Method for obtaing optical projection parameter of camera

Abstract

The method for obtaining optical projection parameter of camera includes the following steps: utilizing the characteristics of scrambed image which has centrosymmetry, using a correcting article withseveral symmetrical and concentric geometrical figures to define the optical axis of camera lens, and further find out its projection centre point on the optical axis by using error testing method, at the same time solving its equivalent focusing and projection mode. Said invention is simple, can accurately define internal and external parameters of camera, so that it has extensive application range.

Description

technical field [0001] The present invention relates to a method for digital image processing and presentation, and in particular to a method for recovering distorted images by finding the optical projection parameters such as the projection center (viewpoint) and equivalent focal length (focal length) of the camera lens. Method for normal perspective images. Background technique [0002] Usually the general optical lens is used for imaging, and most of them hope that it conforms to the imaging result of linear projection. The image captured by the user under a similar lens will be very close to the real world, but it has a shortcoming—the angle of view is small, and the standard lens is used as the For example, the angle of view is about 45 degrees to 55 degrees. Therefore, in fields that require a large angle of view, such as monitors or endoscopes, wide-angle lenses or fisheye lenses are used instead, so that images with a large angle of view can be captured at one time. ...

AI Technical Summary

Problems solved by technology

[0002] Usually the general optical lens is used for imaging, and most of them hope that it conforms to the imaging result of linear projection. The image captured by the user under similar lens will be very close to the real world, but it has a shortcoming - the angle of view is small, and the standard lens is used as the For example, the angle of view is about 45 degrees to 55 degrees. Therefore, in fields that require a large angle of view, such as monitors or endoscopes, wide-angle lenses or fisheye lenses are used instead, so that images with a large angle of view can be captured at one time.

However, no matter which of the above-mentioned technical contents, they all use a fixed projection mode to correct the image, and have not exactly determined the parameters of the fisheye lens camera - the projection center (viewpoint) and the focal length (focal length). For the projection mode It is also assumed that Figure 1A and Figure 1B The projection mode described - "EquidistantProjection" - the most common projection mode for fisheye lenses

In the situation where the precise parameters are not determined and the projection mode is not clear, the original image can only be unfolded and restored, and the accuracy of the corrected image cannot be considered. The application in the field of stereoscopic image positioning is bound to be limited.

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