Sphere cameras

A camera that can take 360 sphere pictures and videos has two fish-eye objectives that capture more than a half of the sphere each. To put those two "half" sphere pictures together at real-time before storing them on their memory the necessary processor power is not available.Therefore the two raw circle pictures are added into a standard jpg picture.

Figure 10.19. Two circles

Rae Sphere Picture


This picture can then later e.g. by an android app converted in a stitch picture containing both pictures and converted to a rectangular projection.

Figure 10.20. Sphere

Sphere picture


Meta data should then be added to let the viewer SW to be know that it is not a regular jpg picture (the same applies also for videos).

Google uses the MIME type application/vnd.google.panorama360+jpg to let it know that it is a 360 degree picture.

Any picture viewer or movie player can be used. More specialized viewers could be installed. But there is also Web support for it as https://pannellum.org/ simply copy and past the web pages and modify them to point to your pictures and movies. The open it in a browser. Additional features as adding hot spots are supported and nothing has to be installed. If it is more frequently used than the used java scripts and the html pages should be installed on a web server.

When adding hot spots their pitch and yaw must be known. panellum allows to pass "hotSpotDebug": true, to is viewer. then mouse clicks write the corresponding pitch and yaw into the browsers console. For Firefox the console can be seen when adding the Firebug plug in.

To observe video the video can be converted from mp4 to webm format that is used by YouTube and sponsored by Google to be a royalty-free alternative (however also mp4 works well). The conversion can be done with ffmpeg:

ffmpeg -i movie.mp4 -vcodec libvpx -acodec libvorbis movie.webm

Note

vpx support must be compiled with ffmpeg and libvpx must be istalled. In Gentoo Linux this is done by setting the vpx useflag.

Instead of installing a special sphere video player to just view a section VLC with its interactive zoom (Tools -> Effect and Filters -> Video Effects -> Geometry ) can be used

Figure 10.21. VLC and sphere videos

Spheres in VLC



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