Projecting a Map From Imagery: Photoshop and Flexify

Today we’re going to try something a little different. Quite some time ago, in the hoary days before Flaming Pear LunarCell had equirectangular map outputs, I created this rather nice planetary image.
Zeta-GoldUnfortunately, I lost the settings long before those cool map outputs were added to LunarCell. Later, but well before I started learning the art of mapmaking on Cartographer’s Guild, I roughly traced the image to create this interesting, but neither scaled nor properly-projected “map” of a planet I wound up naming Asdakseghzan, sorta-homeworld of the canine-derived Vugoa. Think Traveller Vargr…
I have no idea what the scale should be, and that “equator” line should probably be ignored in future.

I’d like to create a reasonably projected, fairly well scaled version of the map with some fidelity to the original image.

I started by cropping the space picture down to the circular area covered by the planet in the picture. Then I expanded the canvas size to a square area just large enough to contain the circle. Make sure to save the resulting image.
Zeta-Gold_rawMerge those layers together. Next thing I did was to load the old, traced “map” I had created into Photoshop. Paste it over the square, cropped version of the beauty shot you just made, reduce opacity so that you can see the underlying image, and Edit>Transform>Scale the pasted layer so that the traced shorelines match the shorelines in the underlying picture. This might take a bit of jockeying about and messing with the opacity to get a good idea of when everything fits. Now, I made sure to select the underlying picture image.

Next, I brought up the Flaming Pear Flexify 2 filter to project from an input projection of Orthographic to an output projection of Equitall(to fill the square space). I adjusted the rotation controls till I had the area roughly where I wanted it. I now had at least a credible global projection of the portion of the planet visible in the image. Eventually, I’ll be able to use this to work out the scale of the map.

After that, I selected the resized layer with the traced image, and projected that. All of the settings should remain unchanged, otherwise the layers won’t match up properly.

Once I have the image reprojected, I resize it to 2048×1024 to get the proper aspect ratio for an equirectangular projection. Here is the resulting map.
Zeta-Gold_projectedAnd the composite.
Zeta-Asdakseghzan_compositeNotice the large green area. That is about the area that would have been filled with mapped features if the original image had been a fullan face shot. The distorted rectangle on the west end of that potentially visible area is the portion of the planet that had made it in front of the lens. Part of that is even in darkness. The sacrifices we make for a visually striking picture. Usually NASA doesn’t use imagery from the limb of the planet to create composite maps. Unless they have to. Also notice that I said, “map,” this is the first image worthy of the term. The red area? That wouldn’t have been visible.
Now that I know where this is on the globe, I can set about creating the rest of the world without fear of contradicting this little portion that I’ve already created so much backstory for. Some details will have to change. The equator, for instance, isn’t precisely where I envisioned it, although the match was closer than I’d feared.

What are the potential uses for this? Well, once upon a time, when I was even more of a Trekkie than I am now, I wanted to make maps of some of the planets that the Enterprise was shown orbiting. That’s even more attractive with the often more convincing planets in the remaster, though I’m not as obsessed as I used to be. All you have to do is grab a screenshot, Register the visible portion of the planet to a circular template filling a square canvas, and Bob’s your uncle! Getting features shown in multiple disconnected shots into the correct spatial relationship could be an interesting challenge. I’ll leave that to the readers to try figuring out. Please, post a link to the comments if you find or create a good method… Anyway, this could be an excellent first step to creating your map of Tatooine or Alderaan or Pandora. Or as I did, recovering some old tracing you tried to make into a map.

Another use I really hadn’t thought about before, would be to use a technique similar to the one described here to convert scrawlings on an actual physical globe into a map. Yeah, that’s definitely going in my notebook for a future post. Time to make that dry-erase globe I’ve been dreaming of…

For my next trick, I’ll try repeating this procedure with MMPS and the GIMP. Photoshop has been an awful crash-monster lately, particularly after I use Flexify. I was also impressed by the latest version of GIMP and want to try it out. Finally, I really want to try using open source or at least freely-available tools as much as possible to make my solutions as generally useful as possible. I’ll post that by monday. I promise…

Thank you for your attention. Please feel free to ask for clarification, make comments, or give ideas for improvements.
The Astrographer

This entry was posted in Building a Worldmap, Mapping, Planetary Stuff, Projects, World Building and tagged , , , , , , , , . Bookmark the permalink.

1 Response to Projecting a Map From Imagery: Photoshop and Flexify

  1. Pingback: Races of the UNSEO – The Vugoa | Astrographer

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