I understood, and I agree.
As I said, I wasn't very clear. I think describing The GIMP as a bitmap program with layers will leave a wrong impression with some people who don't have a lot of technical knowledge, leading them to think that The GIMP produces bitmap graphics that one can open in programs like MS Paint with file extensions like BMP, JPG and PNG. This, of course, isn't what The GIMP does, It produces a raster graphic file that consists of one or more layers, each of which is a bitmap. To make this into a flat bitmap that's the kind of file many understand a bitmap to be, the content of the native XCF file graphic has to be flattened and exported as a BMP, JPG, PNG or whatever. I thought this difference should be mentioned.The XCF thing I agree with you. It didnt appear from post #14 as though that was what you were saying. But with that clarification - I agree.
If I counted the zeroes right, 300000000 bytes = 300 MB.
That's a pretty good performance statistic.
Not a plus-or-minus point, but a curiosity. You mention the PNG conversion being faster than the BMP and JPG conversions. As I understand it, all three were exports from Map Forge. A question then: Assuming (perhaps incorrectly) that the conversion was a direct conversion from memory to new file, did you compare the JPG and BMP export times to the times that would result in converting an exported PNG file from Map Forge into BMP and JPG files with an external program?
Whatever the case, I'll be watching this with interest. Even if the end result is nothing more than what amounts to a new and improved version of 32-bit Dundjinni, it's still more than we have now. I'm on your side. I hope you succeed!
Good luck!