conversion of x and y coordinates to latitude and longitude

[bhooshan]

sir ,

Actually i have a gui which contains qcustomplot widget with a map inside the widget. if i click on the widget am able to get the cursor position on the map with x and y values . now i need to convert that x and y coordinates into latitude and longitude .
presently am using qt4 . can any body suggest me how to do this . my specific request is to suggest me the solution at the earliest

[d_stranz]

If you know the origin position and size of the image in pixels and the start and end longitudes and latitudes of the map, then this is an easy algebra problem.

[kaufenpreis]

I think the next article can help you - how-to-convert-x-y-coordinates-to-longitude-latitude-using-quantumgis