# How can I use Mathematica to convert a Mollweide projection map to Equirectangular?

So, disclaimer, I have zero experience with Mathematica, and I apologize in advance.

I'd been looking for some software capable of converting between map projections for some time (in order to convert this Mollweide map to an equirectangular projection so that it may be more easily imported to other programs such as GPlates) when I stumbled across this thread which, while a different goal, had a step which did exactly what I needed to do.

So, elated by this discovery, I downloaded the trial version of Mathematica, watched a couple videos to get a handle on the basics, and pasted the code from the thread into the program. However, when I hit "run code," It did...nothing. All I got was the following output:

ImageForwardTransformation[(original image of map), Null,
DataRange -> {{-2 Sqrt[2], 2 Sqrt[2]}, {-Sqrt[2], Sqrt[2]}}, PlotRange -> All]


What am I doing wrong, and what can I do to make the code work?

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• The code in the linked thread works fine for your image (see i.sstatic.net/QbATO.jpg). Are you sure mollweidetoequirect was defined correctly? The Null in your ImageForwardTransformation output makes me think it was incorrectly defined. Does running ClearAll[mollweidetoequirect] then redefining it fix things? Commented Dec 29, 2021 at 2:40