Mutsuko Nichogi

Color management system with multilayer perceptrons

This paper has two objectives. The first is to explain our color reproduction procedure, especially our new gamut check and mapping method and comparative experimental results on it. The second is to discuss availability and effectiveness of multilayer perceptron (MLP) in the color reproduction fields. We will show problems and merits of MLP and its learning through experiments.

Network color management system using a cluster dividing method

Recently the color reproduction of the real objects is becoming more and more important in the field of telemedicine and internet shopping. To reproduce the objects color under the various conditions, the surface spectral reflectance has to be estimated. In this paper we present the novel way to estimate it using conventional 3- band digital camera. Usually the precise estimation of the spectra from the 3-band image is very difficult, as it has metameric black and the simple camera model is not suitable. To improve the estimation accuracy, we propose dividing color space in to clusters and estimating spectra using different model parameters at each cluster. Clusters are set corresponding to the major objects in camera images. Next the estimated spectral image is reproduced on the monitor. When luminance and color temperature of the specified viewing illuminant and the monitor are different, the subject hardly perceives the objects real color. Therefore the image is converted using CIECAM97s. This paper shows the results of simulation using the image of enlarged humans mouth assuming remote consulting with dental clinic. In this system, a dentist can perceive the real color of patients gums and teeth on the monitor.