Mono-position calibration method can merely guarantee the accuracy for a camera with the area of well calibration

so multi-position calibration methods for intrinsic parameters digital camera is raised.In this method

the image surface is divided into several regions

the distribution and location of the camera is programmed

and all control points can be as sured to distributed on the whole image surface

so that the calibrated results can show the influences of distortion of the whole image surface.The calibration of multi-position can solve the problem of the points

whose accuracy vary irregularly

while exceeding the calibrating regions

when they are being calibrated by the position.The result of the experiment has proved that while measuring six positions on the standard rule with multi-position

the calculating results can remain stable to some extent

rather than showing too many errors on some parts.Therefore

the application of multi-erect position for calibration is effective to solve the problem of the irregular variation of the accuracy of the image formation.