Data-Driven Segmentation of Post-mortem Iris Images

This paper presents a method for segmenting iris images obtained from the deceased subjects, by training a deep convolutional neural network (DCNN) designed for the purpose of semantic segmentation. Post-mortem iris recognition has recently emerged as an alternative, or additional, method useful in forensic analysis. At the same time it poses many new challenges from the technological standpoint, one of them being the image segmentation stage, which has proven difficult to be reliably executed by conventional iris recognition methods. Our approach is based on the SegNet architecture, fine-tuned with 1,300 manually segmented post-mortem iris images taken from the Warsaw-BioBase-Post-Mortem-Iris v1.0 database. The experiments presented in this paper show that this data-driven solution is able to learn specific deformations present in post-mortem samples, which are missing from alive irises, and offers a considerable improvement over the state-of-the-art, conventional segmentation algorithm (OSIRIS): the Intersection over Union (IoU) metric was improved from 73.6% (for OSIRIS) to 83% (for DCNN-based presented in this paper) averaged over subject-disjoint, multiple splits of the data into train and test subsets. This paper offers the first known to us method of automatic processing of post-mortem iris images. We offer source codes with the trained DCNN that perform end-to-end segmentation of post-mortem iris images, as described in this paper. Also, we offer binary masks corresponding to manual segmentation of samples from Warsaw-BioBase-Post-Mortem-Iris v1.0 database to facilitate development of alternative methods for post-mortem iris segmentation

The impact of collarette region-based convolutional neural network for iris recognition

Iris recognition is a biometric technique that reliably and quickly recognizes a person by their iris based on unique biological characteristics. Iris has an exceptional structure and it provides very rich feature spaces as freckles, stripes, coronas, zigzag collarette area, etc. It has many features where its growing interest in biometric recognition lies. This paper proposes an improved iris recognition method for person identification based on Convolutional Neural Networks (CNN) with an improved recognition rate based on a contribution on zigzag collarette area - the area surrounding the pupil - recognition. Our work is in the field of biometrics especially iris recognition; the iris recognition rate using the full circle of the zigzag collarette was compared with the detection rate using the lower semicircle of the zigzag collarette. The classification of the collarette is based on the Alex-Net model to learn this feature, the use of the couple (collarette/CNN) allows for noiseless and more targeted characterization and also an automatic extraction of the lower semicircle of the collarette region, finally, the SVM training model is used for classification using grayscale eye image data taken from (CASIA-iris-V4) database. The experimental results show that our contribution proves to be the best accurate, because the CNN can effectively extract the image features with higher classification accuracy and because our new method, which uses the lower semicircle of the collarette region, achieved the highest recognition accuracy compared with the old methods that use the full circle of collarette region

MENTOR: Human Perception-Guided Pretraining for Iris Presentation Detection

Incorporating human salience into the training of CNNs has boosted performance in difficult tasks such as biometric presentation attack detection. However, collecting human annotations is a laborious task, not to mention the questions of how and where (in the model architecture) to efficiently incorporate this information into model's training once annotations are obtained. In this paper, we introduce MENTOR (huMan pErceptioN-guided preTraining fOr iris pResentation attack detection), which addresses both of these issues through two unique rounds of training. First, we train an autoencoder to learn human saliency maps given an input iris image (both real and fake examples). Once this representation is learned, we utilize the trained autoencoder in two different ways: (a) as a pre-trained backbone for an iris presentation attack detector, and (b) as a human-inspired annotator of salient features on unknown data. We show that MENTOR's benefits are threefold: (a) significant boost in iris PAD performance when using the human perception-trained encoder's weights compared to general-purpose weights (e.g. ImageNet-sourced, or random), (b) capability of generating infinite number of human-like saliency maps for unseen iris PAD samples to be used in any human saliency-guided training paradigm, and (c) increase in efficiency of iris PAD model training. Sources codes and weights are offered along with the paper.Comment: 8 pages, 3 figure