Fingerprint enrollment using elongated fingerprint sensor

A method of enrolling a fingerprint of a user's finger having a longitudinal finger axis, by means of a fingerprint enrollment system comprising:

• an elongated fingerprint sensor for acquiring partial fingerprint images of said fingerprint, the fingerprint sensor having a sensing area being smaller than said fingerprint and having a longitudinal sensor axis;
• processing circuitry connected to said fingerprint sensor for forming a fingerprint enrollment representation for said finger based on a plurality of acquired partial fingerprint images;
• a memory;
• and
• a user communication interface for providing instructions to said user, said method comprising the steps of:
• instructing, through the user communication interface, the user to place said finger on the fingerprint sensor with a first finger orientation for achieving a first angle between said longitudinal finger axis and said longitudinal sensor axis;
• acquiring, using said fingerprint sensor, a partial fingerprint image for said first finger orientation;
• instructing, through the user communication interface, the user to place said finger on the fingerprint sensor with a second finger orientation for achieving a second angle, different from said first angle, between said longitudinal finger axis and said longitudinal sensor axis;
• acquiring, using said fingerprint sensor, a partial fingerprint image for said second finger orientation;
• forming, by said processing circuitry, the fingerprint enrollment representation for said finger based on the partial fingerprint images for said first and second finger orientations and a relation between said first angle and said second angle;
• and
• saving, by said processing circuitry, the fingerprint enrollment representation to said memory together with an identifier for said fingerprint to thereby enroll said fingerprint.