from the flat-world dept.
Google has described a projection technique called Equi-Angular Cubemaps that can improve VR/360° video quality:
The image quality issue that plagues spherical video sources is a perspective problem. A traditional 2D video records a predetermined frame and is played back on a display of the same shape and perspective. VR/360-degree video doesn't offer that luxury. Although you can choose which perspective you wish to see, your view is always a fixed resolution and shape, no matter where you look. The image is technically flat, which means the source feed must be warped to fit a flat plane. The process is comparable to what cartographers go through when trying to map the globe to a flat surface. In order to fit the spherical earth map onto a flat image, the perspective must be altered.
[...] Google's Daydream and YouTube engineers came up with a new projection technique called Equi-Angular Cubemaps (EAC) that offers less disruptive image degradation. EAC keeps the pixel count even between cubemap samples, which produces balanced image quality across the board. [...] Google is already putting Equi-Angular Cubemap projection to work. Spherical video playback from YouTube with EAC support is now available on Android devices, and Google said support for iOS and desktop is coming soon. If you want to know more about EAC, Google's blog offers a deeper explanation of the technology, and the YouTube Engineering and Developers blog has additional details.
Google's R&D arm, Google Research, recently dedicated some time and resources to discovering ways to improve the performance of foveated rendering. Foveated rendering already promises vast performance improvements compared to full-resolution rendering. However, Google believes that it can do even better. The company identified three elements that could be improved, and it proposed three solutions that could potentially solve the problems, including two new foveation techniques and a reworked rendering pipeline.
Foveated rendering is a virtual reality technique that uses eye tracking to reduce the amount of image quality necessary in areas covered by the peripheral vision.
The new techniques mentioned are Phase-Aligned Rendering and Conformal Rendering.
Also at Google's Research Blog.
Related: Oculus VR Founder Palmer Luckey on the Need for "Unlimited Graphics Horsepower"
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