| Abstract: | The visual assessment of small colour differences still plays a large part in the determination of the acceptability of industrial products, particularly textiles. For several reasons, which are discussed, many advantages would accrue from the replacement of visual methods by instrumental ones. The general features of both visual assessment and instrumental measurement are given, and the types of approach in attempts to correlate the twoare discussed. Visual assessments vary greatly, depending on the viewing conditions, so several different correlations have been made in the form of colour-difference equations. Although a particular equation might provide a good correlation for particular viewing conditions, the usual conditions under which the better-known equations have been established do not correspond to those used in industry. These points have been elaborated to provide the relevant background to the report of work carried out under the direction of the Society's Colour Measurement Committee. |
