Abstract: A method for combining two templates. A first template having a first minutia set and a second template having a second minutia set are provided. The first template is compared with the second template to obtain a matching minutia set. Registration parameters are calculated from the matching minutia set. The registration parameters can be referenced to either the first minutia set or the second minutia set. All minutiae in the first or the second minutia set are translated to be on the same coordinate system as the other minutia set. The minutia sets are then combined to construct a combined minutia set. In one embodiment, an overlap region is drawn for the first template and the second template, the overlap region containing at least minutiae from the matching minutia set.

Abstract: The present invention relates to a fingerprint sensing device comprising a planar array of closely-spaced capacitive sense elements. When a finger is placed in close proximity to the sensing device, the capacitive sense elements measure a capacitance between the finger and a single capacitor plate in each sense element. This is accomplished by precharging each capacitor plate, and then using a known current source to remove a fixed amount of charge from each capacitor plate. The measured capacitance varies as a function of the distance between the capacitor plate and the finger surface. Thus, a capacitance measurement allows the distance between the capacitor plate and the finger surface to be determined. Distance measurements across the array of sense elements are combined to produce a representation of the pattern of ridges on the finger surface which comprise a fingerprint.

Abstract: A method of operating a personal verification system includes acquiring with a sensor a first image of a first biometric feature, removing background noise associated with the sensor from the image, and storing at least a portion of the first image. The method also includes acquiring with the sensor a second image of a second biometric feature and comparing at least a portion of the second image with the first image. If the second image is substantially different from the first image, the second image is displayed.

Abstract: An automatic gain amplifier is disclosed that dynamically improves the quality of scanned biometric information. According to one embodiment, an image distribution of the scanned biometric is generated. Next, areas of higher image distribution are identified. An iterative process of adjusting the gain of, for instance, a capacitive sensing, is employed until an optimum separation of the areas of higher image distribution is achieved. Once the optimum separation is achieved, the gain is applied to the biometric sensing device so that biometric information can be scanned with improved image clarity. Electronic circuitry and software for implementing the methods are disclosed.

Abstract: A system and method for automatically determining a set of default settings (with respect to a blank image) so that a uniform and high contrast image results when, for example, a finger is present on a sensor device. A background noise image and other diagnostic data, such as non-functional areas, are also automatically determined with respect to the blank image and stored for future reference. The above processing is performed each time the sensor device is initialized. Once the initialization process is complete, the individual places the required biometric feature, for example, a finger on the sensor device. The methodology adjusts the set of default settings to account for the condition of the biometric feature being imaged by increasing or decreasing the sensitivity level of the sensor device. The determination of optimum sets is achieved by analyzing specific regions of the image data rather than the entire image.

Abstract: The present invention relates to a fingerprint sensing device comprising a planar array of closely-spaced capacitive sense elements. When a finger is placed in close proximity to the sensing device, the capacitive sense elements measure a capacitance between the finger and a single capacitor plate in each sense element. This is accomplished by precharging each capacitor plate, and then using a known current source to remove a fixed amount of charge from each capacitor plate. The measured capacitance varies as a function of the distance between the capacitor plate and the finger surface. Thus, a capacitance measurement allows the distance between the capacitor plate and the finger surface to be determined. Distance measurements across the array of sense elements are combined to produce a representation of the pattern of ridges on the finger surface which comprise a fingerprint.

Abstract: An apparatus for detecting topographic variations on an object such as a finger includes an array of sensing elements disposed on a substrate which each have a parasitic capacitance. An insulating receiving surface is disposed over the array of sensing elements and is adapted to receive the object such that a sensing element and a portion of the object located thereabove creates a measurable change in capacitance with respect to the parasitic capacitance. An electronic circuit is coupled to the array of sensing elements for measuring the measurable change in capacitance.

Abstract: The present invention makes it possible for a user to have a security key created from one or more biometric elements of the user, such as a fingerprint. For example, a biometric feature or combination of biometric features of the user can be used to create an instance of a problem which can only be solved by data inherent in the biometric feature or combination of biometric features. The user can supply the data to solve the problem by inputting, through an appropriate input device, an image, or other representation of the biometric elements from which the data that will solve the instance of the problem is derived. If problem is solved, either completely or partially, using the derived data then the identity of the user can either be verified or ascertained. the solution can then be used for other purposes such as the generation of a cryptographic key.