Reproducibility improvement in color measurements of periodic objects

A common and known problem in textile industry is the measurement of color of their fabrics for quality control. Commercial equipment is limited to color measurements of objects with homogeneous surfaces. In the case of samples with no-homogeneous surfaces it is recommended the use of accessories such as an integrating sphere that averages the in-homogeneities along with the averaging of several measurements taken for different orientations of the sample. However, single measurements with these devices are still not precise enough. In order to solve this problem we proposed a novel system for color measurement of periodic objects. In a first stage we have presented novel illumination geometry capable to produce an homogeneous illumination over periodic objects. The measurements were made with a two-aperture radiometer which is coupled to the illumination setup. This system was used to measure the reflectance produced by a textile sample. In this w ork, w e p resent the second s tage, where the system is improved in order to measure color directly from textile samples. We present the results from a comparison between our system and a commercial one.