This cylindrical imaging equation can not only be used for panoramic stitching, but also be used for precision analysis, test results show: ①this method can be used for panoramic stitching under the condition of multi-camera and incline imaging ②the accuracy of panoramic stitching is affected by 3 kinds of parameter errors including focus, displacement and rotation angle, in which focus error can be corrected by image resampling, displacement error is closely related to object distance and rotation angle error is affected mainly by the number of cameras. This paper proposes a new method for cylindrical panoramic image mosaic, which set the number of mosaic camera, imaging focal length, imaging position and imaging attitude, simulate the mapping process of multi-camera and construct cylindrical imaging equation from 3D points to 2D image based on photogrammetric collinearity equations. With the rise of virtual reality (VR) technology, panoramic images are used more widely, which obtained by multi-camera stitching and take advantage of homography matrix and image transformation, however, this method will destroy the collinear condition, make it's difficult to 3D reconstruction and other work. After that, we inferred accessibility rules. Similar to extracting geomorphic traits from contour lines, we found accessibility rules by analyzing the arrangement form, density, bending form, bending direction and stretching direction of isochrones which was generated by the above approach. This advantage made it convenient to generate real-time isochrones. Since the algorithm was based on field theory, we could flexibly load space constraints for any part of interested zones. Then we used the extending convex hull and angle bisector displacement to generate isochrones. Accessibility expansion paths were obtained on the basis of the network rasterization model, considering unique constraints of isochrones extension, such as road conditions, moving criteria and time sections. We proposed the flow method to generate isochrones, which was analogous to the process of water drop spreading along the wood texture. This article systematically studied the definition, characteristics and generation methods of isochrones. Accessibility rules can be found through analyzing the morphological features of isochrones. Features of road network and traffic conditions should be considered when generating isochrones. An isochrone is a visual representation of time accessibility which refers to a particular point in the road network.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |