| 摘要 |
PROBLEM TO BE SOLVED: To provide a correction method of lens distortion with which a distortion coefficient is estimated in a short time and further with high accuracy and a correction image can be accurately generated.SOLUTION: In a correction method of lens distortion, attention is paid to a character that a relationship between a temporary distortion coefficient and an error is represented by a single-peak target function and a distortion coefficient can be estimated from only one minimal point of the error. A frame line after correction is determined by using the temporary distortion coefficient and a regression line is computed from the frame line after the correction. An error between coordinates of the frame line after the correction and the regression line is computed and a temporary distortion coefficient calculating a minimum error is estimated as a distortion coefficient but magnitude of errors of two temporary distortion coefficients are compared. One of the temporary distortion coefficients is updated to a predetermined error threshold value on the basis of the magnitude and a range of temporary distortion coefficients is narrowed down. Then, a repetitive value is added to a lower limit of the temporary distortion coefficient successively up to an upper limit within the narrowed range, and an error of each added temporary distortion coefficient is calculated. Then, a temporary distortion coefficient calculating a minimum error is estimated as a distortion coefficient. |
