光栅防伪技术由于成本低、适用范围广、呈现方式多样, 被广泛应用于印刷产品的防伪中。基于单重光栅防伪方法, 探索了多重光栅解码下隐藏信息的三维显示方法, 分析了不同加网线数、网点面积率、隐藏信息在色版中的嵌入距离差和嵌入顺序等参数对图像的隐藏和显示效果的影响。在此基础上, 以隐藏和显示的三维效果的最佳参数为依据, 进行了实际印刷的验证, 实验结果与理论模拟获得一致的效果, 证明了该方法的科学性和实用性, 可用于实际印刷包装品的防伪, 增强产品防伪的效果。

为了准确地预测双面半色调图像的光谱反射率，并考虑光在纸张内的散射和油墨在纸基上的扩展渗透，建立了一个统一的双面半色调图像光谱反射率精确色彩预测模型.在油墨是非散射介质,纸张为强散射体以及油墨和纸张具有相同的折射率的条件下，引入WilliamsClapper模型中光在油墨中斜程传播的思想，考虑进入纸基层的光线横向传播和油墨扩展导致的网点扩大效应以及光在纸基和印刷品空气界面间的多重内反射，利用多重内反射的网状结构分析法和最小二乘曲线拟合方法，确定了各种不同叠印条件下的理论网点面积率和有效网点面积率的函数关系，得出彩色双面图像的光谱反射色彩精确预测模型.新模型的预测值和测量值达到了较好的匹配，同时这也为彩色双面图像的呈色规律分析和印刷品质量检测系统的研制与开发提供了理论依据.

Based on the principle of spatial pyramid for signal, a multi-scale transform of two-dimensional (2D) interpolating pyramid is constructed by the nonlinear median operator. The transform properties of error diffuse halftoning noise on multiple scales are investigated and analyzed through experiments. According to these properties, a robust inverse halftoning method is proposed. The halftoning image is firstly preprocessed by a Gaussian low-pass filter, and decomposed by the one-scale transform. Then a Wiener filter is employed to the detailed coefficients. Finally an inverse image is reconstructed. Experimental results show that the proposed transform has the advantage of separating the halftoning noise and image detail over linear multi-resolution transform. The presented inverse halftoning method performs some excellent abilities on sharp edge, high peak signal-to-noise ratio (PSNR), and small memory requirement.