步进式序列虹膜图像质量评价

在虹膜识别系统中,质量较差的虹膜图像可能被系统拒识,导致身份识别或身份认证的失败.因此有必要在虹膜图像的采集端引入质量评价环节,从虹膜图像采集仪输出的视频序列中挑选出符合识别系统要求的虹膜图像.为了减少序列图像质量评价的时间,根据图像的性质,对输入的序列图像进行步进式质量评价,不同的阶段设置不同的门限,只有满足要求的图像才能进入下一阶段的评价,这样将大大减少进行全部步骤评价的图像数量,能有效缩短序列图像评价的时间,保证了选取图像的质量和速度.试验结果表明,该算法能够有效地选择符合质量要求的虹膜图像.

Stepwise Quality Evaluation of the Sequence Iris Images

Iris images with bad quality will be rejected by the automatic iris recognition system,which will result in the failure of identification or verification.Therefore it is necessary to introduce the quality evaluation process of iris images in the phase of image acquisition,which aims to pick out the iris images with high quality from the video sequences captured by the image acquisition devices.This paper carries out quality evaluation of input sequence images according to the characteristics of images.Different thresholds are established in different stages,and only the images that meet the needs of the thresholds are able to enter the next evaluation stage.In this way,evaluation time for the sequence images is reduced effectively,and the quality and speed of selected images can be guaranteed.The experimental results show that the new algorithm is effective to pick out the iris images with high quality.