利用CCD 图像捕获设备,把印刷测试图转换为数字图像,采用基于倾斜边缘梯度分析的空间频率响应检测算法,测量获得了印刷复制系统的空间频率响应特性,并把经过人眼视觉系统滤波后得到的空间频率响应曲线内的面积作归一化处理后,所获得的测量值作为清晰度质量描述因子。实验结果表明,清晰度质量描述因子能较好地反映印刷品的清晰度复制质量,提供了一种新的客观、定量检测印刷品清晰度的方法,为实现印刷品质量的自动化检测与评价提供了有力的技术支持。

CCD-based input device was used to convert printing test pattern to digital image. Spatial frequency response characteristics of the printing system were obtained by measurement using spatial frequency response measurement algorithm based on incline edge gradient analysis. The area in spatial frequency response curve obtained from human vision system filtering was normalization processed and the result was used as sharpness quality factor. Experimental results indicated that the sharpness quality factor well reflects the reproduction effect of the prints sharpness, and offers a new way to measure prints sharpness objectively and quantitatively. The purposed was to provide technical support for automatic measurement and evaluation of printing quality.