calculate the distance between the place where I am taking photo and the object I am taking

I can get the latitude and longitude where I am taking phot开发者_如何学Co. I can also get the Exif information of the photo I took.

I want to know how can I calculate the distance between the place I am taking photo and the object I am taking by above informations?

give me some constructive opinions. thanks very much.

You may get lucky with the SubjectDistance exif tag. Note that not all cameras set this tag.