After a brief introduction to the principles of colour management of both device dependent and independent systems the principles of scanner and camera characterisation are discussed in relation to the ANSI/ISO tools developed for this purpose. Procedures are outlined for the evaluation of such devices in terms of their ability to provide satisfactory colour reproduction, and then the techniques which may be used to achieve the necessary characterisation are discussed. These include least-squares fitting, nonlinear transformations, dye combination modelling and look-up-tables with interpolation. Many of the important issues associated with characterisation, such as gamut mapping and appearance modelling, are not discussed in this paper but in the paper on printer characterisation also in this issue.
