Abstract: A method for evaluating quality of image representing a fingerprint pattern is provided, the method including performing a filtering process on a region of the image including a digital filtering of the selected region successively performed a certain number of times. According to the method, convergence of said filtering process is determined, and the image within the region is classified as an image with identifiable pattern if the filtering process is convergent, whereas the image within the region is classified as an image with unidentifiable pattern if the filtering process is nonconvergent. The digital filtering is performed using a filter adapted to at least one of the following local image parameters: curvature of dermal ridges, scale and tilt angle of dermal ridges.

Abstract: The present invention relates to the digital processing of images, and, more particularly, to the digital filtering of fingerprint images. The present invention can be used in criminalistics for fingerprint identification. The object of the present invention is to develop a method for filtering a fingerprint image, that provides effective image processing in the areas where the curvature of fingerprint lines is high. This object is achieved by providing a method for filtering a fingerprint image, the method including the step of sequentially processing areas of the image by a directional filter having at least one central ridge and adapted to local properties of respective areas of the image, the local properties including distance between the ridges, orientation of the fingerprint line, and curvature of the same.

Abstract: The present invention relates to a method for forming a mark reference list using a database including a register of mark-forming objects in the form of a sample array, and a mark array. According to this method, a mark is compared with each sample of the sample array, match indexes of the mark and said each sample are determined based on said comparison, and a list of high match indexes of the mark and the samples is formed. The decision that a mark should be included into the reference list is made, if the match index of a query sample and the mark is higher than the lowest index of the list of high match indexes of the mark and the samples.

Abstract: The present invention relates to a method for forming a mark reference list using a database including a register of mark-forming objects in the form of a sample array, and a mark array. According to this method, a mark is compared with each sample of the sample array, match indexes of the mark and said each sample are determined based on said comparison, and a list of high match indexes of the mark and the samples is formed. The decision that a mark should be included into the reference list is made, if the match index of a query sample and the mark is higher than the lowest index of the list of high match indexes of the mark and the samples.

Abstract: A method for evaluating quality of image representing a fingerprint pattern is provided, the method including performing a filtering process on a region of the image including a digital filtering of the selected region successively performed a certain number of times. According to the method, convergence of said filtering process is determined, and the image within the region is classified as an image with identifiable pattern if the filtering process is convergent, whereas the image within the region is classified as an image with unidentifiable pattern if the filtering process is nonconvergent. The digital filtering is performed using a filter adapted to at least one of the following local image parameters: curvature of dermal ridges, scale and tilt angle of dermal ridges.

Abstract: The present invention relates to the digital processing of images, and, more particularly, to the digital filtering of fingerprint images. The present invention can be used in criminalistics for fingerprint identification. The object of the present invention is to develop a method for filtering a fingerprint image, that provides effective image processing in the areas where the curvature of fingerprint lines is high. This object is achieved by providing a method for filtering a fingerprint image, the method including the step of sequentially processing areas of the image by a directional filter having at least one central ridge and adapted to local properties of respective areas of the image, the local properties including distance between the ridges, orientation of the fingerprint line, and curvature of the same.