Claims
- 1. A method for determining a distance between features of a fingerprint, comprising the steps of:a. determining a path between the features; b. segmenting the path into one or more segments, each segment having a center; c. selecting a segment; d. determining if the segment is any one of the following: a valley segment and a ridge segment; e. if the segment is a valley segment, determining a width of the valley; and f. if the segment is a ridge segment, incrementing the distance only if the determined width of the valley is greater than a minimum width.
- 2. A method for determining a ridge count between two minutiae in an image of a fingerprint, comprising the steps of:segmenting a path between the two minutiae into segments, each segment having a center, where the path has a width a N pixels, where N is greater than two, and where each segment is comprised of the N pixels that are disposed on a line that crosses the path; for each segment in turn, determining if at least one of the N pixels that comprise the segment indicate the presence of a ridge; if the presence of a ridge is indicated, incrementing a ridge count only if the method is in a receptive state, and then placing the process into a nonreceptive state; and if the presence of a ridge is not indicated, assuming that the segment is a valley segment and, after M successive valley segments are indicated, placing the process into the receptive state.
- 3. A method as in claim 2, wherein M has a value in the range of about two to about four.
- 4. A method as in claim 2, wherein N has a value in the range of about three to about five.
- 5. A method as in claim 2, wherein N and M are both equal to three.
- 6. A method as in claim 2, and further comprising a step of terminating the counting of ridges between the two minutiae if a segment is found to contain an invalid pixel.
- 7. A method as in claim 2, wherein the segment centers between two successive segments are located one pixel apart.
Parent Case Info
The present application is a continuation of 08/837,069 filed Apr. 11, 1997 and claims priority to co-pending U.S. provisional application 60/032,713 filed Dec. 13, 1996.
US Referenced Citations (11)
Non-Patent Literature Citations (2)
Entry |
T. Ruggles et al., “Automated Fingerprint Identification Systems, I. North American Morpho System”, Advances in Fingerprint Technology, pp. 212-226, CRC Press, Inc., 1994. |
N.K. Ratha et al., “Adaptive Flow Orientation-Based Feature Extraction in Fingerprint Images”, Pattern Recognition, vol. 28, No. 11, pp. 1657-1672, 1995. |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/032713 |
Dec 1996 |
US |
Continuations (1)
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Number |
Date |
Country |
Parent |
08/837069 |
Apr 1997 |
US |
Child |
09/302109 |
|
US |