Mathematical approach for predicting non-negative tristimulus values using the CAT02 chromatic adaptation transform
Contribuinte(s) |
Universidad de Alicante. Departamento de Óptica, Farmacología y Anatomía Liaoning University of Science and Technology. Department of Computer Science University of Leeds. Department of Colour Science Visión y Color |
---|---|
Data(s) |
20/09/2011
20/09/2011
2011
28/07/2011
|
Resumo |
It has been reported that for certain colour samples, the chromatic adaptation transform CAT02 imbedded in the CIECAM02 colour appearance model predicts corresponding colours with negative tristimulus values (TSVs), which can cause problems in certain applications. To overcome this problem, a mathematical approach is proposed for modifying CAT02. This approach combines a non-negativity constraint for the TSVs of corresponding colours with the minimization of the colour differences between those values for the corresponding colours obtained by visual observations and the TSVs of the corresponding colours predicted by the model, which is a constrained non-linear optimization problem. By solving the non-linear optimization problem, a new matrix is found. The performance of the CAT02 transform with various matrices including the original CAT02 matrix, and the new matrix are tested using visual datasets and the optimum colours. Test results show that the CAT02 with the new matrix predicted corresponding colours without negative TSVs for all optimum colours and the colour matching functions of the two CIE standard observers under the test illuminants considered. However, the accuracy with the new matrix for predicting the visual data is approximately 1 CIELAB colour difference unit worse compared with the original CAT02. This indicates that accuracy has to be sacrificed to achieve the non-negativity constraint for the TSVs of the corresponding colours. |
Identificador |
LI, Changjun, et al. “Mathematical approach for predicting non-negative tristimulus values using the CAT02 chromatic adaptation transform”. Color Research & Application. Article first published online: 28 Jul. 2011. ISSN 1520-6378 1520-6378 (Online) 0361-2317 (Print) http://hdl.handle.net/10045/18684 10.1002/col.20694 |
Idioma(s) |
eng |
Publicador |
Wiley Periodicals |
Relação |
http://dx.doi.org/10.1002/col.20694 |
Direitos |
© 2011 Wiley Periodicals, Inc. The definitive version is available at http://www3.interscience.wiley.com/ info:eu-repo/semantics/restrictedAccess |
Palavras-Chave | #Chromatic adaptation transform #CAT02 #CIECAM02 #Corresponding colour #Tristimulus values #Óptica |
Tipo |
info:eu-repo/semantics/article |