Determination of the orientation of the ridges of a fingerprint
AssigneeSTMicroelectronics S.r.l.
InventorChristel-Loic Tisse
Life of this patent
Estimating the term…
Abstract
A method and a circuit for determining the orientation of ridges of a digital image representing a fingerprint or the like, consisting for each image pixel of calculating a quantity taking into account the neighboring pixels in all directions, and of bidirectionally scanning the image line by line.
Claims9
A method for determining the orientation of ridges of a digital image (I) representing a fingerprint or the like, consisting for each image pixel of calculating a quantity taking into account the neighboring pixels in all directions, and consisting of bidirectionally scanning the image line by line.
A circuit (1) for temporarily storing blocks of a digital image (I), comprising:
- a matrix of V shift registers (Rj) of U words (Bij) to store an image block of U*V pixels;
- two shift registers (Vg, Vd) for loading in a first direction, said two registers being unloadable in parallel into the first (Blj), respectively last (BUj), words of all registers (Rj) in the matrix;
- and
- at least one shift register (H) for loading in the other direction, unloadable in parallel into all words (BiV) of the first (R1) or last (RV) matrix register, the different registers being interconnected to enable loading of the image by blocks in the first direction, in both directions, and in the second direction.
Dependencies are inferred from the claim text.