This paper evaluates feature extraction techniques in aspect of watermark synchronization. Most watermarking algorithms suffer from geometric distortion attacks that desynchronize the location of the inserted watermark. The process of synchronizing the location for watermark insertion and detection is crucial to design robust watermarking. One solution for watermark synchronization is to use fe...

BACKGROUND Flexible video bronchoscopes, in particular the Olympus BF Type 3C160, are commonly used in pediatric respiratory medicine. There is no data on the magnification and distortion effects of these bronchoscopes yet important clinical decisions are made from the images. The aim of this study was to systematically describe the magnification and distortion of flexible bronchoscope images t...

The star tracker is a prerequisite device to realize high-precision attitude determination for spacecraft. However, due the errors in optical lens machining, path assembly, and temperature alternation, instruments suffer from some amount of geometric distortion, resulting declining accuracy. on-orbit distortion correction images indispensable precise performance. In this paper, novel single-lay...

in this paper, two new quadrilateral elements are formulated to solve plane problems. low sensitivity to geometric distortion, no parasitic shear error, rotational invariance, and satisfying the felippa pure bending test are characteristics of these suggested elements. one proposed element is formulated by establishing equilibrium equations for the second-order strain field. the other suggested...

In this paper, we present a new model to measure the contour point distortion for the vertex-based shape coding with B-splines, called accurate distortion measurement using analytical model (ADMAM). Different from existing distortion measurements containing approximation, quantization or parameterization process, our distortion is defined on the original B-spline. It is modeled as the shortest ...

A novel algorithm for uncalibrated stereo imagepair rectification under the constraint of geometric distortion, called USR-CGD, is presented in this work. Although it is straightforward to define a rectifying transformation (or homography) given the epipolar geometry, many existing algorithms have unwanted geometric distortions as a side effect. To obtain rectified images with reduced geometric...