Department of Color Physics, Institute for Color Science and Technology
Department of Textile Engineering, Amirkabir University of Technology
In this paper, the spectral dimensions of two sets of samples including 457 black and 84 white fabrics are compared. White fabrics are treated with variety of fluorescent whitening agents and the blacks are fabrics that dyed with different combinations of suitable dyes and pigments. In this way, the reflectance spectra of blacks as well as the total radiance factors of whites are compressed in one to five compressed spaces using the principal component analyzing technique. The reduced data are then reconstructed and the averages of the percentile relative root mean square errors between the actual and the recovered spectra of each dataset are calculated to show the spectral dimensionality of both groups through the analyzing of spectral errors. Besides, the colorimetric errors between the actual and the compressed-reconstructed spectra are represented by the mean values of ΔE00 color difference values under D65 illuminant and 1964 standard observer. Results show that the total radiance factors of white samples are smoother than the reflectance spectra of blacks and could be adequately described in a 2 dimensional space, while blacks need to be characterized in higher dimensions i.e., 4, to approximately provide same cumulative energy content as well as spectral and colorimetric errors.