1. Technical Field
The following embodiments generally relate to an image decoding method and apparatus and an image encoding method and apparatus and, more particularly, to a method and apparatus that adaptively perform encoding and decoding based on the quality of an image.
2. Description of the Related Art
With the continuous development of the information and communication industries, broadcasting services having High-Definition (HD) resolution have been popularized all over the world. Through this popularization, a large number of users have become accustomed to high-resolution and high-definition images and/or videos.
To satisfy users' demands for high definition, a large number of institutions have accelerated the development of next-generation imaging devices. Users' interest in Ultra High Definition (UHD) TVs, having resolution that is more than four times as high as that of Full HD (FHD) TVs, as well as High-Definition TVs (HDTV) and FHD TVs, has increased. As such interest has increased, image encoding/decoding technology for images having higher resolution and higher definition is required.
In new video services such as UHD service, the necessity for a High Frame Rate (HFR) video has increased. For example, a high frame rate may be a frame reproduction rate above 60 Frames Per Second (FPS).
However, in order to provide such an HFR video, a problem may arise in that the amount of video data increases. Further, with the increase in the amount of video data, expense-related problems and technical problems may occur in transmitting and storing video.
Fortunately, due to the visual properties of a human being, HFR is not necessarily required in all situations. For example, most persons cannot perceive the difference in image quality or the degradation of image quality between 30 FPS video and 60 FPS video in a video in which motion is scarcely present.
That is, when FPS is equal to or greater than a specific threshold value depending on the contents of video, most persons may not perceive the difference in image quality due to the cognitive features of a human being even if FPS is further increased.