[Qgis-user] Georeference png files

[LE LAMER Romain]

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