A spherical video coding method and device

Abstract

The invention provides a spherical video coding method and belongs to the video coding technology field. The method comprises steps that uniform sampling of a center circumference of a spherical center of a spherical video is carried out according a first sampling frequency; an included angle and arc length of two adjacent sampling points on the center circumference are respectively taken as a standard angle and a standard distance; according to the standard angle, each coaxial circumference which is in coaxial relationship with the center circumference is determined; uniform sampling of each coaxial circumference is carried out according to the standard distance; all the sampled sampling points are mapped to a target plane video; coding of the target plane video is further carried out. Through the method, problems of relatively low coding efficiency caused by non-uniform mapping, and high coding complexity and relatively low efficiency caused by high prediction difficulties among planes of different plane videos and obvious boundaries along the different plane videos in the prior art are solved, so the spherical video can be uniformly mapped to one plane video, coding complexity is effectively reduced, and thereby coding efficiency is improved.

Description

technical field [0001] The present invention relates to the technical field of video coding, in particular to a spherical video coding method and device. Background technique [0002] With the rapid development of multimedia communication, many spherical videos appear, and spherical video coding is usually converted to planar video coding. [0003] In the prior art, there are mainly three methods for converting a spherical video into a plane video: the latitude and longitude diagram method, the hexahedron method, and the pyramid method. As shown in Figure 1(a), any point P on the spherical video is represented by the angle α between the 0-degree longitude J0 and the 0-degree latitude W0 by the longitude-latitude diagram method, and the angle α and angle β are calculated. Sampling with the same number of points, so as to obtain the histogram corresponding to the sampling point as the plane video corresponding to the spherical video; as shown in Figure 1(b), the hexahedron me...

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Problems solved by technology

[0004] It can be seen that the latitude and longitude map method samples the same number of points at different latitude angles, which will result in a smaller sampling distance for latitude lines with small latitude angles, and a larger sampling distance for latitude lines with large latitude angles. This uneven sampling leads to low coding efficiency. ; while the hexahedron method maps the points of the spherical video to the hexahedron, because the distance between the sphere and the hexahedron is not fixed, the points mapped to the hexahedron are not uniform, and the hexahedron method stitches six plane videos together. It is more difficult to predict and there are obvious boundaries between different plane videos, which leads to complex coding and low efficiency. Similarly, the regular pyramid method also has similar problems to the regular hexahedron method

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