The design of an fast Fourier filter for enhancing diagnostically relevant structures - endodontic files.

Background: The endodontic working length is commonly determined by electronic apex locators and intraoral periapical radiographs. No algorithms for the automatic detection of endodontic files in dental radiographs have been described in the recent literature.

Method: Teeth from the mandibles of pig cadavers were accessed, and digital radiographs of these specimens were obtained using an optical bench.

An optimized video system for augmented reality in endodontics: a feasibility study.

Objectives: We propose an augmented reality system for the reliable detection of root canals in video sequences based on a k-nearest neighbor color classification and introduce a simple geometric criterion for teeth.

Material And Methods: The new software was implemented using C++, Qt, and the image processing library OpenCV. Teeth are detected in video images to restrict the segmentation of the root canal orifices by using a k-nearest neighbor algorithm.

Artefacts in CBCT: a review.

Artefacts are common in today's cone beam CT (CBCT). They are induced by discrepancies between the mathematical modelling and the actual physical imaging process. Since artefacts may interfere with the diagnostic process performed on CBCT data sets, every user should be aware of their presence.

Accurate registration of random radiographic projections based on three spherical references for the purpose of few-view 3D reconstruction.

Precise registration of radiographic projection images acquired in almost arbitrary geometries for the purpose of three-dimensional (3D) reconstruction is beset with difficulties. We modify and enhance a registration method [R. Schulze, D.

Determination of projection geometry from quantitative assessment of the distortion of spherical references in single-view projection radiography.

A method is introduced, inferring the three-dimensional (3-D) location from the 2-D radiographic shadow of an opaque spherical reference body of known radius by considering its elliptical distortion, the 2-D shadow location and a known source-to-receptor distance. Three noncollinear spheres fixed to a rigid object constitute all possible degrees of freedom, i.e.