattern except for the weighting of lightness differences relative to hue and chroma differences.

The impact of color combinations on the legibility of a Web page text presented on CRT displays

“…Many other color difference formulas have been developed in the color difference research, i.e. CMC (Clarke et al, 1984), CIE94 (CIE, 1995), BFD (Luo and Rigg, 1987), and CIEDE2000 (Luo et al, 2001), but are not taken in consideration in this work. The polarity is a property of a color combination defined by the luminance ratio between background and text colors.…”

Measuring color differences in gonioapparent materials used in the automotive industry

“…Table 1 also shows that WSTRESS is always lower than STRESS, which means that the average similitude between perceived (ΔV) and computed (ΔE) color differences increases when a lower weight is assigned to the color pairs with higher uncertainty in observers' visual assessments. Color-Difference Formula STRESS WSTRESS CIELUV [2] 33.4 29.7 CIELAB [3] 35.0 32.6 CMC [4] 40.8 33.8 BFD [5] 43.4 34.2 CIE94 [6] 36.2 34.2 CIEDE2000 [7,11] 32.0 28.1 DIN99d [8] 31.5 28.4 AUDI2000 [14] 27.3 23.9 CAM02-SCD [9] 28.6 24.2 CAM02-UCS [9] 29.3 24.8 OSA-GP-Euclidean [10] 40.6 31.2…”

“…For example, in the automotive industry, the different parts of cars are produced by different manufactures using different materials, and reliable color-difference formulas are necessary for automatic pass/fail color decisions. In the past years, a number of color-difference formulas have been proposed for industrial applications [2][3][4][5][6][7][8][9][10].…”

Multi-level contrast filtering in image difference metrics

“…In 1987, Luo and Rigg [11,12] proposed the BFD color difference formula providing a correction of the CMC formula in the blue region. In 1994, CIE proposed the non-Euclidean formula E 94 [13] by introducing a local metric tensor in the CIELAB space in analogy with the CMC formula.…”