PUB423_digital camera.pdf (181.78 kB)
A study of digital camera colorimetric characterisation based on polynomial modelling
journal contributionposted on 2006-06-07, 12:16 authored by Guowei Hong, M. Ronnier Luo, Peter A. Rhodes
The digital camera is a powerful tool to capture images for use in image processing and colour communication. However, the RGB signals generated by a digital camera are device-dependent, i.e. different digital cameras produce different RGB responses for the same scene. Furthermore, they are not colorimetric, i.e. the output RGB signals do not directly correspond to the device-independent tristimulus values based on the CIE standard colorimetric observer. One approach for deriving a colorimetric mapping between camera RGB signals and CIE tristimulus values uses polynomial modelling and is described here. The least-squares fitting technique was used to derive the coefficients of 3× n polynomial transfer matrices yielding a modelling accuracy typically averaging 1 Δ E units in CMC(1:1) when a 3× 11 matrix is used. Experiments were carried out to investigate the repeatability of the digitising system, characterisation performance when different polynomials were used, modelling accuracy when 8-bit and 12-bit RGB data were used for characterisation and the number of reference samples needed to achieve a reasonable degree of modelling accuracy. Choice of characterisation target and media and their effect on metamerism have been examined. It is demonstrated that a model is dependent upon both media and colorant and applying a model to other media/colorants can lead to serious eye-camera metamerism problems.
CitationHONG, LUO and RHODES, 2001. A study of digital camera colorimetric characterisation based on polynomial modelling. Color Research and Application, 26(1), pp. 76-84
Publisher© John Wiley & Sons
NotesThis article was published in the journal, Color Research and Application [© John Wiley & Sons].