I have a world map which I assumed used a Mercator projection but when I tried to plot points on it using a formula for the Spherical Pseudo-Mercator projection (from here: http://wiki.openstreetmap.org/wiki/Mercator#Python) but the Y coordinates seem off. How can Identify which projection is it using? Can someone provide pseudocode/Python for transforming lat,long pairs to x,y pixels for it? If it may help, this image comes from a KML file.
<GroundOverlay>
<name>1986-2010</name>
<altitude>0</altitude>
<altitudeMode>clampToGround</altitudeMode>
<Icon>
<href>KG_1986-2010.png</href>
</Icon>
<LatLonBox>
<north>90</north>
<south>-90</south>
<east>180</east>
<west>-180</west>
</LatLonBox>
</GroundOverlay>