Nyquist is a noun, not an adjective, for Harry Nyquist. The Nyquist–Shannon sampling theorem is applicable to analog to digital conversion of signals (continuous to discrete), images are a type of signal.
El mié., 30 sept. 2020 a las 20:25, Mark Filipak (ffmpeg) (< markfili...@bog.us>) escribió: > Nyquist [adjective]: 1, Reference to the Nyquist–Shannon sampling > theorem. 2, The principle [1] that, to most faithfully reproduce an > image at a given digital display's resolution, the samples must be > made at or above twice the display's resolution, both horizontally & > vertically [2]. > [1] The Nyquist principle applies to film sampling and to digital > cameras, but, provided that resolution is unchanged, not to > transcoding (because the transcoder inputs are already digital). > As proved by the improved appearance of SD media made from 2K > samples, SD mastering prior to the advent of 2K sampling (e.g. > DVDs mastered before the advent of HD) generally ignored the > Nyquist principle and were undersampled. HDs sampled at 2K and > UHDs sampled at 4K are likewise undersampled. > [2] As a convenience, the Nyquist threshold is currently (in 2020) > specified solely by horizontal sample count rounded up to whole > kilo-samples (2K, 4K, 8K). > display Nyquist threshold > UHD 16:9-2160: 3840 x 2160 8K > 4:3-2160: 2880 x 2160 8K > HD 16:9-1080: 1920 x 1080 4K > 4:3-1080: 1440 x 1080 4K > SD 16:9-576: 1024 x 576 4K > 4:3-576: 768 x 576 2K > 16:9-480: 853 x 480 2K > 4:3-480: 640 x 480 2K > > -- > What if you woke up and found yourself in a police state? > African-Americans wake up in a police state every day. > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
