Now known map of a pixel grid column number, how to calculate the latitude and longitude coordinates, he webgis cartography development, Taiwan before and after interaction, the background and ranks number, front desk according to the longitude and latitude drawing,

CodePudding user response:

What the map coordinates to clear

CodePudding user response:

You speak a little bit map of tiles in pixel coordinates into the count of coordinate problem? Should be the first screen coordinates into Web Mercator coordinates, and then converted to latitude and longitude coordinates,

CodePudding user response:

Thank you, has been solved

CodePudding user response:

Consult your problem solved? I now also have known image tiles ranks number, want to according to the column number to calculate the specific latitude and longitude coordinates, also your advice please.

CodePudding user response:

reference 4 floor lovebabyhai response:

consult your problem solved? I now also have known image tiles ranks number, want to according to the column number to calculate the specific latitude and longitude coordinates, your advice please.

Later want to see, actually very simple, I the pixel grid column number is known, is 3600 * 1800, each with the longitude of the grid size 360/3600, latitude in 180/1800, you should be known after the projection of the cavalcade kilometer grid, should need projection transformation, the projection coordinate transformation for geographic coordinates, is need parameters,

CodePudding user response:

My image is not the world, is only a part of the Google the city image, now know only ranks number, want to work out concrete according to the column number of latitude and longitude coordinates

CodePudding user response:

refer to 6th floor lovebabyhai response:

my image is not the world, is just a part of the Google the city image, now know only ranks number, want to work out concrete according to the column number of latitude and longitude coordinates to

Right, that you can only in the case of map projection information known, the conversion of projection coordinates to geographic coordinates

CodePudding user response:

Images are projected, similar to Google images, if directly with the latitude and longitude, on average, in addition to, probably every case is not accurate, if is baidu, tencent maps these divisions, etc. They have their own level, as well as the selection of origin of coordinates, to consider

CodePudding user response:

What map projection have to know who you are