A Novel Camera Calibration Method Based on Polar Coordinate

<div><p>A novel calibration method based on polar coordinate is proposed. The world coordinates are expressed in the form of polar coordinates, which are converted to world coordinates in the calibration process. In the beginning, the calibration points are obtained in polar coordinates. By transformation between polar coordinates and rectangular coordinates, the points turn into form of rectangular coordinates. Then, the points are matched with the corresponding image coordinates. At last, the parameters are obtained by objective function optimization. By the proposed method, the relationships between objects and cameras are expressed in polar coordinates easily. It is suitable for multi-camera calibration. Cameras can be calibrated with fewer points. The calibration images can be positioned according to the location of cameras. The experiment results demonstrate that the proposed method is an efficient calibration method. By the method, cameras are calibrated conveniently with high accuracy.</p></div

Multi-camera calibration board based on cameras’ positions.

<p>Multi-camera calibration board based on cameras’ positions.</p

Average of intrinsic parameters under different noise levels.

<p>Average of intrinsic parameters under different noise levels.</p

the standard deviations of <i>u</i>₀ with 3 and 10 pictures.

<p>the standard deviations of <i>u</i>₀ with 3 and 10 pictures.</p

Real Pictures—the accurate calibration board is at the top, the polar coordinates calibration board is at the bottom.

<p>Real Pictures—the accurate calibration board is at the top, the polar coordinates calibration board is at the bottom.</p

Standard deviations for parameters <i>α</i>,<i>β</i>,<i>γ</i>.

<p>Standard deviations for parameters <i>α</i>,<i>β</i>,<i>γ</i>.</p

Standard deviations for parameters <i>u</i>₀, <i>v</i>_0.

<p>Standard deviations for parameters <i>u</i>₀, <i>v</i>_0.</p

retrieval results based on Zhang’s method.

<p>retrieval results based on Zhang’s method.</p

retrieval results based on proposed method.

<p>retrieval results based on proposed method.</p