Patent ID: 7970185

Claim:
A method of capturing a fingerprint, comprising: obtaining a first fingerprint image in a guard region preset within a captured image, the guard region including less than all of the captured image; and extracting a fingerprint region based on a predicted color distribution, the predicted color information based on color information associated with the first fingerprint image, the extracted fingerprint region including the first fingerprint image within the guard region and at least a portion of the fingerprint region extending beyond the guard region within the captured image, wherein the extracting of the fingerprint region includes expanding the fingerprint region based on the predicted color distribution, and wherein extracting of the fingerprint region includes: extracting color information for each pixel of the first fingerprint image; transforming the color information into normalized color coordinates; calculating a mean vector and a covariance matrix of the first fingerprint image based on the normalized color coordinates; setting as target pixels, pixels which are not yet determined to be associated with one of a fingerprint region or a background region, within the captured image outside of the guard region; extracting target color information of the target pixels and transforming the target color information into target normalized color coordinates; calculating a distance indicating a similarity between the first fingerprint image and the target pixels based the target normalized color coordinates of the target pixels, the mean vector and the covariance matrix: comparing the calculated distance with a distance threshold; and expanding a temporary fingerprint region according based on a result of the comparison.