tile size other than 256 using url with center lat/long

[msteiger]

tile size other than 256 using url with center lat/long

[msteiger]

Hello Lionel,
I do not know how google maps provides the tiles. Are you sure they are provided as 512px images?

In any case, why would you want that? Is there an advantage of using bigger tiles?

[lionelmazeyrat]

Hello Martin,
you can get googlemaps tiles with :
https://maps.googleapis.com/maps/api/staticmap&center=[LAT],[LONG]&key=[MY_KEY]&maptype=roadmap&size=256x256
Free key can be obtained at :
https://developers.google.com/maps/documentation/static-maps/?hl=de
It works well with the getTileUrl function posted above.

But with size=512x512, it doesn't works, tiles displayed are not correct.

I need to use 512x512 (or 640x640) which are the large dimension provided by google for free.

On each tile google add a watermark on the bootom, so with larger tiles this watermark is less annoying for example if the map size if around 4 tiles.

[msteiger]

I can reproduce the problem. See the linked commit above. It looks like the tile rendering is correct.

The displayed images have overlapping content, so it's probably the computation of lat/lon values from the X and Y values that isn't correct for other tile sizes. Where did you get the formulas from?

[lionelmazeyrat]

I found the formula here :
https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#Tile_bounding_box
See Python - Tile numbers to lon./lat.

[lionelmazeyrat]

Hello martin, have you found some times to add support for tiles largest than 256px ???
It will be very interesting to support lots of tiles prividers with request with center lat/long (google, tomtom, herewego, mapquest,....)

[msteiger]

I investigated a little and could not find any obvious error. If you have the time, it would be great if you could have a look yourself and open a PR for it.

[lionelmazeyrat]

Thanks, I did not found where the tile size was involved or any obvious error...

[msteiger]

I found the error ... and more ... the Google Maps API aims at providing one single tile that covers the entire viewport. It therefore cuts off small bits of text reaching into the visible area. As a result the tiles are not really ... well .. tiling.

Is there anything OpenStreetMap does not cover? If so, you might want to try Nokia Here. The quality is impressive and it supports 512x512 tiles, too.