Along the base of Vera Rubin Ridge, (Sites 64-65, Sols 1726-1812, Jun 14-Sep 11 2017) |
Along the base of Vera Rubin Ridge, (Sites 64-65, Sols 1726-1812, Jun 14-Sep 11 2017) |
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#101
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Member ![]() ![]() ![]() Group: Members Posts: 362 Joined: 13-April 06 From: Malta Member No.: 741 ![]() |
Time for a new topic in line with Curiosity's new location.
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#102
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Solar System Cartographer ![]() ![]() ![]() ![]() Group: Members Posts: 10196 Joined: 5-April 05 From: Canada Member No.: 227 ![]() |
The circular part of a circular projection is just Photoshop: Filter-Distort-Polar Coordinates. If you use it on a raw panorama you get what is usually referred to as a polar projection. Every vertical column of pixels is mapped onto a radial line from the projection center to the circumference. So the extreme foreshortening near the horizon is the same in the raw pan and the polar projection.
I perform an extra step for my circular projections, which is why I use a different name for them. I could call it Stooke's Fudged Polar Projection, but 'circular' is shorter. I change the radial scale so the outer part is greatly exaggerated and the inner part shrunk - in effect removing the foreshortening to create something a bit more like a map. It still contains a lot of relief distortion so it's not really a map-like geometry - to fix that you need a DEM. In the old days I left it like that, causing high features on the horizon to be greatly exaggerated in height. Now I shrink the horizon features a bit to try to create a horizon closer in appearance to the original panorama. A total fudgerooney. But I like the effect and it makes locations easy to compare with a HiRISE image. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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