Retrieve bounding box from a Google Satellite Photo

Question

I have a bunch of satellite photos downloaded from Google Maps by a third party. The data looks like down below, where each row is a photo. I also have the resolution of each pic.

photo_id	zoom	center_lat	center_lon
1	20	48.871998764001	8.642190889688
2	18	49.4295354	10.9601192
3	18	49.4295354	10.9601192
4	18	58.426932941296	22.657546623349

I wonder if - with this data - I can retrieve the bounding box of each photo -- which I need to retrieve OpenStreetMaps data of the buildings in each picture.

Can I use the center coordinates and the zoom level to retrieve an approximate bounding box?

Answer 1

To get the bounding box, you need to obtain the coordinates of left/right, bottom/top limits.

Google Map uses the Mercator projection, so you need to find the coordinates in this system with a unit of meter first. https://en.wikipedia.org/wiki/Web_Mercator_projection

To do so, I suggest you can try to convert the existing center location to this projection first. Next, you can use the zoom level to calculate the pixel resolution, i.e., how many meters does one pixel represent. Some example is here: http://idlcoyote.com/idldoc/cg/cggoogle_metersperpixel.html

Once you have the above information, you can calculate the bounding box coordinates in meters using the image size, pixel resolution, and center location.

Last, you can convert the coordinates back to lat/lon-based WGS 84 system.