Model Image Distortion

Design, Construction and Evaluation of an Anthropomorphic Head Phantom for Assessment of Image Distortion in Stereotactic Radiosurgery Planning Systems

Introduction: In recent years, the use of magnetic resonance (MR) images in radiation treatment planning has drawn considerable attention. However, although the extent of a tumor can be determined in great detail on MR images, the geometric accuracy of these images is limited by distortions stemming from the inhomogeneity of the static background magnetic field, the nonlineari...

A Novel Method for Measuring, Regardless of Image Distortion and Lens Varying Specifications in Endoscopic Treatment of Vesicoureteral Reflux

Effect of Phase-Encoding Reduction on Geometric Distortion and BOLD Signal Changes in fMRI

Introduction Echo-planar imaging (EPI) is a group of fast data acquisition methods commonly used in fMRI studies. It acquires multiple image lines in k-space after a single excitation, which leads to a very short scan time. A well-known problem with EPI is that it is more sensitive to distortions due to the used encoding scheme. Source of distortion is inhomogeneity in the static B0 field that ...

Single Image Dehazing Algorithm Based on Dark Channel Prior and Inverse Image

The sky regions of foggy image processed by all the existing conventional dehazing methods are degraded by color distortion and severe noise. This paper proposes an improved algorithm which combines dark channel prior and inverse image. We first invert the foggy image, and then estimate the transmission of the inverse image. At last, compared with the non-inversed transmission, the larger value...

Experiment on Parameter Selection of Image Distortion Model

Most of current camera calibration methods for a non-metric digital camera adopt polynomials of image coordinates composed of terms representing the correction to the principal distance, the offsets of the principal point, the radial lens distortion, and the decentering lens distortion of the target camera as the image distortion model. However, there is no standard procedure to evaluate approp...

Lens Distortion Rectification Using Triangulation Based Interpolation

Nonlinear lens distortion rectification is a common first step in image processing applications where the assumption of a linear camera model is essential. For rectifying the lens distortion, forward distortion model needs to be known. However, many self-calibration methods estimate the inverse distortion model. In the literature, the inverse of the estimated model is approximated for image rec...