Robotic C-arms are capable of complex orbits that can increase field of view, reduce artifacts, improve image quality, and/or reduce dose; however, it can be challenging to obtain accurate, reproducible geometric calibration required for image reconstruction for such complex orbits. This work presents a method for geometric calibration for an arbitrary source-detector orbit by registering 2D pr...

We describe a practical and precise calibration method for generating a top view image that is transformed so that a planar object such as the road can be observed from a direction perpendicular to its surface. The geometric relation between the input and output images is described by a 3× 3 homography matrix. Conventional methods use large planar calibration patterns to achieve precise transfo...

The use of the recovery term has presented some confusion in Analytical Chemistry. Recent IUPAC recommendations propose to distinguish between two terms: recovery or recovery factor, Re, and apparent recovery, Re*. Apparent recovery includes recovery factor and a new recovery term proposed in this paper, named calibration recovery, Re(C), which depends of the type of systematic error due to the...

In this paper, we present a hybrid method for calibration of an endoscope and its registration with an active optical tracker. Practically, both operations are done simultaneously by moving an active optical marker in the field of view of the two devices. By segmenting image data, the LEDs composing the marker are extracted and the transformation matrix between the two referentials (homography)...

An improved inertial and visual sensors calibration method is proposed in this paper, which is the method of fractional step to calibrate between inertial and visual sensors. The relationship of the rotation between inertial and vision sensors can be obtain by solving the improvement of hand-eye calibration equations. The inclinometer sensor is introduced in the process of calibration and the o...

Objective: In view of contemporary panoramic camera-laser scanner system, the accuracy of traditional calibration method based on the target feature is not stable and multiple calibrations are needed. The method based on statistical optimization has the disadvantage that the requirement of the number of laser scanner’s channels is relatively high. Calibration equipments with extreme accuracy fo...

Recently, some spaceborne polarimetric synthetic aperture radars, such as TerraSAR X (Xband), RADARSAR-2 (C-band) and PALSAR (L-band), are available to measure a scattering matrix of terrain and polarimetric data analysis techniques are being developed for terrain classification, forest biomass and soil moisture estimations, etc. Thus polarimetric calibration is necessary to obtain the accurate...

The RGB signals generated by different cameras are not equal for the same scene. Therefore, cameras are characterized based on a CIE standard colorimetric observer. One method of deriving a colorimetric characterization matrix between camera RGB output signals and CIE XYZ tristimulus values is least squares polynomial modeling. Yet, this involves tedious experiments to obtain a camera transfer ...

Item replenishment is important to maintaining a large scale item bank. In this paper we consider calibrating new items based on pre-calibrated operational items under the DINA model, the specification of which includes the so-called Q-matrix, as well as the slipping and guessing parameters. Making use of the maximum likelihood and Bayesian estimators for the latent knowledge states, we propose...

The Jaccard index is a standard statistics for comparing the pairwise similarity between data samples. This paper investigates the problem of estimating a Jaccard index matrix when there are missing observations in data samples. Starting from a Jaccard index matrix approximated from the incomplete data, our method calibrates the matrix to meet the requirement of positive semi-definiteness and o...