Meenakshi Singhvi
Director,
All India Radio

360° video-viewing all around

The photography and videography world continues to evolve. The latest 360° video, also known as spherical video or immersive video, is a revolutionary video technology, providing unlimited opportunity to user and content creators. 360° video technology, has opened up new horizon in the media industry because of already existing network bandwidth and non-traditional delivery methods, which made it possible for end-user, not only to enjoy 360° video content but to live-stream their own video on social media platforms. Affordability of 360° cameras and widespread availability of smart mobile phone devices further helped this technology to gain momentum.

360° video cameras give a spherical video. The camera uses two or more super wide lenses to see in every direction at once, and then stitches the video captured by each lens together to make a seamless video.

Here, a scene is captured not as a rectangle but on the inside of a sphere. When we are viewing a 360° image or video, we are effectively positioned in the middle of this sphere, can navigate either by physically moving our smart device, by dragging across a touchscreen, or moving a window in our browser.

The main benefit of 360° cameras is the ability for the devices to provide up to 100 percent coverage of a scene with no blind spots. The lens is mounted in a fixed position and does not need to move or rotate to capture an entire scene. Everything is visible all the time, both on live and playback.

How 360° camera works
360° camera usually has two wide-angle lenses mounted back-to-back, and each captures a 180° half sphere: everything from behind the camera to the camera’s front and, everything from above the camera to below the camera. Two hemispheres of sensor data are combined and stitched into one data that is updated 30 or 60 times per second. This process is done either by the camera itself, or using specialized software that can analyze common visuals and audio to synchronize and link the different feeds together.

A more advanced camera would have more than two sensors, the more sensors the better. The best 360° cameras include functions like automatic stitching, image stabilization, live-streaming, and higher resolution up to 8K. Expensive camera rigs were required earlier and lot of time was consumed for editing, but new breeds of camera are having in camera stitching software, light in weight, and portable design making these devices attractive for masses. Mostly 360° camera models can be connected to a smartphone through an app that allows users to easily control and adjust the camera’s settings.

As the 360° camera captured the whole surroundings, we have to be even more careful not to make any slip-ups or have unwanted objects or people in the scene. This can sometimes present a real challenge for filming.

360° videos can be viewed on PC, smartphones, or dedicated head-mounted displays. Users can pan around the video by clicking and dragging. On smartphones, internal sensors such as the gyroscope can be used to pan the video based on the orientation of the device.

Recording and editing aspects-360° video
As 360° camera records everything around us, including tripod, so we need to go for a travel tripod, especially the compact one, typically with a ball head that we can adjust with a knob instead of an extended arm.  Not only the tripod needs to be out of shot, keeping oneself out of the shot is another worry sometimes. Thankfully, we have got various 360° cameras available that can be connected to a mobile app and can be remotely recorded and paused.

Since two cameras strapped back to back are used, there is a parallax effect, where the images may not look perfectly aligned with each other. The software that comes with these cameras mostly mitigates the parallax effect by making it barely noticeable glitch. Another issue that one needs to take care while editing 360° video is that stitch lines should look less noticeable by making sure that it does not pass through any object or visually interesting areas.

When it comes to edit and add titles it is difficult in 360° video than traditional video. The final output of 360° cameras is a sphere instead of a flat image. Therefore, we need to distort title image or text to match the spherical video’s curvature so that it looks flat, professional-looking.

These 360° cameras utilize fisheye lenses. These ultra-wide angle lenses substantially distort the image, especially at the periphery. This visual distortion effect that is created when using ultra-wide angle lenses is commonly referred to as a fisheye effect.  It means to keep some optimum space between the camera and the subject, not too much to lose clarity, may be 3-5 ft from the subject.

Software based digital manipulation can also be applied on the image to dewrap the area of the original wrapped fisheye, to be converted to have the look and feel of a more traditional video stream.

360° video vs 3D video vs virtual reality
Many people use 360° video, 3D video and virtual reality interchangeably, which may lead to confusion. In 360° video, image is captured from every angle, thus allowing the viewers to explore the image in all directions. To view 360° video a viewer does not always need to wear goggles, although in some cases, they may.

3D video gives you depth of field but it is unidirectional. Capturing 3D in one direction can only happen with at least two lenses, as we reproduce what human eyes can do in stereo. To consume 3D video, you will need a 3D headset and a good cellphone. Thus, 3D video has depth of field, but the viewpoint is limited, whereas 360° video is full 360°, but no depth of field. As technology becomes cheaper, all the 360° videos might become 360 3D videos.

Virtual reality (VR) can be defined as an artificial, computer-generated simulation or recreation of a real-life situation. In VR, artificial 3D environment is created, 360° video, however is a live action capture of a real world event without the need for a pre-rendered digital environment.

Audio portion
With immersive 360° video experience, the audio production is as important as the visuals. It is absolutely vital that the sounds we hear are coming from the right direction in sync with video.

Most of the 360° cameras in the market offer an in-built microphone to capture ambisonics audio, however we may use separate audio recording device also to get the best results. While using an external recording device to capture audio, we will need to synchronize the audio and video in our video editing software.

360° video delivery
Delivering 360° video streams is a challenge, which requires robust network bandwidth and latest coding technology. To overcome the challenges, tiled a 360° video delivery method is used. With this approach, content is split so the highest resolution video is delivered for the content in the user’s field of view, while the rest of the video stream is delivered in lower resolution. It results in significant reduction in the total size of the stream, with comparatively minimal loss of perceptible quality.

Modern compression standards like HEVC/H.265 and the future VVC/H.266 help make these new applications possible, because they deliver video of the same or superior resolution in fewer bits. 360° live video streaming option is currently available on many popular platforms, such as YouTube, and Facebook.

Conclusion
360° video is emerging as a new way of offering immersive visual experience. Apart from entertainment, 360° video technology is widely utilized in the field of training, education, medical, journalism, gaming, e-learning, and security industry.

There are many different kinds of 360° cameras currently available in the market. GoPro Fusion, Garmin VIRB 360, 360Fly 4K, Insta360 ONE X, Rich Theta V, etc., are few of the good names.

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