对影响激光打印文件上暗码点提取因素的实验研究

Experimental Study of Factors Affecting the Extraction of Tracking Dots on Laser Printing File

目的:获取整幅A4纸上完整暗码点图案,为利用暗码点对彩色激光打印文件检验鉴定提供前处理工作,并对得到的暗码点图案进行解析。方法:采用MATLAB程序和Photoshop图像处理软件两种方法提取彩色激光打印文件上的暗码点,对影响提取暗码点的因素进行实验研究。结果:暗码点的提取主要受打印纸张的白度、打印文件内容、打印机本身、扫描仪分辨率、容差设置等因素的影响,HP CP5525dn、HP CP4525dn打印机打印文件上暗码点包含品牌信息、不包含时间信息,依据提取到的暗码点可以区分不同品牌以及同一品牌不同型号彩色激光打印文件。

Objective： the whole A4 paper complete tracking dots were got for the use of pre-processing work for color laser printing inspection and identification documents,and resolve tracking dots. Method： Matlab software programs and Photoshop were used to extract the tracking dots from the laser print files. The factors affecting the extraction of tracking dots on laser printing file were studied. Results： The complete extraction of tracking dots is mainly affected by the whiteness of the printing paper,printing contents of the file,the printer itself,scanner resolution and tolerance,the tracking dots of brand message are included but without the time information,the different files printed by different brands and different models of the same brand color laser printer can be distinguished by the extrated tracking dots.