喷墨打印半色调混合像元的反射光谱形态特征研究

Study of The Morphological Character of Spectral Reflectance of Mixed Pixels with Ink-jet Print

对不同的半色调混合像元比例通过彩色喷墨打印机输出后的光谱反射率曲线的光谱形态特征进行了研究。选择反射光谱形态指标,分析了125组不同半色调混合比例下光谱混合像元反射光谱形态指标的变化规律。研究结果表明,半色调混合元的光谱形态指标与半色调混合像元的比例间存在明显的关系;选择分析的4个光谱形态指标之间存在着较大的相关性,按照0.05及以上置信水平和相关系数>0.9的条件对光谱形态指标进行剔除,确定了不同基色不同特征波段中的有效光谱形态指标;在不同波段范围内,各光谱形态指标随半色调混合像元比例的变化规律存在差异性;使用回归分析,各基色特征波段的光谱形态指标与半色调混合比例符合一次线性与二次多项式关系,R^2可达到0.9以上。

Under the experimental condition,different halftone mixed pixel samples were printed out with inkjet printer. 125 groups of reflectance spectra of the samples were measured. The morphological character indices were selected and the variation of halftone sample at different component proportion was analyzed. The correlation between the morphological indexes and reflectance spectra of halftone samples is obvious. 4 chosen morphological indices are correlative. After the index whose R2 is greater than 0. 9（ R is correlation coefficient） and confidence level is greater than 0. 05 are removed,the best morphological index is chosen for different character wavelength of different primary color. The variation of different morphological indices in different wavelength is distinct. The relationship between the morphological character of primary color and the component proportion of halftone can be fitted by linear and polynomial curves,and R^2 is greater than 0. 9.