<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">You can use a pngw. Try saving your map as an image for an example.<br>Cheers.<br><br><div class="gmail_quote">On 22 December 2019 17:52:10 EET, Nicolas Cadieux <nicolas.cadieux@archeotec.ca> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div dir="ltr">Hi,</div><div dir="ltr"><br></div><div dir="ltr">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.</div><div dir="ltr"><br></div><div dir="ltr"><a href="https://en.wikipedia.org/wiki/World_file">https://en.wikipedia.org/wiki/World_file</a></div><div dir="ltr"><br></div><div dir="ltr">Nicolas</div><div dir="ltr"><br><blockquote type="cite">Le 22 déc. 2019 à 10:16, LE LAMER Romain <rlelamer@hotmail.fr> a écrit :<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><span>Hi,</span><br><span>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)</span><br><span>1024 tiles in Longitude and 512 tiles in Latitude = 524288 tiles.</span><br><span>Each tile is named as follows: map_Z_X_Y.png</span><br><span>Z => zoom (11).</span><br><span>X => from 0 to 1023.</span><br><span>Y => from 0 to 511.</span><br><span></span><br><span># If I say no nonsense, I can, by calculation, know the Longitude and Latitude:</span><br><span>lonN = (360 * (X / 1024)) - 180.</span><br><span>latW = 90 - (180 * (Y / 512)).</span><br><span></span><br><span>In the same principle, I can determine the South East coordinates.</span><br><span>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 °</span><br><span>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 °</span><br><span></span><br><span>lonE = lonN + 0.3515625</span><br><span>latS = latW - 0.3515625</span><br><span></span><br><span>How can I add these coordinates to the png file?</span><br><span></span><br><span>Thanks</span><br><span>_______________________________________________</span><br><span>Qgis-user mailing list</span><br><span>Qgis-user@lists.osgeo.org</span><br><span>List info: https://lists.osgeo.org/mailman/listinfo/qgis-user</span><br><span>Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user</span></div></blockquote></blockquote></div><br>-- <br>Please excuse my brevity.</body></html>