| 摘要 |
<p>A fingerprint verification technique involves the derivation of data from a fingerprint in the form of an ordered set of values relating to the number of ridges (or troughs) measured orthogonal to a line across an area of the fingerprint, at each of a plurality of positions along the line. The data is derived using a semiconductor imaging sensor (18) consisting of a two-dimensional array of image sensing elements. Each line of the imaging sensor is read out as a varying DC voltage which is compared with a reference value in thresholding circuitry (42). The digital signal produced by the thresholding circuitry is used to clock a counter (44) to obtain for each row of the array a count of the ridges (or troughs) in that row of the array.</p> |
