The present invention provides an iris
preprocessing algorithm based on space distance circle marking
edge detection. The method comprises a first step of performing
image acquisition on an iris of a
human eye through a photographing device, thus to obtain an original
gray level image; a second step of carrying out
noise processing on the acquired image by using a median filtering
algorithm; a third step of decomposing the
iris image into four subband images by utilizing Haar wavelets; a fourth step of carrying out
edge detection on an inner edge of the iris by using Canny operators; a fifth step of carrying out precision positioning of an inner circuit of the iris by using a sub pixel circle positioning
algorithm; and a sixth step of carrying out accurate positioning on an outer circuit by using a method of increasing searching
radius step length. According to the iris
preprocessing algorithm based on the space distance circle marking
edge detection, the Canny operators are utilized for filtering, enhancement and detection, the sub pixel circle positioning
algorithm is utilized for carrying out accurate positioning of the inner circle of the iris, and the efficiency of circle detection operators is promoted by using the method of increasing the searching
radius step length, thereby realizing accurate positioning of the outer circle of the iris, raising the detection precision, and promoting the detection speed.