REFLECTANCE SPECTRA ESTIMATION AND COLOUR SPACE CONVERSION USING REFERENCE REFLECTANCE SPECTRA

摘要

A Personal Computer (PC) (2) adjusts a colour of an image received from a digital camera (3) to produce an estimated reflectance spectrum and/or to convert the colour to a new colour space. First, an input compensation transform is generated, e.g. based on a Macbeth colour chart in the image, to compensate for the sensitivity of the camera (3) used to generate the image to different wavelengths of light and the illumination spectrum incident on an object of interest to which the image relates. In order to estimate the reflectance spectrum, a reflectance spectrum estimation transform is then generated by the PC (2). In order to convert the colour of the image to the new colour space, a colour space conversion transform is generated by the PC (2). Both the reflectance spectrum estimation transform and the colour space conversion transform are based on the input compensation transform and reference reflectance spectra stored in a reference reflectance spectra database (4).