一种基于定向反射显现潜在手印及灰尘手印的技术

A Technique for Developing Latent Fingerprints and Dust Fingerprints based on Directional Reflection

通过简单讨论光线的反射原理、定向反射的照相原理以及适用范围,从垂直定向反射和小偏角反射两个角度,对灰尘手印、汗潜手印进行拍照固定,观察照片的亮度反差及手印纹线的清晰程度。在使用定向反射法对手印进行拍照固定时,要控制光斑的大小,调节相机的拍照参数,以增强手印纹线与客体之间的亮度反差,减弱或消除客体背景颜色对手印纹线的干扰。实验结果表明,光学显现法可有效提取高对比亮度反差且乳突纹线清晰连贯的手印照片。此外,该方法是一种无损的手印显现方法,其不会对手印中的DNA生物检材产生任何的影响,使得现场勘查过程中兼顾手印与手印中DNA生物检材的提取成为可能。

By discussing the principle of light reflection, the photographic principle of directional reflection and the scope of application, the dust fingerprints and sweat latent fingerprints are photographed and fixed from the angles of vertical directional reflection and small deflection angle reflection, and the brightness contrast and the clarity of fingerprint lines are observed. When fixing fingerprints by directional reflection method, we should control the size of light spot and adjust the photographic parameters of the camera to enhance the brightness contrast between fingerprints and objects, and reduce or eliminate the interference of background color of objects on fingerprints. The experimental results show that the optical rendering method can effectively extract handprints with high contrast brightness contrast and clear and coherent mastoid lines. In addition, this method is a non-destructive fingerprint display method, which will not have any impact on DNA biological samples in fingerprints, making it possible to take into account the extraction of DNA biological samples in both fingerprints and fingerprints in the process of on-site investigation.