For key frames, traditional video
intraframe coding framework is adopted, or high-rate CS codec is introduced to ensure the high quality of reconstructed key frames.
[30] Han Huang, Yao Zhao, Chunyu Lin and Huihui Bai, "Fast
Intraframe Coding for High Efficiency Video Coding," KSII Transactions on Internet and Information Systems, vol.8, no.3, pp.
The difficult challenge in the design of the MPEG algorithm is the following: on one hand the quality requirements demand a very high compression not achievable with
intraframe coding alone; on the other hand, the random access requirement is best satisfied with pure
intraframe coding.
One technique, interframe coding, transmits only the changes in the picture from frame to frame; the other, intraframe coding concentrates on coding high-detail areas of the picture at the expense of the less detailed areas.
Since the compression is applied to each frame, irrespective of scene changes, intraframe coding is comparatively motion-independent.
Compression Labs which pioneered intraframe coding, recently developed an improved codec that uses both intraframe and interframe coding techniques.
Even for intraframe coding, it is still far away from real-time application [4].
In this paper, a fast intra mode decision algorithm is proposed for HEVC intraframe coding. The proposed algorithm consists of three techniques to reduce the number of candidate modes for RD optimized mode decision.
Intraframe coding is used for the first picture and for later pictures after a change of scene.