106,619 research outputs found

    Comparing landmarking methods for face recognition

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    Good registration (alignment to a reference) is essential for accurate face recognition. We use the locations of facial features (eyes, nose, mouth, etc) as landmarks for registration. Two landmarking methods are explored and compared: (1) the Most Likely-Landmark Locator (MLLL), based on maximizing the likelihood ratio [1], and (2) Viola-Jones detection [2]. Further, a landmark-correction method based on projection into a subspace is introduced. Both landmarking methods have been trained on the landmarked images in the BioID database [3]. The MLLL has been trained for locating 17 landmarks and the Viola-Jones method for 5 landmarks. The localization error and effects on the equal-error rate (EER) have been measured. In these experiments ground- truth data has been used as a reference. The results are described as follows:\ud 1. The localization errors obtained on the FRGC database are 4.2, 8.6 and 4.6 pixels for the Viola-Jones, the MLLL, and the MLLL after landmark correction, respectively. The inter-eye distance of the reference face is 100 pixels. The MLLL with landmark correction scores best in the verification experiment.\ud 2. Using more landmarks decreases the average localization error and the EER

    Defect detection in textile fabric images using subband domain subspace analysis

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    In this work, a new model that combines the concepts of wavelet transformation and subspace analysis tools, like Independent Component Analysis, Topographic Independent Component Analysis, and Independent Subspace Analysis, is developed for the purpose of defect detection in textile images. In previous works, it has been shown that reduction of the textural components of the textile image by preprocessing has increased the performance of the system. Based on this observation, in present work, the aforementioned subspace analysis tools are aimed to be applied on the sub-band images. The feature vector of a sub-window of a test image is compared with that of the defect-free image in order to make a decision. This decision is based on a Euclidean distance classifier. The performance increase that results using wavelet transformation prior to subspace analysis has been discussed in detail. While all the subspace analysis methods has been found to lead to the same detection performances, as a further step, independent subspace analysis is used to classify the detected defects according to their directionalities

    Research on the Covering of the Biomimetic Pattern Recognition of the High Dimensional Information Geometry

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    Objective: To research on the application of high dimensional space theory to the biomimetic pattern recognition. Procedures: The sample was constructed into a k-dimensional simplex in a high dimensional space and 0.85 times of the average distance between the vertices was chosen as the threshold value thus a convex cell body covering the k-dimensional simplex was constructed. By determining whether the sample point could be covered by the convex cell body derived from a certain sample group, the sample was recognized and classified. Methods: The orthogonal complementary space of the subspace was constructed and the Euclidean distance between the point and the subspace was calculated and the distance from the point to the k-dimensional simplex was further calculated. Results: The study solved the problem of whether the sample point is covered by a certain convex cell body and its correctness was testified via human-face recognition
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