The Research Of Feature Extraction Based On Palmprint Image

The main purpose of this dissertation is to discuss palmprint. By studying the line extraction and selection method from palmprint, this dissertation analyzes the techniques of feature extraction , image segmentation with low contrast and heavy noisy background .Since palmprint has the stablity and uniqueness as fingerprint, the personal authentication can be determined completely by the line, geometry, minute.and texture features. Line features obtained from the lower resolution images has manv advantages compared with fingerprint and have become the most important character for palmprint identification. Line patterns in palmprint are very complicated because of the low contrast and the heavy noise caused by fine wrinkles and ridges, so it is a challenging task to complete the feature extraction. On the basis of morphological pyramind and morphological wavelet, a series of feasible and effective approaches to palmprint analysis have been developed .this dissertation mainly studies the approaches for palmprint identification in the following aspects: [1] Alignment and normalization online palmprint images.The contour lines and the key points for the alignment are extracted out by gray morphological grads and by coner detection method respectively. By these keypoints, we can establish a coordinate for the normalization. [2] Extraction line features from offline palmprintA line extraction algorithm based on morphological median pyramid and Law's template is proposed for offline palmprint. By this nonlinear multi-resolution analysis, line features can be effectively extracted out and noise can be effectively restrained. [3] Extraction line features from online palmprint.Stable, simple line features of online palmprint are the key issues for popularization the palmprint identification technology. A line extraction method based on morphological wavelet and spatial directionalselection template is proposed for online palmprint, by which lines can beeffectively extracted out.Feature extraction is a important part of Palmprint identification. The methods used for palmprint analysis can be easily extended to other recognition fields. Palmprint analysis is an interesting and important research field with theoretic and practical meaning. More attention has been paid on the key techniques such as extraction line features , Selection line features and classiflcationl ,which are very important to image analysis and pattern recognttion and helpful to generalize this technology into practice.