An improved method for visual gamma correction is developed for LCD displays to increase the accuracy of digital colour reproduction. Rather than utilising a photometric measurement device, we use observers’ visual luminance judgements for gamma correction. Eight half tone patterns were designed to generate relative luminances from 1/9 to 8/9 for each colour channel. A psychophysical experiment...

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 tris...

The present study reports physicochemical characterization and antioxidant activity of essential oils extracted from guggul (Commiphora wightii) exudates collected from different places in Madhya Pradesh, India. The guggul exudates were hydrodistilled for 3-4 h in Clevenger apparatus. The oil obtained was dried over anhydrous Na2SO4 and stored at 4° until testing. Before extraction of oils from...

Reflectance models of halftone images, such as the Murray-Davis equation for monochrome and the Neugebauer equations for color, generally are not satisfactory predictors of average reflectance or tristimulus values (TSVs), even when used with the Yule-Nielsen nfactor. CIE colorimetric measurements of halftone dots and the paper between the dots for cyan, magenta, and yellow wax thermal transfer...

The primary goal of a colour characterization model is to establish a mapping from digital input values di (i=R,G,B) to tristimulus values such as XYZ. A good characterization model should be fast, use a small amount of data, and allow for backward mapping from tristimulus to di. This paper demonstrates implementations of three different colour characterization models, each tested on seven disp...

This study proposes a feasible method for spectral color reproduction based on a node address array selection technique from CIE tristimulus values. In this method three-dimensional lookup table (3-D LUT) has been constructed to connect the node address array and the spectrum as the source and destination spaces. First we present a general framework for how to reproduce spectral color. Then res...

It is essential to understand the consumption pattern of food and how it changes over time to formulate sound economic policies as well as marketing and pricing strategies. In this study, we estimate the Quadratic Almost Ideal Demand System with six rounds of the Family Income Expenditure Survey exploiting the conditional linearity of the demand system. We find that the Filipino diet has become...

Tristimulus colorimetry and diffuse reflectance spectroscopy (DRS) are white-light skin reflectance techniques used to measure the intensity of skin pigmentation. The tristimulus colorimeter is an instrument that measures a perceived color and the DRS instrument measures biological chromophores of the skin, including oxy- and deoxyhemoglobin, melanin and scattering. Data gathered from these too...