How can I re-center, reproject, and crop a stitched 360x180 equirectangular panorama?

Question

I have a fully stitched 360x180 panorama made with Google PhotoSphere. The app only saved the final panorama, not the original source frames. I want to change the center/view direction, choose a different projection, and crop/export a new panorama or flat view at full resolution instead of taking screenshots from a viewer. Can this be done in Hugin or similar software with an already-stitched equirectangular image?

360-photo equirectangular reprojection hugin panorama

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

10y ago

user27440 · Accepted Answer

Using Hugin

Yes, since Google PhotoSphere panos are stored as equirectangular projections you can use Hugin to remap to other projections.

Go into the Interface → Advanced (or Expert) mode.
Click the Add Images... button to load the stitched panorama.
Set the Lens type to Equirectangular and the HFOV to 360.

This will load your 360x180 as a 360x180.
Go into the GL preview window.
Use the Move/Drag tab to change the viewpoint.

Dragging horizontally changes yaw, dragging vertically changes pitch, right-dragging changes roll.
Use the Projection tab to select a different projection.

Watch your FoV setting, since not all projections play nice with 360.
Use the Crop tab to set the crop.
Once everything looks the way you want it to, save the Hugin project (.pto) file, and go to the Stitcher tab, select the file output format and size you want, and click the Stitch! button to create your new panorama.

Other Methods

You could also use the Flexify 2 Photoshop plugin from Flaming Pear, if the list of projections that Hugin offers is too modest for your taste. But it does cost money and it requires a Photoshop license. OTOH, the list of projections is very impressive. This is actually my go-to tool for reprojecting.

If nobody has the remapping you want to try, and if you're geeky and hands-on with math and code, you could also use the Gimp with the Mathmap plugin. There's a Flickr group dedicated to this.