In this paper we present a method that, given the tristimulus values under a known illuminant, make it possible to compute a reflectance function that is in the range between 0 and 1 of physically admissible values without altering the corresponding tristimulus values. We represent the unknown reflectance function with a three-dimensional linear model. 1. INTRODUCTION A common problem in spectr...

In 1931, the Commission Internationale de l’Eclairage (CIE) recommended a colour specification system. After various additions over the years it now includes a series of colorimetric measures such as the tristimulus values ( XYZ ), chromaticity coordinates, dominant wavelength, and excitation purity for colour specification and colour matching, CIELAB and CIELUV colour spaces for presenting col...

In recent years, in various sectors of our society, there have been nationalist stirrings which were crystallized and articulated by the late Claro M. Recto, There were jealous demands for the recognition of Philippine sovereignty on the Bases question. There were appeals for the correction of the iniquitous economic relations between the Philippines and the United States. For a time, Filipino ...

This paper presents an adaptive method to obtain chromaticity and luminance by using CMOS image sensor under various environments. The image sensor for a use of colorimeter is characterized based on the CIE standard colorimetric observer. We use the method of least squares to derive a colorimetric characterization matrix between camera RGB output signals and CIE XYZ tristimulus values. This pap...

The Bayesian inference approach to the inverse problem of spectral signal recovery has been extended to mixtures of Gaussian probability distributions of a training dataset in order to increase the efficiency of estimating the spectral signal from the response of a transformation system. Bayesian (BIC) and Akaike (AIC) information criteria were assessed in order to provide the Gaussian mixture ...

A simple method of converting scanner (RGB) responses to estimates of object tristimulus (XYZ) coordinates is to apply a linear transformation to the RGB values. The transformation parameters are selected subject to minimization of some relevant error measure. While the linear method is easy, it can be quite imprecise. Linear methods are only guaranteed to work when the scanner sensor responsiv...

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 tristi...

The ultimate goal of spectral imaging is to achieve high spectral accuracy, so that the spectral information can be used to calculate colorimetrically accurate images for any combination of illuminant and observer. A new spectral reconstruction method, called the matrix R method, was developed to reconstruct spectral reflectance factor accurately while simultaneously achieving high colorimetric...