A Quaternionic Wavelet Transform-based Approach for Object Recognition

Recognizing the objects in complex natural scenes is the challenging task as the object may be occluded, may vary in shape, position and in size. In this paper a method to recognize objects from different categories of images using quaternionic wavelet transform (QWT) is presented. This transform separates the information contained in the image better than a traditional Discrete wavelet transform and provides a multiscale image analysis whose coefficients are 2D analytic, with one near-shift invariant magnitude and three phases. The two phases encode local image shifts and the third one contains texture information. In the domain of object recognition, it is often to classify objects from images that make only limited part of the image. Hence to identify local features and certain region of images, patches are extracted over the interest points detected from the original image using Wavelet based interest point detector. Here QWT magnitude and phase features are computed for every patch. Then these features are trained, tested and classified using SVM classifier in order to have supervised learning model. In order to compare the performance of local feature with global feature, the transform is applied to the entire image and the global features are derived. The performance of QWT is compared with discrete wavelet transform (DWT) and dual tree discrete wavelet transform (DTDWT). Observations revealed that QWT outperforms the DWT and shift invariant DTDWT with lesser equal error rate. The experimental evaluation is done using the complex Graz databases.Defence Science Journal, Vol. 64, No. 4, July 2014, pp. 350-357, DOI:http://dx.doi.org/10.14429/dsj.64.450

Augmentation of interdental papilla with platelet-rich fibrin

Background: Dental esthetics has become a great concern for both dental practitioners and patients in addition to maintaining oral health. The presence of interproximal papillae between the maxillary anterior teeth is a key esthetic component. Recession of interdental papilla leads to various functional problems such as food impaction, phonetics and esthetic problems such as the formation of black triangle which poses a great challenge. Aim: This study aims to evaluate the augmentation of interdental papilla with platelet-rich fibrin. Materials and Methods: A total of 25 sites from systemically healthy individuals with papillary recession (Nordland and Tarnow class 1 and 2) were recruited in the study. Han and Takei procedure was planned and augmentation was done with platelet-rich fibrin. Various parameters such as distance from the tip of the contact point to the gingival margin, width of the keratinized gingiva, and Jemt score were measured at baseline, 3 and 6 months postoperatively. Healing index was measured at the 1st, 2nd, and 3rd week postoperatively. Results: Data collected were statistically analyzed. Mean value of distance from the contact point to the gingival margin was 4.38 mm at baseline and at 6-month postoperatively, it reduced to 0.36 mm. There was an increase in width of the keratinized gingiva which was clinically and statistically significant. Other parameters such as healing index, Jemt score, and visual analog scale (aesthetics) were also statistically significant postoperatively