السلام علكيم ورحمة الله
ممكن احصل علي مساعدة في بعض الاشياء في هذا المشروع
اثناء درستي للمشروع لقيت بعض المشاكل في بعض الخطوات وهي
Fingerprint Image Segmentation
وهذا الشرح الذي وجده علي هذا الجزء
3.3 Fingerprint Image Segmentation
3.3 Fingerprint Image Segmentation
In general, only a Region of Interest (ROI) is useful to be recognized for each fingerprint image. The image area without effective ridges and furrows is first discarded since it only holds background information. Then the bound of the remaining effective area is sketched out since the minutia in the bound region are confusing with those spurious minutia that are generated when the ridges are out of the sensor.
To extract the ROI, a two-step method is used. The first step is block direction estimation and direction variety check [1], while the second is intrigued from some
Morphological methods.
1
. Block direction estimation
1.1 Estimate the block direction for each block of the fingerprint image with WxW in size(W is 16 pixels by default). The algorithm is:
I. Calculate the gradient values along x-direction (gx) and y-direction (gy) for each pixel of the block. Two Sobel filters are used to fulfill the task.
II. For each block, use Following formula to get the Least Square approximation of the block direction.
tg2ß = 2 å å (gx*gy)/å å (gx2-gy2) for all the pixels in each block.
The formula is easy to understand by regarding gradient values along x-direction and y-direction as cosine value and sine value. So the tangent value of the block direction is estimated nearly the same as the way illustrated by the following formula.
tg2q = 2sinq cosq /(cos2q -sin2q )
1.2 After finished with the estimation of each block direction, those blocks without significant information on ridges and furrows are discarded based on the following formulas:
E = {2 å å (gx*gy)+ å å (gx2-gy2)}/ W*W*å å (gx2+gy2)
For each block, if its certainty level E is below a threshold, then the block is regarded as a background block.
ROI extraction by Morphological operations
Two Morphological operations called ‘OPEN’ and ‘CLOSE’ are adopted. The ‘OPEN’ operation can expand images and remove peaks introduced by background noise
المشكلة هنا كيفة اقوم بوضع هذه المعادلة في برنامج الماتلاب لكي يكون الناتج كاالصوره الاتي ارجو ان اجد بعض المساعدة
