Hi, To my knowledge, and I may be wrong, you cannot insert a geotag in a .png. Try saving as .tif. That should be georeferenced. If you absolutely want to use a .png, you will need to create a world file. To see how they work, just export the map window using .png. A world file will be created and will contain the information you are looking for. The world file is a text file that can be opened with notepad++ or any text editor.
https://en.wikipedia.org/wiki/World_file Nicolas > Le 22 déc. 2019 à 10:16, LE LAMER Romain <[email protected]> a écrit : > > Hi, > I have a complete map in tiles of 256 x 256 px in png format not > georeferenced. (if I open them in QGIS they are superimposed on each other) > 1024 tiles in Longitude and 512 tiles in Latitude = 524288 tiles. > Each tile is named as follows: map_Z_X_Y.png > Z => zoom (11). > X => from 0 to 1023. > Y => from 0 to 511. > > # If I say no nonsense, I can, by calculation, know the Longitude and > Latitude: > lonN = (360 * (X / 1024)) - 180. > latW = 90 - (180 * (Y / 512)). > > In the same principle, I can determine the South East coordinates. > I know that the whole map is divided into 1024 tiles of 256px in longitude, > 1024 x 256 = 262144px for 360 ° so a tile = (256 x 360) / 262144 = 0.3515625 ° > Same reflection for the latitude, 512 tiles of 256px or 512 x 256 = 131 072px > for 180 ° so a tile = (256 x 180) / 131 072 = 0.3515625 ° > > lonE = lonN + 0.3515625 > latS = latW - 0.3515625 > > How can I add these coordinates to the png file? > > Thanks > _______________________________________________ > Qgis-user mailing list > [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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