Restoration and recognition of distant, blurry irises.

Raw iris images collected outdoors at standoff distances exceeding 25 m are susceptible to noise and atmospheric blur and even under ideal imaging conditions are too degraded to carry out recognition with high accuracy. Traditionally, atmospherically distorted images have been corrected through the use of unique hardware components such as adaptive optics. Here we apply a pure digital image restoration approach to correct for optical aberrations. Image restoration was applied to both single images and image sequences. We propose both a single-frame denoising and deblurring approach, and a multiframe fusion and deblurring approach. To compare performance of the proposed methods, iris recognitions were carried out using the approach of Daugman. Hamming distances (HDs) of computed binary iris codes were measured before and after the restoration. We found the HD decreased from >0.46 prior to a mean value of <0.39 for random single images. The multiframe fusion approach produced the most robust restoration and achieved a mean HD for all subjects in our data set of 0.33 while known false matches remained at 0.44. These results show that, when used properly, image restoration approaches do significantly increase recognition performance for known true positives with low increase in false positive detections, and irises can be recognized in turbulent atmospheric conditions.

Facial distortion secondary to idiopathic gingival hyperplasia: surgical management and oral reconstruction with endosseous implants.

Little information exists regarding the surgical and oral reconstructive options for the patient with idiopathic gingival hyperplasia, especially with regard to endosseous implant placement and recurrence of the disease. The authors report a case of severe gingival enlargement and bone resorption involving the maxillary and mandibular arches in a 21-year-old female causing distortion of facial features. The etiology could not be established but the condition was exacerbated during pregnancy, causing chewing, speaking, and esthetic problems. The hyperplastic tissue and all the teeth were removed surgically, followed by immediate placement of 2 endosseous implants. Restoration of esthetics and function with a maxillary denture and mandibular overdenture were completed 3 months later. No disease recurrence was noted at the 6-month postoperative interval.