基于图像处理的数字印刷线条质量检测方法研究

从 ISO 13660 标准定义的数字印刷品线条质量的客观测量指标出发,从图像处理的角度,分析了各个主要质量指标的测量方法。 一方面,按照 ISO 13660 的规定,使用扫描仪以 600 dpi 获取需要测量的图像,然后通过 Hough 变换、边缘跟踪、直线拟合等手段对线宽、粗糙度、模糊度等各个指标进行分析计算;另一方面,通过函数拟合建立了灰度值与密度值之间的关系,实现了 ISO 13660 中关于暗度的计算。 最终选取 5 组样本,以验证算法效果,结果表明该算法能够较好地实现对数字印刷线条质量各个指标的测量计算。

Research on Measurement Method of Digital Printed Line Quality Based on Image Processing

According to the objective measurement indexes of digital printed line quality defined in ISO 13660 standard, the measuring method of each main quality indicator was analyzed. On the one hand, the required 600 dpi measuring image was obtained by scanner on the basis of the rules in ISO 13660 standard. Then the indicators such as line width, raggedness, blurriness and so on were analyzed and calculated by means of Hough transform, edge tracing, and lines fitting. On the other hand, the relationship between gray value and density value was established through function fitting, which made the calculation of opacity in ISO 13660 standard come true. At last, the algorithm was tested through selecting five samples. Experimental results showed that the algorithm can better realize the measurement and calculation of each line quality indicator.