摘要

Print mottle is problematic in the print and paper industry. In this report, a mathematical evaluation model of print mottle was generated after analyzing several methods. The print mottle images can be evaluated by the model based on the theory of wavelet image denoising analyses that use the wavelet multi-scale fast algorithm. The model was then applied to analyze print mottle on four business papers (inkjet papers, newsprint papers, art papers, and double-coated offset printing papers). The correlation between the results of this method and the human visual evaluation system (HVS) was calculated and evaluated. Experimental results showed that the model predictions agreed with HVS results. The correlation between the printed newsprint papers and the eight different wavelet base functions was over 0.76 (such as haar, sym4, bior3.7, etc.) and decomposed at the first, second, and third levels. The results of the three other papers were better matched with the analysis by human eyes, but the correlation of the art paper and visual model were not as strong as the others. The optimal parameters for the print mottle model were presented in the four kinds of papers presented.