| 摘要 |
A method for determining the position of a client device is disclosed herein. The client device comprises a display screen and a front-facing camera for capturing images of objects which the display screen faces. The method comprises the steps of: determining a first estimate of the position of the client device 100 using positioning signals; using the front-facing camera to capture an image 200; acquiring object-shape data 400 representative of the shape of objects within an area, wherein the first estimate of the position of the client device is within the area; comparing the image with the object-shape data 500 to establish a match associated with a second estimate of the position of the client device ; and outputting a position 600 for the client device based on the second estimate. Processing the image can involve identifying parts of the image that are sky and non-sky, and enhancing the distinction between the sky and non-sky. The non-sky part can further be identified as a non-building object, excluded from any comparison, and replaced by either sky or building based on a prediction of what lies behind the non-building object. |
