在文件检验工作中,检验人员时常会碰到压印力量较小、印文纸张文字花纹干扰强的钢印印文。通过传统方法难以将该类钢印印文清晰的呈现出来。为了更好的解决上述疑难问题,本文通过使用反射变换成像（RTI）技术有效提高了钢印印文图像的清晰度。RTI技术除了传统的图像数据采集以外还通过数字方法增强物体表面的形状与颜色属性。通过RTI技术处理后的钢印印文更有利于直观比对检验和重合比对检验,为钢印印文检验找到了有力解决手段。

In the document examination, inspectors often encounter the printed texts difficult to identify because of the interference from paper pattern and/or overlapping printed words. It is not easy for conventional methods to make it seen clear of the printed text that is produced with steel seal in occurrence of the above impediments. These problems can be resolved with the reflectance transformation imaging (RTI) to improve the resolution of the image. With the RTI software, operators, using the interactive device, can reproduce the resultant image through changes of incident light. In addition to the traditional image data acquisition, RTI processing can enhance the properties of shape and color of an object’s surface by the digital manipulation, therefore revealing more abundant information of a surface than that obtained by the traditionally empirical handling. In this article, a case, involving with whether two pressed prints are stamped with genuine official steel seal in the certificates of real estate, has been settled with the RTI utilization. The tests were made by first the side light shooting and successively the RTI procedure, with the RTI choice to be collecting more information of the pressed prints and more obvious of the background contrast and easier of carrying out plus more convenient of superposition and intuitive comparison of the tested materials. In conclusion, RTI can play its vigorous role at solving the difficulty in recognizing the printed texts with the interference of the paper pattern and/or overlapping printed words during the steel seal pressing.