Converting Longitude & Latitude to X Y on a map with Calibration points

Question

If i have a jpeg map with size sizeX, sizeY

and some calibration points on the map (X, Y, Lon, Lat)

What would be the algorithm for calculating the corresponding XY point in the map with a given Longitude / Latitude pair?

Answer 1

Here's what worked for me, without so much bs.

int x =  (int) ((MAP_WIDTH/360.0) * (180 + lon));
int y =  (int) ((MAP_HEIGHT/180.0) * (90 - lat));

The lat,lon coordinates were given to me by Android devices. So they should be in the same standard used by all Google Earth/Map products.