Fast intra algorithm based on texture characteristics for 360 videos

With the rapid progress of virtual reality technology, 360 videos have become increasingly popular. Given that the resolution of a 360 video is ultra-high (generally 4K to 8K), the encoding time for this type of video is considerably high. To reduce encoding complexity, this study proposed a fast intra algorithm that is based on image texture characteristics. On the one hand, the proposed algorithm determines whether to terminate the coding unit partition early on the basis of texture complexity. On the other hand, the proposed algorithm reduces the number of candidate modes in mode decision according to texture directivity. Experimental results showed that the proposed algorithm can obtain an average time reduction rate of 53% and a Bjontegaard delta rate increase of only 1.3%, which is acceptable for rate distortion performance.