How do I distort an existing map so that it matches the Robinson(?) projection used in the standard q-bam world map projections used in this community?
I thought I had a system that worked, involving a bunch of Excel formulas to calculate a rotation and a resize scaling factor, but for anything that is far removed from zero on both the latitude and longitude axes, it seems I also need to include a "shearing" factor, which is pretty much impossible to calculate automatically (or at least, I have no idea how).
What I've been doing with the maps I've drawn so far in the q-bam thread is to rotate/resize them using my Excel formulas, then create a new semi-transparent layer on top of the main q-bam layer, and trace the borders. However, this won't work for most regions of the world and most maps, due to the shear distortion that is also present in most parts of the overall projection.
I have good knowledge of Paintshop Pro (v8). I also have use of Photoshop (v7), but would need step by step tutorials for anything involving that.
Is there a way to stretch an arbitrary map image as a layer to match a second map layer for "tracing" purposes?