共查询到18条相似文献,搜索用时 46 毫秒
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对基于数字图像处理的网点面积率检测算法进行了探讨,给出了算法工作流程并建立了模型。最后通过实验对算法进行了验证。 相似文献
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喷墨数码印刷品网点扩大值和标定网点面积率间关系的研究 总被引:1,自引:3,他引:1
鉴于目前喷墨数码印刷品质量评价体系尚未建立,采用模型实验法讨论喷墨数码样张上网点扩大值和标定网点面积率间关系,建立起网点扩大值和标定网点面积率间的回归方程,为建立喷墨数码印刷品质量评价标准提供理论和实践基础. 相似文献
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基于光散射概率函数的半色调反射率模型 总被引:1,自引:1,他引:1
目的以调幅和调频网点为研究对象,针对2种网点分别建立半色调反射率模型,并将网点结构的差异引入模型。方法基于Murray-Davies模型理论推导半色调反射率模型,并以不同光散射概率函数体现不同网点结构。采用数学显微采集系统对半色调印品进行了数字化采集,将数字图像灰度值转化为对应的反射率值,通过分析反射率直方图极值特征得到半色调印品空白反射率和着墨部分反射率,再经数据拟合确定理论推导模型中的参数。结果基于总反射率和光谱反射率的验证实验,结果表明调幅和调频网点模型拟合优度判定系数R2分别为0.9821和0.9520。结论所建立模型能够体现网点结构的差异,精度高,适用性强。 相似文献
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目的研究印刷品网点扩大中光学网点扩大特性,量化分析不同类型网点结构对光学网点扩大的影响差异,探讨光学网点扩大的一般规律。方法根据网点结构,提出周长对网点面积率敏感度的定义,以此分析光学网点扩大随网点结构特性的变化规律,图象栅格化处理器(RIP)输出多种网点结构,以不同网点胶印样张形式验证光学网点扩大规律。结果对于调幅网点,光学网点扩大大于机械网点扩大;对于调频网点,机械网点扩大大于光学网点扩大。同心圆网点是一种特殊网点结构,兼有调幅、调频光学扩大特性。结论光学网点扩大不可避免,光学网点扩大值与周长对面积率敏感度正相关,研究不同网点结构的光学扩大特性对印刷品质量控制有一定意义。 相似文献
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目的 研究非规整的墨点(非二值理想墨点)形态对光谱反射率的影响, 为预测模型的理论研究提供一个新的思路。方法 通过讨论墨点的非规整形态对网点大小、 厚度及油墨透射率的影响, 采用二维高斯函数模拟墨点表面的形态, 由此建立一个Clapper-Yule扩展模型。结果 模型的数值模拟结果表明墨点的非规整性导致了网点的物理扩大, 增加了油墨对光的吸收, 降低了最终的光谱反射率。结论 采用Clapper-Yule分程模型对颜色进行预测时需考虑墨点的非规整所带来的物理网点扩大, 该模型适用于单色半色调的颜色预测与控制。 相似文献
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首先详细介绍了经典的Clapper-Yule模型以及其改进模型,然后结合半色调印品对这两种模型进行了验证.实验表明:改进的Clapper-Yule模型具有较高的颜色预测精度,可以精确的预测出半色调印品的颜色,从而指导颜色工作者进行颜色参数调节,达到提高印品质量的目的. 相似文献
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In this paper, we propose a Bayesian statistical approach to cycle time modeling. Three models of cycle time in complex manufacturing environments are proposed. These models capture changes in cycle time mean and variance at different levels of work-in-process. We model cycle time mean during a period as a two-segment piecewise linear function of the period's work-in-process and consider three variance models. The challenge is to estimate the breakpoint between the two segments, and the parameters of each model. To accomplish this, we use the Gibbs sampler and Metropolis-Hastings algorithm to perform a Bayesian analysis. With three competing models, Bayesian model selection is used to identify the most plausible and model averaging is performed on the selected model. We compare the resulting model to an analytical non-linear model on an example and provide some insights. 相似文献
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《Drug development and industrial pharmacy》2013,39(3):487-499
AbstractBased upon Okusa's observation (Chem. Pharm. Bull. 1975) that the slopes of a linear plot of logo log fraction of active substance degraded vs log time for first order decay kinetics and a linear plot of log of drug remaining vs log time for a zero order decay kinetics are both unity, an algorithm has been developed to resolve both the energy of activation (E) and the rate constant (Ko or Lo) at the desired shelf-life temperature (To) by analysis of the y-intercepts of parallel slopes at more than one elevated temperature (T).Preliminary estimates of both E and either Ko or Lo are then substituted into a series of mathematical expressions based upon well known Arrhenius relationship:k = A ·exp -E/1.987) (1/T-l/To) where A = Ko or LoUsing converging and interative techniques to treat elevated temperature data, the resulting mean loss rate (eithri Ko or Lo at the designated shelf-life temperature plus a residual error term thus obtained, is used to distinguish statistically between zero and first order treatments. A program called POTENCYLOSS, based upon the algorithm, has been written in business BASIC language for use with an IBM-PC micro-computer.The program is ideally suited for use in preformulation studies or in assigning provisional expiration dating and overage requirements during the early stages of formulation development when there is limited potency stability test data available at accelerated, elevated temperature storage conditions. 相似文献