Iso 9001: 2008 Certified Journal, Volume 4, Issue 7, July 2014
International Journal of Emerging Technology and Advanced Engineering
Download 0.9 Mb. Pdf ko'rish
|
IJETAE 0714 149
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com ( ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 7, July 2014) 960 III. P RESENT S CHEME A state of art iris recognition system comprises the following four basic modules:- Image acquisition Iris segmentation Normalization and iris code generation Comparison and recognition A typical iris segmentation process includes the following steps: demarcating the iris inner and outer boundaries at the pupil and sclera; demarcating its upper and lower eyelids if they occlude; and detecting and excluding any superimposed occlusions such as a eyelash, eyelids, shadows, or reflections. We have presented a method which takes less time for segmentation and finds accurate circles for pupil and iris. This technique uses median filters to enhance the image before segmentation. Thus segmentation is applied which divides the image into a number of clusters only, in which iris region belongs to single cluster only. After that edge detection has been carried out in order to find better edges needed in hough transform for finding iris circle. Below is the proposed algorithm in this work. Step I- Preprocess the input image in order to extract eye region from the input image. Filters and extract eye region from the input image. Filters and extract eye region from the input image. Filter and contrast adjustment functions are used in this step to better highlight eye region. Step II- Smoothing filters have been applied on the extracted eye portion in order to get better results in image segmentation. Step III- Segmentation has been done for the extracted portion using fuzzy means clustering and iris region has been located in a cluster. Step IV- Edge detection has been applied on the segmented image. We tried different filters like Sobel, Prewitt, Canny but Canny gave better results in edge detection. Step V- Circular Hough transform has been applied in order to get iris and pupil area from the image. Step VI- Inner o0f the pupil area has been excluded from the image as it is not a biometric tool and iris region has been kept as original. Step VII- Upper and lower eyelids have been removed which results in required iris neede for matching. Step VIII- Upper and lower eyelids have been removed which results in required iris needed for matching. Step IX- Finally template has been generated and has been matched to the existed database. V. E XPERIMENTAL R ESULTS The software implementation of the project has been done using MATLAB. MATLAB stands for MATRIX LABORATORY, software developed by Mathsworks honor in USA. Procedure of the proposed algorithm has been explained as below: It comprises of few basic modules: Image Preprocessing, Phase -1 Iris Localization, Phase-2 Iris Localization, and Fitting Non-circular Contours. Literature reveals that circular hough transform(CHT) is tolerant to broken contours of the objects in the ideal images. However It may not be true for the non ideal data. It may be because of the non uniform illumination, non circular iris contours and occlusions such a hair, glasses, contact lens, eyelids and eyelashes. However to make CHT robust for the non ideal data as well, we augment it by the image gray level, statistics for example, global average gray level intensity, lower and upper saturated gray level limits of the eye image. This combination of CHT and gray level statistics of image results in a better strategy for finding iris. It implies that a circular region in an eye image would be considered as an iris/pupil region, provided the following two conditions are true: A peak corresponding to the pupil/iris circle should be present in CHT accumulator; and Gray level intensity of that circular region should be relatively low with respect to some threshold value. Next, module localizes the pupil and iris circles in the preprocessed eye image using an effective scheme. As we mentioned earlier, our focus is on precise localization of the iris inner and outer contours, therefore the final localized iris may contain eyelid and eyelashes occlusions as in. |
Ma'lumotlar bazasi mualliflik huquqi bilan himoyalangan ©fayllar.org 2024
ma'muriyatiga murojaat qiling
ma'muriyatiga murojaat qiling