基于计算光场成像的曲面客体表面指纹提取

Extracting Fingerprints from Surface of Curved Objects Using Computational Light-Field Imaging

指纹具有的唯一性和终身不变性使其在刑侦检测和身份识别等领域具有广泛应用。传统指纹提取方式会破坏原始指纹,因此,近年来多采用刑侦取证相机对指纹进行拍摄、提取。针对一次拍摄不能得到曲面客体表面指纹清晰图像的问题,将计算光场成像引入曲面客体表面指纹的提取中。首先,根据指纹拍摄场景设计指纹光场相机,利用数字重聚焦算法得到指纹图像堆栈;然后,基于图像清晰度评价的图像融合算法得到曲面上各处都清晰的指纹图像。实验结果表明,本方法设计的指纹光场相机及处理算法可以有效提取位于曲面客体表面的指纹。

Fingerprints are widely used in the fields of criminal investigation and identification due to their uniqueness and lifelong invariance.Recently,criminal investigation forensic cameras are commonly used to extract fingerprints by taking photos as the traditional fingerprint extraction methods destroy the original fingerprint.Aiming at the problem that a clear image of the surface fingerprint from a curved object cannot be obtained in one shot,this study introduces the computational light-field imaging for the surface fingerprint extraction from the curved object.First,the fingerprint light-field camera is designed according to the fingerprint-shooting scene and the digital refocusing algorithm is used to obtain the fingerprint image stack.Then,the image fusion algorithm based on the image sharpness evaluation obtains a clear fingerprint image from the curved surface.Experimental results show that the fingerprint light-field camera and processing algorithm designed using the method can effectively extract fingerprints from the surface of curved objects.