Pupil dynamics are the important characteristics of face spoofing detection.The face recognition system is one of the most used biometrics for authenticating individual identity.The main threats to the facial recognit...Pupil dynamics are the important characteristics of face spoofing detection.The face recognition system is one of the most used biometrics for authenticating individual identity.The main threats to the facial recognition system are different types of presentation attacks like print attacks,3D mask attacks,replay attacks,etc.The proposed model uses pupil characteristics for liveness detection during the authentication process.The pupillary light reflex is an involuntary reaction controlling the pupil’s diameter at different light intensities.The proposed framework consists of two-phase methodologies.In the first phase,the pupil’s diameter is calculated by applying stimulus(light)in one eye of the subject and calculating the constriction of the pupil size on both eyes in different video frames.The above measurement is converted into feature space using Kohn and Clynes model-defined parameters.The Support Vector Machine is used to classify legitimate subjects when the diameter change is normal(or when the eye is alive)or illegitimate subjects when there is no change or abnormal oscillations of pupil behavior due to the presence of printed photograph,video,or 3D mask of the subject in front of the camera.In the second phase,we perform the facial recognition process.Scale-invariant feature transform(SIFT)is used to find the features from the facial images,with each feature having a size of a 128-dimensional vector.These features are scale,rotation,and orientation invariant and are used for recognizing facial images.The brute force matching algorithm is used for matching features of two different images.The threshold value we considered is 0.08 for good matches.To analyze the performance of the framework,we tested our model in two Face antispoofing datasets named Replay attack datasets and CASIA-SURF datasets,which were used because they contain the videos of the subjects in each sample having three modalities(RGB,IR,Depth).The CASIA-SURF datasets showed an 89.9%Equal Error Rate,while the Replay Attack datasets showed a 92.1%Equal Error Rate.展开更多
Human depression patients often show abnormal pupillary reflex with morphological changes in hippo campus and prefrontal cortex.This study aimed to find the relationship between the prolonged pupillary light reflex(PL...Human depression patients often show abnormal pupillary reflex with morphological changes in hippo campus and prefrontal cortex.This study aimed to find the relationship between the prolonged pupillary light reflex(PLR) which had been shown by confined sows with chronic stress or depression and morphological changes in brain,in order to provide theoretical basis for that the confined environment should lead to sows' depression.A total of 637 sows of Durac,Landrace and Large White breeds with various parities were observed,and the pupil light reflex(PLR) was measured and the actual pupillary light reflex time(PLRT) were recorded.All the PLRTs were grouped based on the results of confidence interval:t>10%as group A,5%<t<10%as group B,1%<t<5%as group C and t<1%as group D.Three individuals were randomly selected from each group(12 sows in total) and the white tissues of hippocampus and the prefrontal cortex were prepared for HS staining slices(three slices/per tissue) for observation on tissue structure and pathological changes with high magnification(400X) of electronic microscope.The results showed that in group A(t>10%) pathological change was found in hippocampus,however,as PLRT increased from group B to group D,pathological changes in hippocampus tissues tended to be deteriorated with the increase of inflammatory cells and nuclear pyknosis phenomena.The same as those shown in hippocampus as the increasing of PLRT from groups A to D,more inflammatory cells appeared in prefrontal cortex for groups B and D.The results suggested that the tissue lesions of hippocampus and prefrontal cortex of the confined sows with prolonged PLRT might be the results of chronic stress or depression.展开更多
建立了一种基于图像处理的快速瞳孔直径检测算法,运用此算法提取了反映阿片类药物成瘾人员与正常人对瞳孔光反射变化差异的3个特征值:绝对收缩幅度(absolute amplitude of contraction,AAC)、相对收缩幅度(relative amplitude of contra...建立了一种基于图像处理的快速瞳孔直径检测算法,运用此算法提取了反映阿片类药物成瘾人员与正常人对瞳孔光反射变化差异的3个特征值:绝对收缩幅度(absolute amplitude of contraction,AAC)、相对收缩幅度(relative amplitude of contraction,RAC)和收缩斜率(SCV,slope of contraction velocity);分别研究了成瘾、性别、近视、年龄、睡眠剥夺等因素对于这3个特征值的影响。不同性别、近视人员、睡眠剥夺人员与正常人之间的3个特征值均无显著差异,成瘾人员与之对比均显著减小。老年人相对于正常青年人,3个特征值都明显减小;与成瘾人员相比,仅在RAC值上有显著差异。结果表明,阿片类药物成瘾人员除了与正常人外,也与其他具有潜在影响瞳孔变化因素的非阿片成瘾人员在瞳孔对光反射的特征值上具有显著差异。该研究的实验数据为进一步建立基于检测瞳孔对光反射其直径发生变化的方法来快速、非接触地鉴别出阿片类药物成瘾人员提供了可靠的依据。展开更多
It is well recognized that the direct pupillary light reflex(DPLR)and vision coexist. DPLR disappcars in eyes when they were blind due to diseases of the optic nerve or retina. I found that the reappearance of DPLR pr...It is well recognized that the direct pupillary light reflex(DPLR)and vision coexist. DPLR disappcars in eyes when they were blind due to diseases of the optic nerve or retina. I found that the reappearance of DPLR prior to the recovery of light pcrception in 21 eyes of 12 patients with no light perception caused by acute neuritis. It suggests that both the phenomenons are likely separated.展开更多
基金funded by Researchers Supporting Program at King Saud University (RSPD2023R809).
文摘Pupil dynamics are the important characteristics of face spoofing detection.The face recognition system is one of the most used biometrics for authenticating individual identity.The main threats to the facial recognition system are different types of presentation attacks like print attacks,3D mask attacks,replay attacks,etc.The proposed model uses pupil characteristics for liveness detection during the authentication process.The pupillary light reflex is an involuntary reaction controlling the pupil’s diameter at different light intensities.The proposed framework consists of two-phase methodologies.In the first phase,the pupil’s diameter is calculated by applying stimulus(light)in one eye of the subject and calculating the constriction of the pupil size on both eyes in different video frames.The above measurement is converted into feature space using Kohn and Clynes model-defined parameters.The Support Vector Machine is used to classify legitimate subjects when the diameter change is normal(or when the eye is alive)or illegitimate subjects when there is no change or abnormal oscillations of pupil behavior due to the presence of printed photograph,video,or 3D mask of the subject in front of the camera.In the second phase,we perform the facial recognition process.Scale-invariant feature transform(SIFT)is used to find the features from the facial images,with each feature having a size of a 128-dimensional vector.These features are scale,rotation,and orientation invariant and are used for recognizing facial images.The brute force matching algorithm is used for matching features of two different images.The threshold value we considered is 0.08 for good matches.To analyze the performance of the framework,we tested our model in two Face antispoofing datasets named Replay attack datasets and CASIA-SURF datasets,which were used because they contain the videos of the subjects in each sample having three modalities(RGB,IR,Depth).The CASIA-SURF datasets showed an 89.9%Equal Error Rate,while the Replay Attack datasets showed a 92.1%Equal Error Rate.
基金Supported by the National Natural Science Foundation of China(NSFC,31472131/C170109,31201834/C170109)Scientific Research Foundation for Doctorship of Northeast Agricultural University(2010RCB37)
文摘Human depression patients often show abnormal pupillary reflex with morphological changes in hippo campus and prefrontal cortex.This study aimed to find the relationship between the prolonged pupillary light reflex(PLR) which had been shown by confined sows with chronic stress or depression and morphological changes in brain,in order to provide theoretical basis for that the confined environment should lead to sows' depression.A total of 637 sows of Durac,Landrace and Large White breeds with various parities were observed,and the pupil light reflex(PLR) was measured and the actual pupillary light reflex time(PLRT) were recorded.All the PLRTs were grouped based on the results of confidence interval:t>10%as group A,5%<t<10%as group B,1%<t<5%as group C and t<1%as group D.Three individuals were randomly selected from each group(12 sows in total) and the white tissues of hippocampus and the prefrontal cortex were prepared for HS staining slices(three slices/per tissue) for observation on tissue structure and pathological changes with high magnification(400X) of electronic microscope.The results showed that in group A(t>10%) pathological change was found in hippocampus,however,as PLRT increased from group B to group D,pathological changes in hippocampus tissues tended to be deteriorated with the increase of inflammatory cells and nuclear pyknosis phenomena.The same as those shown in hippocampus as the increasing of PLRT from groups A to D,more inflammatory cells appeared in prefrontal cortex for groups B and D.The results suggested that the tissue lesions of hippocampus and prefrontal cortex of the confined sows with prolonged PLRT might be the results of chronic stress or depression.
文摘建立了一种基于图像处理的快速瞳孔直径检测算法,运用此算法提取了反映阿片类药物成瘾人员与正常人对瞳孔光反射变化差异的3个特征值:绝对收缩幅度(absolute amplitude of contraction,AAC)、相对收缩幅度(relative amplitude of contraction,RAC)和收缩斜率(SCV,slope of contraction velocity);分别研究了成瘾、性别、近视、年龄、睡眠剥夺等因素对于这3个特征值的影响。不同性别、近视人员、睡眠剥夺人员与正常人之间的3个特征值均无显著差异,成瘾人员与之对比均显著减小。老年人相对于正常青年人,3个特征值都明显减小;与成瘾人员相比,仅在RAC值上有显著差异。结果表明,阿片类药物成瘾人员除了与正常人外,也与其他具有潜在影响瞳孔变化因素的非阿片成瘾人员在瞳孔对光反射的特征值上具有显著差异。该研究的实验数据为进一步建立基于检测瞳孔对光反射其直径发生变化的方法来快速、非接触地鉴别出阿片类药物成瘾人员提供了可靠的依据。
文摘It is well recognized that the direct pupillary light reflex(DPLR)and vision coexist. DPLR disappcars in eyes when they were blind due to diseases of the optic nerve or retina. I found that the reappearance of DPLR prior to the recovery of light pcrception in 21 eyes of 12 patients with no light perception caused by acute neuritis. It suggests that both the phenomenons are likely separated.
