A distance measurement method available to texture surface by using complex-log mapping

In this paper, the authors propose a method to measure the distance from a camera to an object´s surface with arbitrary texture pattern. The method uses two images which are taken at two camera positions while moving the camera along its optical axis. The distance between the two camera positions is assumed to be known. The distance from the camera to the object is computed by calculating the ratio between the size of the object projected on the two images. To calculate the ratio, complex-log mapping is applied according to the fact that the two images have concentric circles features