Specifically, the application of AIPF on [theta] direction carries out within an integration rectangle with wxh dimensions, it extends along a central line irradiated from the image center and having [theta] with x-axis.
Accordingly, considering the approximate iris center detected in the previous section as the image center, AIPF can be applied to find a set of radial boundary points.
This is accomplished by computing the gradient of the projection curve resulted by each application of AIPF.
Here, it must be mentioned that this database has been manually edited  but it does not effect the application of AIPF to detect iris' edge points since editing was limited to the pupil region.
The experiments were done under the condition that the same initial estimate of iris center is provided for both AIPF and Daugman methods.