November 2010 – PanoTwins

Reprojecting equirectangular images

This gallery shows a talk I held at the PanoTools meeting 2009 in Timişoara. It discusses some aspects of reprojecting equirectangular images.

All of the aforementioned projections have plenty of parameters to play with! In this overview you see the large impact of only one parameter to the resulting image! Try some of the projections and play with the parameters! — Slide 20/20

Again a combination of a stereographic projection followed by a Droste effect was used to produce this image. — Slide 19/20

The Droste effect can also be combined with a stereographic projection to produce this spiral view of the equirectangular. The image was first transfomed to stereographic projection. The result was then fed to Mathmap. — Slide 18/20

Combining the Quincuncial projection with a Droste effect can produce really astounding images. — Slide 17/20

The Quincuncial Single projection maps again onto a square, the zenith is in the centre, the nadir is moved to all the four corners. Again this image can be tiled to fill up your desktop background. — Slide 16/20

This rotated Quincuncial projection was also produced using Mathmap with the Gimp. When placing two of these images next to each other you get an "equirectangular" image with a FoV of 720x180, that can be fed to a panoramic viewer! — Slide 15/20

The Quincuncial projection maps the original 2:1 aspect ratio image onto a square. Thus this projection is interesting for tiling, however you have to flip the adjacent images. The software to produce this projection was the Mathmap plugin for The Gimp. — Slide 14/20

The transverse Vedutismo projection was used to remap the equirectangular images. PTGui and Hugin support this projection. — Slide 13/20

The transverse Mercator projection can be produced using PTGui or Hugin. — Slide 12/20

This triplane projection was produced using Hugin. — Slide 11/20

This image was produced using two separate images. Both are Albers Conic projections, that add up to a FoV of 720x180. Use Hugin and an image processing tool to generate it. — Slide 10/20

The sinusiodal projection shows the complete equirectangular and can be produced using Hugin. — Slide 9/20

When the zenith is in the centre of the image the little planet changes into a tunnel projection. The projection can be produced using Hugin or PTGui. — Slide 8/20

The stereographic down projection transforms the equirectangular to a "little planet". Use PTGui or Hugin to remap your equirectangular image. — Slide 7/20

This stereographic projection with a FoV of 250° can be achieved using either PTGui or Hugin. The equirectangular is not completely visible. — Slide 6/20

A fullframe projection can be produced using Hugin or PTGui. The equirectangular is completely visible in this projection. — Slide 5/20

The projection onto a sphere shows only half of the equirectangular (FOV = 180x180). Can be mapped using Pano2VR. — Slide 4/20

Circular projection. The image shows the complete equirectangular image (FoV is 360x180). Can be mapped using PTGui, Hugin or Pano2VR. — Slide 3/20

This image is used as the "real world" example. On the subsequent pages the reprojected images are always shown side by side. — Slide 2/20

This presentation tries to show different mappings for equirectangular panoramas. This artificial image is used to illustrate them. Note the yellow part, the zenith, and the black part, the nadir. — Slide 1/20

Towerview St. Paul, West, South

During Oktoberfest the tower of St. Paul can be ascended.

Turmblick St. Paul, Westen, südlich in München

Reprojected Subway Pedestrian Passage

This image shows a reprojected version of this panorama.

Reprojected British telephone booth

This image shows a reprojected version of this panorama.

Geotag Icon Show on map

Reprojected wooden framework bridge

I uploaded a new panorama @360cities. These images show reprojected versions of it.

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