Visually lossless

A non-technical term commonly used to describe the quality of video after it has been through a process or processes: often compression / decompression. Strictly speaking, it can only mean it looks the same, but that does not mean it is the same. So, if the input quality was good, then the output should look the same and so fine for an audience looking at a similar screen. However, if the material is required for a video process, such as pulling a key, or color correction, visually lossless may not be good enough, as the process can be more demanding tasks, such as creating a key single.