Space coordinate converting server and method thereof

A space coordinate converting method for a space coordinate converting server, comprising:

• receiving, by the space coordinate converting server, a field video from an image capturing device, wherein the field video is recorded with a 3D object, and the 3D object has a plurality of marked points;
• generating, by the space coordinate converting server, a point cloud model according to the field video, wherein the point cloud model comprises a plurality of points data;
• determining, by the space coordinate converting server, a plurality of key frames of the field video, wherein each of the plurality of key frames comprises a key image and a rotation and translation information of the image capturing device;
• mapping, by the space coordinate converting server, the plurality of points data of the point cloud model to the key image of each of the plurality of key frames based on the corresponding rotation and translation information of the image capturing device of each of the plurality of key frames for generating a 3D coordinate set corresponding to the key image of each of the plurality of key frames;
• determining, by the space coordinate converting server, a plurality of 2D coordinates of the 3D object in the key image of each of the plurality of key frames based on the plurality of marked points, wherein the plurality of 2D coordinates correspond to at least two marked points of the plurality of marked points;
• selecting, by the space coordinate converting server, a plurality of 3D coordinates from the 3D coordinate set according to the plurality of 2D coordinates, wherein the plurality of 3D coordinates correspond to the at least two marked points;
• and
• determining, by the space coordinate converting server, a space coordinate converting relation according to actual point coordinates of the at least two marked points and the plurality of 3D coordinates.